Breast Health
A word from Dr David Ingram
Dr David Ingram is a Specialist Surgeon in the management of Breast Diseases at the Mount Hospital Medical Centre.
Check back here for regular updates on treatments and new developments from Dr Ingram.
BREAST CANCER SCREENING IN OLDER WOMEN
Listed July 18 2008
Having regular screening mammograms has been shown to save lives by detecting the cancer at an early stage ie: before it has spread to distant parts of the body. Studies have shown that breast cancer mortality in a population drops by around 30% once a breast screening programme has been introduced, although it does take at least 5 years for this to become apparent.
In most countries breast cancer screening is promoted for the 50-69 year age groups. Why choose this group? Why not all women? For a start, younger women have dense breasts and mammography does not work so well in dense breast tissue and may miss cancers. Studies have shown that if women 40-50 are screened the mortality does fall, but not to the same extent as for older women (there is a less than 20% decrease in breast cancer mortality in the 40-50 age group). Nevertheless, I still think this is beneficial for women 40-50. One presumes that the reason screening is not promoted in older women is that governments think that these women have a shorter life expectancy and so have less to gain by screening, and so save money by not screening this group. I believe such an approach is wrong and even rather offensive, as women 70 or more may well live for another two or three decades and their lives are just as important, and detecting and treating breast cancer at an early stage is just as vital.
A recent study from the Netherlands has been reported where women 70-75 were offered two yearly mammograms, starting back in 1998. Overall, 72% of women offered this service in the period 1998-2000 took it up, and currently the participation rate in this age group is 78%. Breast cancer mortality rates in this group have fallen by nearly 30%, making it a worthwhile service and saving many lives.
Women in Western Australia who are 70 or more can attend for a screening mammogram by telephoning 132050 but they are not automatically contacted like women in the 50-69 year age group.
European Breast Cancer Conference April 2008
MICRO-ARRAYS - NEW HELP IN DECIDING WHO WILL BENEFIT MOST FROM CHEMOTHERAPY
Listed July 18 2008
Overall around 25-30% of women who develop breast cancer and only have it treated by local treatments rather than systemic treatments, will have it return at some stage in future years, usually deeper in the body in the form of metastases (secondaries). By having some form of adjuvant systemic therapy, either chemotherapy, an anti-oestrogen such as tamoxifen, or a new targeted therapy as discussed elsewhere in this newsletter, or a combination of the above, this risk of recurrence can be halved. Thus less than 15% of women who develop breast cancer will die from the disease. Looking on the brighter side, 85% will never have any further problem and this is likely to continue to improve as new drugs come on the market.
A problem for us who treat breast cancer is working out who will benefit and who may not need systemic treatments, especially chemotherapy which is relatively toxic. We currently get some guidance by doing tests on the cancer, for example if oestrogen receptor positive we give anti-oestrogens such as tamoxifen as these will be of benefit with relatively few side-effects, and if HER2 positive then Herceptin will help. The real difficulty is deciding who should have chemotherapy and who may not need it. As mentioned above some 70%of women will never have any further trouble even if not given any systemic treatment, and so giving them chemotherapy is unnecessary. However there is no way of knowing who would benefit from chemotherapy and who does not need it. We get some idea from the pathology - for if lymph-nodes are involved , it is high grade (more aggressive), if young, if the tumour is large, or if oestrogen receptor negative, then chemotherapy is likely to significantly reduce recurrence.
Recent research is helping sort this out, particularly for the large group of women with no lymph-node spread, oestrogen receptor positive, less than 2 cm and grade 2 tumours. Should they have chemotherapy or just an anti-oestrogen? A new new technology has been developed called micro-arrays. In this test a piece of cancer tissue is processed such that 25,000 genes in it can be analysed automatically. By looking at differnet cancer types and outcomes it has been found that there are less than 70 genes which are important in determining if metastasis will or will not occur. Thus by doing a ‘gene profile’ on their tumour, women with breast cancer can be categorised into high or low risk of recurence, and the high risk women treated more aggressively with chemotherapy and the low risk can avoid chemotherapy and just take an anti-oestrogen. While not perfect, these tests have shown a lot of promise and are certainly better than what we do at the moment which is really just an educated guess. Two companies produce these commercially at the moment, a US product called Oncotype DX and a Dutch product called the Mammotest, and in Australia we can access them although they are sent to US or Holland for testing and a result comes back in 10-14 days. They are expensive costing around $3000-4000 with no refund from Medicare or your health fund - at this point in time anyway. There are a couple of large clinical trials underway to test this technology in women with breast cancer - one in US and the other in Europe and while the results won’t be ready for a few years, I expect this will be the way of the future.
European Breast Cancer Conference April 2008
CANCER RISK INCREASED BY WEIGHT GAIN
Listed 27 May 2008
A recent review of more than 282,000 cases of cancer has confirmed that wieght gain increases the risk of devaloping cancer.
