For Average Risk of Second Breast Cancer, Preventive Breast Removal Yields Slight Benefit
Life expectancy improves only slightly for women with cancer in one breast who choose to remove the healthy breast along with the affected one, a recent study shows.
The research looked at women with an average risk of developing a second breast cancer in the opposite breast. It did not include women with BRCA gene mutations who have a higher risk of developing a new breast cancer.
More and more U.S. women who have one breast removed for breast cancer treatment are also choosing to have the other, healthy breast removed. This type of surgery is called contralateral prophylactic mastectomy, or CPM.
Studies show most women choosing CPM are concerned about developing a new cancer in the healthy breast. Yet some may overestimate their risk.
While CPM can lower risk of a second primary breast cancer, not spread or metastasis, by about 90 percent for people at high risk, for most women, the risk is already low. And, taking hormonal therapies like tamoxifen and aromatase inhibitors lowers the existing risk for women with hormone receptor-positive disease, the most often diagnosed hormonal type.
The study measured whether CPM lengthened life for women who had cancer in one breast. The researchers wanted to estimate survival time to help women and doctors decide whether CPM was needed to live longer.
Using past data from studies, registries and databases, the researchers developed a system to predict how long a woman would live after having CPM. They used the same system to predict survival for women who had radiation therapy and only the tumor removed, or only one breast removed. They collected information on age at diagnosis, disease stage and whether the disease was hormone receptor-positive or -negative. All women had stage I or II disease.
Overall, the team predicted CPM extended life by 1 to 7 months.
It seemed more useful, resulting in closer to 7 months additional survival, for women who
- were age 40 or younger when diagnosed, so have a longer life expectancy
- had stage I breast cancer, which is easier to treat and recover from, leading to a longer life expectancy
- had estrogen receptor-negative breast cancer, which is more likely to develop a second time
After 20 years, no group had a greater than 1 percent difference in survival.
This study looked only at survival data. It did not include quality of life factors, which can vary widely for individuals.
What This Means For You
If you have breast cancer in only one breast, it’s understandable that you may worry a new cancer may develop in the opposite breast. Choosing to have both breasts removed may make you feel you’re taking action against future cancer.
This study shows that CPM may only extend life by a short length of time for women at average risk of a second cancer. This means that you may be able to have only the affected breast removed and see the same results.
Women at higher risk due to genetics or family history are more likely to have a second cancer and can benefit more from CPM.
If you feel anxious about a second breast cancer forming or the effects of having extensive surgery, talk with your doctor. He or she can help you understand your risks and treatment choices. Take the time you need to take in information and ask questions.
Portschy, PR, Kuntz, KM, Tuttle, TM. Survival Outcomes After Contralateral Prophylactic Mastectomy: A Decision Analysis. Natl Cancer Inst. 2014; doi: 10.1093/jnci/dju160.
This article was supported by Cooperative Agreement Number DP11-1111 from The Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention.