What about the other breast?
More women are having their unaffected breast removed to prevent the return of cancer. But are these extra surgeries really preventing anything?
Over the last 20 years the number of preventative breast cancer surgeries has increased; surgeries intended to reduce a woman’s risk of getting the disease. Some call this the Angelina Jolie effect, referring to the actress who had both her breasts removed when she found out she had the dangerous BRCA1 gene mutation.
But these surgeries are becoming more common in women who don’t have dangerous gene mutations. Most have been diagnosed with breast cancer and are getting the unaffected breast removed, as well as the one with the tumour. But are these surgeries actually preventing anything? And do the negative effects of the surgery outweigh the benefits?
When doctors find a breast tumour, and follow-up tests show that it’s cancerous, most patients are recommended a surgical option by their doctor: a lumpectomy, if the tumour is small (a procedure in which the tumour is taken out, and the rest of the breast is conserved), or a unilateral mastectomy, if the tumour is large (where the breast with the tumour is removed, but the other breast is left untouched).
Some women choose an additional option: to remove both breasts - the breast with the tumour, and the other breast, to decrease the chance of another tumour forming. This removal of the unaffected breast is called a contralateral prophylactic mastectomy (CPM).
A new study of almost 500,000 American breast cancer patients showed that between 1998 and 2010, the number of patients opting for a CPM rose from 3.9% to 12.7%.
Similar patterns are being seen here in New Zealand. With data collected for the Breast Cancer Registers, we’ve seen an increase in women opting for this procedure, from 0.6% in 2000 to 4.9% in 2010.
It’s easy to understand why patients are choosing this option. No one wants to go through cancer twice. Even though the surgery is more extensive, carries higher risks, and is harder to recover from, patients want both breasts removed, so that this never happens again.
But preventing the return of cancer isn’t that simple. The main threat is from metastasis, which is when cells from the original cancer spread to different parts of the body and start growing into new tumours. As long as the first surgery is successful, whether it’s a lumpectomy or mastectomy, the risk of metastasis stays at around 12%, regardless of whether or not the second breast is removed.
By comparison, the risk of developing a tumour in the opposite breast, the kind of cancer a CPM is protecting against, is very low, at only 0.5% (or 1 in 200). The risk is so low, in fact, that doctors say CPMs have ‘no survival benefit’.
The exception to this rule is patients with BRCA mutations, or other genetic defects that carry an increased breast cancer risk. These women already have a much higher cancer risk than people in the general population – up to 80% likelihood of developing the disease. Having a preventative double mastectomy might be the smart thing to do.
The rise of women opting for CPMs in New Zealand might come down to doctor-patient conversations. Do patients opt for these extensive surgeries because no one tells them there is very little survival benefit? Or do they fully understand the risks, and still want the peace of mind a CPM will give them?
Given that research has shown that CPMs don’t increase your chance of survival (unless you have a specific genetic mutation), would you still opt for the extra surgery? Is a riskier surgery and a longer recovery time just a small price to pay for peace of mind?