A weight gain of around 15 kg increases the risk of oesophageal cancer by 52%. thyroid cancer by 33%, colonic cancer by 24% and kidney cancer by 24% in men; and for women it was 51% for oesophageal cancer, 59% for uterine cancer, 59% for gallbladder cancer, and 34% for kidney cancer. Weight gain is also known to increase breast cancer in post-menopausal women.
In some studies it has been shown that there is a dose response ie: the higher the weight gain the greater the cancer risk.
There are a number of possible mechanisms by which weight gain might increase cancer risk and these are mostly invloving hormone systems including insulin, insulin-like growth factor, and adipokines.
Lancet 2008
MODERN TREATMENTS HALVE THE RISK OF DYING FROM BREAST CANCER
The Early Breast Cancer Trialist Group based in Oxford, UK, have been reviewing breast cancer studies for many years and now have data on 350,000 women treated from breast cancer in 400 trials.
It is apparent from data that a middle-aged woman treated for breast cancer now is only half as likely to die frm breast cancer as someone diagnosed 25 years ago, thanks largely to improved treatments. In particular it is the more widespread use of chemotherapy, antioestrogen therapies and radiotherapy which have helped most in reducing breast cancer deaths.
San Antonio Breast Cancer Symposium Dec 2007
INCREASING INCIDENCE OF BREAST CANCER IN LESS AFFLUENT COUNTRIES
Breast cancer as long been recognized as a disease of alluent countries, and as a country becomes more westernised so it's incidence of breast cancer rises. For example, breast cancer rates in Japan, Singapore and Korea have doubled of tripled in the last 40 years, and in China it is rising rapidly having increased 20-30% in the past decade, mostly in urban areas.
Rates of breast cancer in east Asia are around 21/100000, in Africa around 23/100000, while in Europe it is 85/100000 and the US 101/100000. The reasons believed to contribute most to this high incidence as a result of 'westernisation' is dietry change, decreased exercise, obesity, delayed reproduction, fewer children, and probably HRT use. As regards to diet a high fat, low vegetable and low soy intake have all been implicated in breast cancer devalopment but are difficult to prove.
Although having a low incidence, if an African woman devalops breast cancer she has close to a 70% chance of dying from the disease compared to less than 20% in North America, probably due to late presentation of the disease and inadequate resources for treatment. In addition, breast cancers in Africa are often more aggresive and the reason for this is unknown.
As poor countries become more affluent and 'westernised', there will be an inevitable increasing burden of breast cancer. knowing how to deal with this is difficult, especially as the governments of devaloping countries have many competing priorities for their limited budgets, and it is likely that breast cancer will be fairly low on their agenda.
New England Journal of Medicine Jan 2008
ANOTHER BREAST CANCER GENE HAS BEEN FOUND
Listed 28 April 2008
A study from Denmark has found that women who were born with a genetic mutation called CHEK2 had a 37% (> 1 in 3) chance of developing breast cancer by age 70 if they have a family history, and > 1 in 5 if there is no family history.
We have long known that women with BRCA1 and BRCA2 genetic mutations have a high risk of developing breast cancer (60-80% chance by age 70 or around a 2 in 3 chance).
These figures can be compared to the general population where the risk of developing breast cancer is around 1 in 8.
Although not studied routinely, it is likely that the CHEK2 gene will be included in genetic studies for women with a strong family history of breast cancer in the future.
Journal of Clinical Oncology 2008
BREAST MRI AS A SCREENING TOOL
Previously I have talked about the fact that breast MRI is more sensitive at detecting breast cancer than mammograms ie: it is less likely to miss a breast cancer.
New information was published recently which showed that women at high-moderate risk of getting breast cancer and who were screened annually, were more likely to have their cancer found by MRI. In this study 40% of cancers were detected only by MRI, 26% by MRI and mammography, 18 % by mammogram alone, and in 16% neither method found the cancer.
MRI is by far the most accurate breast cancer detection method but even so it is not perfect and so we recommend that women having MRI also have a mammogram and clinical examination. An ongoing problem with MRI is the cost, being around $700 with no rebate from Medicare or your health fund. It is still unknown if or when the government will start providing some funding for breast MRI.
San Antonio Breast Cancer Symposium Dec 2007
BENEFITS OF REGULAR MAMMOGRAPHY CONFIRMED
Listed 4 April 2008
While screening mammograms are not perfect, a recent review of all previous studies of screening mammography found that it will prolong the life of one in every 2000 women who have a regular mammogram for 10 years. On the down side, some women will have a mammogram which did not show their cancer and where the cancer will present later as a lump, and some women will have a cancer found which would be so slowly growing that it would never have cause any trouble if left untreated.
Overall, we believe screening mammography is very worthwhile and while the government promotes it for the 50-69 year age group, I believe it should start at 40 and continue for as long as you are well enough to attend. Breast Screen WA will do mammograms from 40 onwards if you call them, and they will contact you by mail once you reach 50 and continue this every two years until you reach 70. From 70 they will continue to do mammograms, but only if you telephone and make an appointment. The telephone number for appointments is 132050.
