Worry May Drive Decision for Preventive Double Mastectomy

Breast cancer patients often had both breasts removed when it may not have been necessary

(RxWiki News) More and more women are choosing to get both breasts removed after being diagnosed with cancer in one breast. Now, there is concern that these decisions may be more based on fear than actual medical risk.

A recent study found that about three quarters of women who had both breasts surgically removed following a breast cancer diagnosis in only one breast were at very low risk for having cancer in the unaffected breast.

The researchers discovered that many women based their decision to have both breasts removed because they worried about the cancer coming back, despite the fact that there often were no clinical reasons for the surgery.

"Talk to your oncologist about the risks and benefits of having both breasts removed."

The lead author of this study was Sarah T. Hawley, PhD, MPH, from the Department of Internal Medicine at the University of Michigan Medical School and the Veteran Affairs Healthcare System in Ann Arbor, Michigan.

The study included 1,447 newly diagnosed breast cancer patients who were identified though the Detroit and Los Angeles Surveillance, Epidemiology, and End Results (SEER) registries between June 1, 2005 and February 1, 2007.

The women were between the ages of 25 and 79 years old at the time of diagnosis, and their average age was 59 years.

Of these women, 47 percent were white, 57 percent were married, and 59 percent had at least some college level education.

None of the participants had their cancer come back.

Doctors may advise women with a family history of breast or ovarian cancer, or who are genetically prone to breast cancer, to strongly consider having both breasts removed when only one breast is affected because they have an increased risk cancer developing in the other breast.

However, Dr. Hawley and colleagues explained that these women represent only about 10 percent of all women diagnosed with breast cancer. Women without a family history or genetic mutation are very unlikely to develop a second cancer in the unaffected breast.

The SEER data showed whether the women in this study had undergone one of three types of surgery for breast cancer:

  • Unilateral mastectomy (surgical removal of one breast)
  • Breast conservation surgery (surgical removal of the cancerous cells in the breast but not the whole breast)
  • Contralateral prophylactic mastectomy (surgical removal of both breasts for preventive reasons when only one breast has been diagnosed with cancer)

Contralateral prophylactic mastectomy (CPM) is a bigger operation than the other two surgeries. As a result, it's more expensive, carries the potential for more complications, and has a longer and more difficult recovery.

Dr. Hawley and team also looked at which factors were associated with the decision to have surgery.

These researchers found that 34 percent of the women underwent unilateral mastectomy, 78 percent underwent breast conservation surgery, and 8 percent underwent CPM. They also found that 19 percent of the women had strongly considered CPM.

Out of those who strongly considered CPM, 32 percent received the surgery, 46 percent underwent unilateral mastectomy, and 23 percent underwent breast conservation surgery.

The researchers discovered that 69 percent of all the women who underwent CPM did not test positive for any major genetic or familial risk factors for developing breast cancer in the other breast after one had already been diagnosed.

The women who underwent CPM were about 10 times more likely to have received genetic testing, with either positive or negative results, compared to those who had a unilateral mastectomy, and almost 20 times more likely than those who had breast conservation surgery.

Compared to the women who underwent unilateral mastectomy or breast conservation surgery, the women who chose CPM were 5.19 times and 4.24 times more likely to have a strong family history of breast or ovarian cancer.

The women who underwent CPM were twice as likely to have had an MRI at the time of diagnosis than the women who underwent unilateral mastectomy or breast conservation surgery.

College-educated women were about five times more likely to undergo CPM than either of the other two surgeries.

Lastly, the women who reported worrying a lot about their cancer coming back were 2.81 times more likely to undergo CPM versus unilateral mastectomy and 4.24 times more likely to undergo CPM compared to breast conservation surgery.

These findings suggested that fear of the cancer coming back was a large driving force behind the women deciding to undergo CPM, even when they did not necessarily have a clinical reason for it, and that many of them would have been good candidates for the other two surgeries.

"Women appear to be using worry over cancer recurrence to choose contralateral prophylactic mastectomy. This does not make sense, because having a non-affected breast removed will not reduce the risk of recurrence in the affected breast," Dr. Hawley said in a press statement.

The researchers concluded that not only do women need to be better educated about the risks and benefits of CPM, but surgeons also should be aware of how much their patients’ worries about the cancer coming back can affect their surgery choice.

This study was limited because data only came from two urban areas in the United States, and therefore the findings are most likely not generalizable to other areas. Also, data came from self-reports from the women, and the researchers had no way of knowing whether any of the women who underwent CPM actually had cancer in both breasts.

The researchers did not have data about the women’s history of radiotherapy or whether the decision to undergo CPM had anything to do with wanting to have both breasts reconstructed. Finally, some women dropped out between the beginning of the study and follow-up.

This study was published on May 21 in JAMA Surgery.

The National Institutes of Health provided funding.

Review Date: 
May 21, 2014