Being diagnosed with breast cancer and undergoing mastectomy can be a traumatic experience, and surgeons are often consulted about “prophylactic” mastectomy – a procedure to remove the healthy breast along with the cancer-affected breast in the hope of avoiding a recurrence of breast cancer at a later stage.

Researchers at the University of Minnesota have found that the “survival benefit” for this procedure is less than 1% at 20 years post-surgery – at least, for patients who do not have the BRCA gene mutation.  According to Medscape, their findings were presented recently at the American College of Surgeons 2013 Annual Clinical Congress.

The increasing demand for the procedure is surprising in itself, given that not so long ago most patients dreaded the removal of a breast and would not wish to consider the loss of both breasts if one, at least, was healthy. Now, it seems that as many as one in five women are undergoing double mastectomies despite having a normal lifetime risk and a healthy other breast. What has changed? It’s not entirely clear but may have to do with the increasing recognition and awareness of breast cancer in society as well as publicity around public figures who opt to have prophylactic mastectomies earlier in 2013. Film star Angelina Jolie is a case in point, whose life chances have been substantially improved because she was found to have the BRCA mutation after two close female relatives developed breast cancer. In cases like Angelina’s, prophylactic mastectomy is worthwhile, even though no cancer has yet been diagnosed.

Women are also aware that surgical management of the breast has improved dramatically in the past couple of decades and that cosmetic outcomes are often very acceptable with modern reconstruction techniques.

However, the new computer model which predicts the likelihood of long term survival of patients who have had breast cancer but do not have the high-risk BRCA mutation suggests that for most patients there is little to be gained in terms of risk reduction, by removing the healthy breast.

The research compared risks for breast cancer occurring in the other breast, and chances of survival with and without prophylactic mastectomy, in women aged between 40 and 60 who had been diagnosed with early-stage breast cancer but were without the BRCA mutation. The analysis also took into account age, how much the original breast tumour had grown before diagnosis (Stage I or II), and also the extent of oestrogen receptor involvement.

According to this model, a person at the lowest risk for recurrence of breast cancer (i.e. younger, with a Stage I tumour, and oestrogen-receptor negative), might hope (on average) to gain an approximate extra 6 months of life. An older patient with a more developed and/or oestrogen-receptor positive tumour might gain one extra month by undergoing precautionary removal of the healthy breast. The absolute overall difference in survival at 20 years ranged from 0.36% to 0.94% for the 2 patient groups.

Dr Isabelle Bedrosian of the University of Texas gives the following reasons not to have a prophylactic mastectomy:

  • the risk of cancer occurring in the other breast is already quite low,
  • there are other options to reduce the risk (aside from surgery),
  • and in most cases, your risk of dying from something other than breast cancer far exceeds the breast cancer risk

In other words, there are better things you could be doing for your health if your goal is to live a long and healthy life.

It may be that if you have a raised breast cancer risk (see our article on knowing your risk), the benefit of prophylactic mastectomy might outweigh the costs. For a woman recently diagnosed with cancer and faced with decisions about surgery, time is a luxury she does not have (unlike the woman who knows she has the BRCA but as yet does not have cancer). Under such circumstances, people tend to base their decisions on feelings, and also to over-estimate their future risk of breast cancer which according to expert is not likely to be more than 5%.

Meanwhile, a woman newly diagnosed with breast cancer feels vulnerable and want to do anything possible to protect herself from further cancer – a situation in which a rational review of the data is in any case difficult and also is unlikely to achieve much in terms of resolving those strong feelings.

Dr Bedrosian confirmed to Medscape that even though she does point out to her patients that there’s really no need to go through the double mastectomy, many of them still want to and where possible the patient’s choice is respected – as this is the best way to help her move forward in terms of cancer treatment and of her life generally.

The key here, as so often in medical care, is “informed consent”. In order to make the best choice, a woman needs to know what the surgery involves, how much more difficult it may be for her to recover fully after double mastectomy, and what the potential costs and benefits may be. Here in South Africa, we may also have to factor in the decisions of Medical Aid companies who also read the research and constantly review their guidelines regarding allowable benefits.

Dr Bedrosian would like to see better tools in the hands of doctors and of women with breast cancer, such as structured “decision aids” which help the individual follow a logical process to a conclusion that she feels she can trust. In this way, we can hope for a situation where women are in a position to make the best choices for their own health, based not only on awareness of the reality of breast cancer, but also on the available research data.

Reference:

Miriam E. Tucker, “Prophylactic Mastectomy Offers Minimal Gain in Breast Cancer”. October 08, 2013
http://www.medscape.com/viewarticle/812261