SEDENTARY LIFESTYLE MAY INCREASE YOUR RISK OF DYING
While this report does not relate to breast cancer I thought it would interest readers. A study of 2400 twins in the UK measured the length of the telomeres in their white blood cells. Telomeres are the protective caps on chromosomes which are thought to be a marker of ageing, the shorter the telomeres the more you have aged from a biological point of view. Their length diminishes steadily with age but in some people they shorten faster than in others, indicating premature ageing.
In this study smoking and a high BMI (being overweight) were associated with shorter telomeres while the more leisure time activity participated in, the longer the telomeres. This study provides further evidence for the anti ageing benefits of regular exercise, and exercise is already known to help protect against age-related diseases such as type 2 diabetes, cancer, hypertension, and osteoporosis.
Archives of Internal Medicine 2008
PHASE OF MENSTRUAL CYCLE AND BREAST CANCER SURVIVAL
Some years ago it was suggested that women who had surgery for breast cancer around the time of a menstrual period had a worse outcome, possibly because of the hormonal situation at that time of the month. This set off a lot of research and one of these studies from the UK and Italy has been recently reported.
In this study there were 611 premenopausal women who had not had any oral contraceptive use within the last six months, they were treated by conventional surgery and they were followed for five years. The overall survival of these women was 91% and there was no association between survival and the phase of the menstrual cycle when their surgery was undertaken. It should be noted that virtually all these women had chemotherapy as part of their treatment.
I think it has been reasonably disapproven that the timing of surgery in relation to the menstrual cycle has any bearing on survival from breast cancer.
British Journal of Cancer Jan 2008
Does changing your diet help prevent breast cancer recurrence?
Listed 4 February 2008
Whether making a change to a healthy diet helps with preventing a recurrence in women previously treated from breast cancer has been the subject of much debate recently, largely because there have been two major studies from the United States which have given conflicting results. It is such an important topic, as it is something women could do for themselves to help prevent recurrence from breast cancer, that more work needs to be done to answer this question.
These were two very large trials where women who had previously had breast cancer were randomised to other active encouragement to change their diet, or just given some advice on a healthy diet, and both groups were followed for many years to determine the rate of recurrence in each group. In the first study called WINS (Women's Intervention Nutrition Study), published last year (Journal of the National Cancer Institute 2006) and reported previously in a newsletter, 2437 women were studied with the intervention group actively encouraged to reduce their fat intake but to maintain their calorie intake by increasing intake of fruit and vegetables and protein, and most women in the intervention group successfully achieved this dietary change. After five years the intervention group had a 24% decrease in breast cancer recurrence compared to the control group, an exciting result, and this was particularly so those women with oestrogen receptor negative cancers who had an even greater benefit (> 40% reduction in risk of recurrence). More recently, the other study of dietary change in breast cancer survivors was published (Journal of the American Medical Association 2007), called the WHEL study (Women's Healthy Eating and Living study. In this study 3088 women were randomly assigned to either a major increase in fruit and vegetable and fibre intake and to decrease their dietary fat consumption, or a control group. Again the intervention group achieved and maintained their dietary change, increasing vegetables by 65%, fruit by 25%, fibre by 30%, and decreasing fat by 13%. They were followed for seven years and disappointingly there was no difference between the groups for either breast cancer recurrence or survival.
How come two large and well conducted studies have given such differing results? A possible explanation is that in the first study (WINS) the women in the study group lost weight, although this was not the aim of the study, and on average they dropped more than 2 kg with a decrease in BMI of around 1. Obesity is well recognized as a risk factor for recurrence after breast cancer, and maybe it is body fat which is important, not diet. Another difference is that women in the WINS study reduced fat intake by more than 40% compared to only 13% in the WHEL study where the main aim was to increase fruit and vegetables rather than diminish fat, and maybe it requires a greater fat reduction to reduce breast cancer recurrence. There is currently another diet study in women who have had breast cancer under way in Canada, and hopefully this will help answer these questions?
Aromatase Inhibitors or Tamoxifen for Postmenopausal Women with Oestrogen Receptor Early Breast Cancer
It has long been known that women with oestrogen receptor positive breast cancer who take an anti-oestrogen for some years after having been treated for breast cancer, and the evidence is that five years is preferable although recent studies are suggesting that even longer might be better, have a significant decrease in recurrence and death from breast cancer. The traditional antioestrogen used is tamoxifen and this has been around for more than 30 years, and despite some bad press on occasions, it is a wonderful drug and it is saved hundreds of thousands of lives worldwide over this time. In the last couple of years we have been able to prescribe a new group of antioestrogen drugs called aromatase inhibitors, and these included Letrazole (Femara), Anastrazole (Arimidex) and Exemestane (Aromasin). It should be noted that these aromatase inhibitors only work in women who have been through menopause, unlike tamoxifen which works in both pre-and postmenopausal women.
These new aromatase inhibitors are more effective than tamoxifen at reducing recurrence after breast cancer, with around 20% fewer recurrences compared to tamoxifen, and there is current debate in medical circles as to whether we should be still using tamoxifen, and if so when and in whom. You might say why use tamoxifen at all if aromatase inhibitors are more effective at preventing recurrence, but aromatase inhibitors do have their problems. For a start aromatase inhibitors are very much more expensive than tamoxifen, but patients don't see this as both are now covered by the PBS. Secondly, aromatase inhibitors have side-effects which are different to tamoxifen and which while rarely life-threatening, they can be unpleasant. The most important side effect of aromatase inhibitors is that they can accelerate the development of osteoporosis and women on aromatase inhibitors are known to have more fractures, and this can be serious if it is a hip fracture or a vertebra which is collapsing. Osteoporosis is, however, something which can be monitored and action can be taken to stop the bone loss where necessary. The other occasional side effect is that some women get joint pains and stiffness from aromatase inhibitors, and while this is usually relatively mild, in some people it can be severe. Not a lot can be done to treat these joint pains other than stopping the medication. In one study comparing aromatase inhibitors to tamoxifen, the aromatase inhibitor group had more adverse effects than the tamoxifen group. Both drugs have other side-effects but I have concentrated here on these two main side effects of aromatase inhibitors.
So what do we do, use an aromatase inhibitor or tamoxifen? In general, women with more serious cancers are given an aromatase inhibitor because of the better action in preventing recurrence, while women with lower risk cancers, especially if older and so at higher risk of osteoporosis, are given tamoxifen. Some doctors choose to use an aromatase inhibitor or tamoxifen right from the start and continue to five years, another approach is to start with tamoxifen for 2-3 years then switch to an aromatase inhibitor for another 2-3 years, while a further approach is to use tamoxifen for five years then aromatase inhibitors for another five years (10 years in total). Trials are currently underway to help us determine which is the best approach, but don’t be surprised if you are receiving a different approach to that of your friends - we still haven't got this one sorted out!
Breast Cancer Survival in Australia
Listed 21 January 2008
The Australian Institute of Health and Welfare and the National Breast Cancer Centre have put out a report on breast cancer survival in Australia. This report is based on data provided by state and territory cancer registries, and is for all female invasive breast cancers diagnosed in 1997. In that year there were just over 10,000 new cases of breast cancer diagnosed in Australia, 914 of these being from Western Australia. Relative survival is given as a percentage and compares the survival rate of persons in diagnosed with cancer with the survival rate of the entire Australian population of the same sex and age in the same calendar year. Overall, 85.6% of women diagnosed with breast cancer in 1997 survived five years, and 79.3% survived nine years. I would expect that women diagnosed with breast cancer since 1997 have an even better chance of surviving their breast cancer.
The key findings are:
· Women with small tumours have a much better chance of beating their cancer - 98% five-year survival for women with tumours 10 mm or less compared to 73% five-year survival or women with tumours 30 mm or more. So have your regular breast imaging (mammogram or breast MRI) so that if you are to get a breast cancer, at least find it when it is small.
· Age at diagnosis is related to survival with women less than 40 and more than 70 having a poorer outcome.
· While overall there was no difference in survival for city dwellers compared to rural women, for some reason women with tumours 11-15 mm who lived in the city had a better five-year survival (95%) compared to regional women (five-year survival 88%). I can't explain this one.
· Women from socio-economically advantaged areas have a better survival than those from socio-economically disadvantaged areas (89% five-year survival for the wealthiest areas compared to 84% for the least wealthy areas). They determined socio-economic status by postcode at the time of diagnosis.
Another Study Has Concerns about HRT
Listed 3 December 2008
In the WISDOM study, an Australian, New Zealand and UK study of HRT in women aged 50-69 with menopausal symptoms, women were randomised to either take combined HRT (oestrogen and progesterone), oestrogen alone or placebo. Originally the study was planned to go for five years but it was terminated early after publication of the US Women's Health Initiative study which showed adverse effects from combined HRT, including an increased breast cancer risk, and so the women in the WISDOM study were only followed for around 12 months. The results showed that even after short-term use, compared to placebo, combined HRT had a significant increase risk of cardiovascular events (7 versus 0) and venous thrombo-embolic events (22 versus 3) in the 5600 women studied.
British Medical Journal July 2007
High Testosterone Worsens Survival in Postmenopausal Breast Cancer Patients
Most studies have looked at the effect of oestrogen on breast cancer and it is now quite clear that a high oestrogen level results in an increased risk of recurrence in women previously treated for breast cancer, and so women previously treated for breast cancer should avoid taking oestrogen-based hormone replacement therapy (and this probably includes the ‘natural’ or ‘bio-identical oestrogens’). This Italian study looked at the risk of long-term recurrence in 194 postmenopausal women previously treated for early breast cancer. They had blood taken after their breast cancer surgery for testosterone levels and the women were followed for an average of 14 years. Women with a high testosterone level were twice as likely to get a recurrence of their cancer compared to those with lower levels. Furthermore, these women were also more likely to get another new breast cancer (11 in the high testosterone group compared to 4 in the low testosterone group). While this study does not look at the risk of taking testosterone after breast cancer treatment, just that the natural blood level, it is sometimes prescribed and based on this study it would be wise to avoid using testosterone.
Journal of Clinical Oncology July 2007
Self-Assessment of Breast Cancer Risk
Listed 12 November 2007
The National Breast Cancer Centre has just launched a tool that allows women to determine their breast cancer risk, as well as providing information about what factors contribute to the risk so you can, where possible, make changes your lifestyle to reduce your chances of getting breast cancer. There were 43,000 hits on this website on its first day! It is designed for women over 20 and who have not had invasive breast cancer (but it does allow for in situ breast cancer).
Give it a try at www.nbcc.org.au/risk
MRI and the Other Breast
For most women we don't know what it is that triggers breast cells to become cancers but whatever it is, it tends to affect the breast tissue generally, not just the one spot that has actually developed the cancer. As a consequence it is not uncommon for a woman to have more than one cancer present in her breasts ought to develop another cancer elsewhere in the breasts in the years to come. In fact, studies have shown that around 10% of women will develop cancer in the other breast over the coming years. These do not always show on a clinical examination and mammography, and a recent study which looked at MRI in women recently diagnosed with breast cancer and with a normal clinical examination and mammogram of the other breast, the MRI detected cancer in the other breast in 30 of the 969 women studied (3.1%).
While you might think that this is great and that everyone should have an MRI to check the other breast if they have a cancer diagnosed in one side, there is a downside. For a start in this study 121 of the 969 women had an abnormality found on MRI which needed biopsy, but only 30 turned out to be cancer so a lot of women needed to undergo what turned out to be an unnecessary biopsy. Secondly, having an MRI is not cheap, costing around $500 with no Medicare rebate. Finally, most women want their cancer treated as soon as possible and having an MRI to check the other breast would delay surgery for a week or more and while the cancer is unlikely to change in this time, psychologically it is hard to cope with the wait.
New England Journal of Medicine March 2007
Vitamin D, Calcium and Cancer Risk
While other observational studies have suggested that calcium and vitamin D reduce the risk of developing common cancers, this is the first randomised placebo-controlled trial to be published. 1179 randomly selected women aged more than 55 living in Nebraska, US, were randomly assigned to take by the calcium only, calcium and vitamin D3 (1100 international units daily) or placebo. When men in the calcium and plus vitamin D group had a significant reduction in cancer development, confirming other studies which have suggested this. My only concern is that the numbers in this trial are relatively small.
American Journal of Clinical Nutrition during 2007
Pregnancy after Breast Cancer Treatment
Listed Monday 22 October 2007
A recent study from Western Australia confirmed that getting pregnant after breast cancer treatment is not going to affect survival. In the past there has been some concern that the hormonal changes which occur during pregnancy might result in a higher rate of recurrence for women getting pregnant after having had breast cancer treatment, but this was shown to be false. This new local study of 123 Western Australian women who got pregnant after breast cancer, and more than half were within two years of having had their breast cancer, found that survival might even have been improved by the pregnancy. They had a 92% five-year survival and an 86% 10 year survival, somewhat better than you would expect for the general population of women treated for breast cancer. (British Medical Journal, 2007)
Physical Activity and the Risk of Breast Cancer
There have now been numerous studies which have demonstrated that women who undertake regular physical activity have a lower risk of developing breast cancer. Already this year there have been a couple of new studies published which confirm this.
One study from the United States found that women who did more than six hours per week of strenuous recreational activity had a 23% reduced risk of getting invasive breast cancer compared to those women who did not undertake recreational activity (Cancer Epidemiology Biomarkers and Prevention, 2007).
The other study from Poland looked at lifetime physical activity and found that women with the highest lifetime physical activity had a more than 50% reduction in breast cancer risk, compared to those with the lowest level of activity. This study also found that the earlier a woman started physical activity the better, with the most risk reduction being for those who started at less than 20 years of age (Cancer Detection and Prevention, 2007).
Breast Density and Breast Cancer Risk, and the Detection of Breast Cancer
While mammograms are useful in detecting breast cancer, they are far from perfect in this job. One of the main reasons why mammograms miss cancers is that in some women their breast tissue is very dense and so the shadow we look for from the breast cancer can be hidden amongst the dense but normal breast tissue. Calcifications will show on a mammogram, even in dense breasts, but only a relatively small proportion of breast cancers have these tell-tale calcifications in them. The density is just fibrous and glandular tissue, a normal part of a young woman's breasts, and as we get older it undergoes a process called involution, especially after having children. With involution the dense fibroglandular tissue gets replaced by fatty tissue and fat is of low density, and it is relatively easy to detect a cancer in breasts which have undergone extensive involution. It is, however, a very variable process with some women's breasts having involuted in their 30s, and in others they stay dense until well into the 70s.
A recent study from Canada confirmed what we have already suspected, that about half of all cancers missed in a screening mammogram could be attributed to dense breast tissue hiding the cancer (although not studied in this particular research, and for the information of readers, the reason the other 50% would have been missed include things like the cancer being too small to be seen at the time of the mammogram, some cancers such as lobular cancers do not show well in a mammogram due to their growth pattern, and yes, occasionally human error, hence the research for computer assistance to help with diagnosis - see elsewhere in this newsletter).
The research also found that women with dense breasts not only were more likely to have the cancer missed, but they were at much higher risk of developing breast cancer in the first place, and this was around a five times increase in risk (500%). This is an enormous risk increase, much the same as having your mother as well as a couple of other relatives having had breast cancer! Women with dense breasts should at minimum have an ultrasound at the same time as the mammogram, and while this has not really been proven to be of benefit, I know from practice that an ultrasound will occasionally find a cancer in the dense breast when it is not seen in the mammogram, or preferably have an annual breast MRI (again see elsewhere in this newsletter). Even women with dense breast should still have an occasional mammogram as mammograms in women with dense breasts will still detect calcifications (New England Journal of Medicine, January 2007).
Stress and Breast Cancer
Listed Monday 1 October 2007
A review of the relationship between stress and breast cancer was recently published in Nature Clinical Practice-Oncology (November 2006). This is a difficult subject and there has been a vast amount of research into psychological stress and the risk of breast cancer. It is also something high in the minds of women diagnosed with breast cancer . How often am I asked: “I have had a very stressful few years. Do you think this may have had something to do with why I have got breast cancer?” Psychological stress can affect the immune and hormonal systems, and so there is potential for an effect on risk, but previous studies have produced conflicting results. This review looks at the subject again, and in particular it looks at the role of stress in causing a breast cancer, and also at how it might affect recurrence after previously treated breast cancer. One of the problems with previous studies is that many have been retrospective ie: a woman diagnosed with breast cancer is asked to recall stressful events in her life. Such an approach is open to bias as a woman in this situation is more likely to be looking for reasons as to why she developed breast cancer, and so is more likely to remember things which may be regarded as not important to the control subject who has not had breast cancer. This review only looked at prospective studies, not retrospective studies. To complicate the subject, different people handle stressful events differently, and this is difficult to measure ie: there are differences in coping capabilities. Yet another complicating factor is that most studies look at major events, such as a death or separation, as these are easy to record objectively. Work or home related stress can be a continual event and is more difficult to quantify.
Thirty five studies addressing the association between stress and breast cancer were identified from the medical literature, but only 18 were considered suitable (13 in relation to incidence and five on relapse) as the others were either retrospective studies or had a poor study design. Of the 13 studies which looked at stress as a cause for breast cancer, most showed no association while two studies did show a positive association, and two a negative association. One of the studies having a positive association was a large Finnish study of 10,808 twins followed for 15 years, and with such a large study any findings are likely to be valid. This study demonstrated a 15-35% increase in breast cancer risk with an additional stressful life event. The studies which found a negative association were both from Denmark, one of these finding that the death of a husband reduced breast cancer risk! Of the five studies looking at associations between stress and risk of recurrence, the results were again mixed with two showing a positive association, one a negative association, and two no difference.
Overall the results are inconsistent and it is difficult to draw conclusions, but it would appear to be unlikely that stress is a major contributor to either the cause or recurrence from breast cancer.
Soy Intake and Breast Cancer
There has been quite a bit in the press recently warning against using soy products if you have had breast cancer, as the components of soy have a weak oestrogen-like activity on breast cells. Personally, I think these fears are unfounded as this information was only based on what happens if you put soy into a test tube with breast cells, and there is no evidence of any adverse effect in animal experiments, nor in human studies. The body is much more complex than just being a collection of cells and it is likely that a test-tube experiment has little relevance to how soy affects the whole body, and the vast bulk of research would indicate that it is either harmless or beneficial as regards breast cancer. Furthermore, the reports in the press have suggested that soy might counteract the effect of antioestrogens used in breast cancer treatment, such as tamoxifen. This view has been disproved by a recent study of more than 1277 women, 380 of whom were taking tamoxifen. The results showed that the levels of tamoxifen in the body were not affected by soy consumption. Interestingly, they did find that tamoxifen levels were lower in premenopausal women, women with a high body mass index (BMI), and they were higher in women who were taking blood pressure medication (Journal of Clinical Oncology, 2007).
Meat and Breast Cancer
Listed Monday 17 September 2007
The Archives of Internal Medicine recently reported that women who ate an average 1.5 servings of meat each day are almost twice as likely to develop breast cancer as women who eat meat 3 times each week or less. This was an observational study (The Nurses Health Study in the US) rather than a randomised trial, where more than 90,000 women aged 26-46 at enrolment in 1991 filled out questionnaires about their diet. They were followed for 12 years and those women who ate more red meat were more likely to develop hormone dependent breast cancers (oestrogen receptor positive). While this is not a conclusive study (only randomised trials are really conclusive), it is an indication that meat consumption should be curbed.
CAD Improves Cancer Detection in Mammograms
Computer-Assisted Diagnosis (CAD) has been shown in a recent study (American Journal of Roentgenology, 2006) to improve the cancer detection rate compared to radiologist-alone detection of breast cancer in mammograms. In CAD, computer programs have been written to pick out features in a mammogram which might be cancerous. Over two years almost 10,000 women were assessed by either radiologist- alone or radiologist plus CAD. Of the 104 cancers found in these mammograms, 10 were found only by the computer, thus improving the overall accuracy over that which would be achieved by radiologist reporting alone by around 10%. Furthermore, these CAD detected cancers were smaller.
Managing Menopausal Symptoms
More on managing the menopause. As reported elsewhere in this newsletter, women who have had breast cancer should not use oestrogen based HRT as this has been proven to increase the chances of the cancer recurring. What are the alternatives for women with troublesome menopausal symptoms? Unfortunately there are few effective treatments and a recent review in the New England Journal of Medicine (30th of November 2006) went through the possibilities. Menopausal symptoms include hot flushes and in particular night sweats, vaginal dryness, urinary incontinence, difficulty sleeping, mood swings, fatigue, weight gain, memory loss, etc. The main symptom is flushes which occur in 65% of women at this time of life, and they are worse in cigarette smokers, women with a high alcohol consumption, and obesity. They are less common in women of Chinese and Japanese origin. In 85-90% of women in the flushes settle within 4-5 years, but 10-15% continue long-term. Because the symptoms generally improve with time, many treatments are often reported to be beneficial but when tested in a properly randomised controlled trial they prove to be no better than placebo. This review reported that:
- Oestrogens reduce hot flushes by 80-95%, and often low doses are effective. However, oestrogen based HRT increases the chances of having a stroke by 40%, and also of heart attacks and blood clots, although trans-dermal applications (patches) have a lower risk of these vascular side-effects. For women who have not had breast cancer, while combined oestrogen and progesterone HRT is associated with an increased breast cancer risk after only five years, for oestrogen-only HRT (progesterone is not necessary for women who have had a hysterectomy) the risk is much lower and it can be safely used for at least 10 years, although the dose should be kept to the minimum necessary to control symptoms.
- Behavioural and Natural Therapies. Trials of acupuncture, yoga, dong quai, Chinese herbs, evening primrose oil, ginseng, kava and red clover extract have not been shown to help. Elsewhere in this newsletter Black Cohosh (Remifemin) and soya have also been proven to be ineffective compared to placebo.
Non-oestrogen hormones:
At high doses progestogens are effective at reducing hot flushes but they commonly have side-effects and so are not popular. Tibolone (Evista) is quite effective but its safety is still being evaluated.
SSRI Antidepressants:
The effectiveness of these has varied in trials, but where effective initially, the benefit rarely persists for long. Furthermore, side-effects are common.
Gabapentin: This is moderately effective in trials but again has side-effects.
Clonidine: This has little benefit in trials and also has unpleasant side-effects.
Overall, you can see that there is little that is both effective and safe! We wait with interest the results of the tibolone trial, for this is quite effective and if proven by the trial to be safe, it would be a real blessing. Vaginal symptoms are very effectively treated by local oestrogens (creams, or tablets such as Vagifem), and generally only a little gets into the circulation and so they are considered safe. Nevertheless, the dose should be kept to the minimum necessary to reduce symptoms. In one trial an over-the-counter vaginal moisturiser (Replens) was just as effective as vaginal oestrogens.
San Antonio Breast Cancer Symposium (SABCS)
Listed Monday 3 September 2007
The SABCS is probably the biggest and best breast cancer conference and it is held each year in San Antonio, Texas, just before Christmas. I had the privilege of attending this year. More than 8000 doctors, researchers and other health professionals attended from 54 countries. Some of the highlights at the conference included:
Biology and New Drugs for Breast Cancer. Several lectures by breast cancer researchers explained how by getting a detailed understanding of breast cancer biology - how cancer works and grows - we can specially design drugs to destroy cancer cells. There are dozens, or maybe even hundreds, of new drugs under development. For the most part these work directly on cancer cells and their immediate environment, rather than the whole body effects of chemotherapy, and so tend to have fewer side effects. These drugs have started to appear in the market, the first being Herceptin which was released this year for early breast cancer and with others such as Avastin and Tykerb in the final stages of testing and soon to become available, but many more will follow over the coming years and chemotherapy will one day only be used as a last resort.
Breast Cancer Vaccine. A paper was presented showing for the first time that a breast cancer vaccine might be possible. Until now a breast cancer vaccine has been very elusive, unlike cervical cancer where a vaccine has now been released and it is anticipated that it will largely eliminate cervical cancer in the coming decade or so. It is still early days for breast cancer but it looks promising.
Prevention. Quite a lot of time was devoted at the conference to the prevention of breast cancer. It was pointed out that for premenopausal women who take tamoxifen for five years, they will almost halve the chances of developing breast cancer and this effect will last for many years after finishing the five-year course of treatment. It was also pointed out that a woman probably only needs one quarter of the current dose of tamoxifen to achieve a preventive effect ie: 5 mg a day instead of 20 mg a day, and for premenopausal women there is no increase in the risk of thrombosis or uterine cancer, things which can be a problem when taking tamoxifen after menopause. For postmenopausal women, raloxifene (Evista) is a better alternative as it does not have the problems with thrombosis and uterine cancer as mentioned above, and it also helps prevent osteoporosis. Raloxifene should reduce breast cancer risk by half with five years of therapy, and this benefit will again last for a decade or more after cessation of the tablets. New prevention studies are underway looking at the aromatase inhibitor drugs (Arimidex, Femara and Exemestane), and it is likely that these will be still more effective. They are, however, only useful after menopause and I am concerned that their side effects such as osteoporosis and joint pains will prevent them being used widely. It was pointed out that a considerable proportion of the population take a cholesterol lowering tablets each day (statins) to reduce the chances of getting heart disease - why not a tablet each day to prevent breast cancer? Premenopausal women at increased of risk of breast cancer should seriously consider five years of tamoxifen, and postmenopausal women at increased risk should seriously consider taking raloxifene. (One problem is that neither of these are subsidised by the PBS for use as breast cancer preventing agents, and so it may be necessary to pay the full cost of the drug, and this understandably is a significant disincentive).
Reducing Dietary Fat Helps Prevent Recurrence. This trial is the first randomised controlled trial to show that by reducing fat intake it is possible to help prevent recurrence in women who have had breast cancer. 2437 women were randomised between 1997 and 2001 to either a reduced fat intake or continuing on their current diet, and they were followed subsequently and recurrences reported. Those who were in the fat reduction group had a 24% lower chance of getting a recurrence of their breast cancer, and it was found that this is even greater for women with hormone insensitive tumours (oestrogen and progesterone receptor negative breast cancers). In essence, dietary fat reduction after breast cancer is probably more effective than chemotherapy in preventing recurrence for women who have had hormone receptor negative cancers! (But this should be done in addition to chemotherapy, not instead of it).
Breast Screening Guide for Young Women
Listed Monday August 20, 2007
While the government promotes screening mammograms in women 50 or older, breast cancer is still a common disease in younger women. 6% of breast cancer cases occur at age less than 40 and 27% occur at age less than 50 (in Western Australia in 2005 there were 66 cases of breast cancer at age less than 40 and 314 cases aged less than 50). Younger women need to be aware that breast cancer can occur at any age but while awareness is important, mammographic screening is not so effective in younger women, and so with the fewer cases and less effective mammographic detection, the government has rightly only promoted mammographic screening in older women.
So what can younger women do? Breast self examination, regular GP checks and ultrasound all help to some extent in younger women but are not really very effective at finding breast cancers at the early stage necessary to improve survival. MRI is now being recognised as being much more accurate than mammography in young women, and furthermore there is no painful compression and no x-rays involved. A problem, however, is that there has been no rebate under Medicare but it was recently announced by the Minister for Health (Commonwealth government) that a rebate will be introduced in the near future. It is known that there will be restrictions on who can have breast MRI under Medicare and while the details have not yet been published, it is expected it will be restricted to young women at high risk on account of their family history or known to have a genetic mutation which puts them at high risk for breast cancer. Breast MRI’s are available now for all women, but you have to pay (about $500), with no rebate from Medicare.
New guidelines to be published soon will recommend that younger women in high-risk categories should undergo regular breast MRI. (Australian Radiology 2007)
Lavender and Tea Tree Oils
Listed Monday August 20, 2007
A recent report linked the use of lavender and tea tree oils to three cases of gynaecomastia in boys (gynaecomastia is the development of breasts in males, a relatively common and transient phenomenon in boys and young men). The lavender and tea tree oils were used regularly by these boys in soaps, lotions and hair styling gels. Subsequent studies in human breast cell cultures confirmed that lavender and tea tree oils have weak oestrogen and androgen activities, and perhaps cause hormonal imbalance. This information begs the question of their use in women who have had breast cancer, where the use of oestrogen is known to increase the risk of recurrence.
Dr David Ingram
Specialist in Diseases of the Breast
Suite 7
Mount Medical Centre
140 Mounts Bay Road
Perth WA 6005
T - 08 9321 1620
Neither the Breast Cancer Foundation of Western Australia, nor any of their employees or associates, assumes any legal liability for the accuracy, completeness, or usefulness of any information from this website or from information from the links to other websites. The opinions expressed in this website are those of the author. This information is intended for general discussion only and should not be relied upon. Advice given on issues is not intended as medical advice. We suggest all persons seek independent medical advice.