Survival Outcomes After Contralateral Prophylactic Mastectomy

A Decision Analysis

Portschy, Pamela R.
Kuntz, Karen M.
Tuttle, Todd M.

Affiliations of authors: Department of Surgery (PRP, TMT) and Division of Health Policy and Management (KMK), University of Minnesota, Minneapolis, MN.

Correspondence to: Todd M. Tuttle, MD, MS, University of Minnesota Department of Surgery, 420 Delaware St, Mayo Mail Code 195, Minneapolis, MN 55455 (e-mail: [email protected]).

Received August 1, 2013

Received in revised form April 29, 2014

Accepted May 12, 2014

Journal of the National Cancer Institute 106(8), August 2014. | DOI: 10.1093/jnci/dju160

Background

Contralateral prophylactic mastectomy (CPM) rates have substantially increased in recent years and may reflect an exaggerated perceived benefit from the procedure. The objective of this study was to evaluate the magnitude of the survival benefit of CPM for women with unilateral breast cancer.

Methods

We developed a Markov model to simulate survival outcomes after CPM and no CPM among women with stage I or II breast cancer without a BRCA mutation. Probabilities for developing contralateral breast cancer (CBC), dying from CBC, dying from primary breast cancer, and age-specific mortality rates were estimated from published studies. We estimated life expectancy (LE) gain, 20-year overall survival, and disease-free survival with each intervention strategy among cohorts of women defined by age, estrogen receptor (ER) status, and stage of cancer.

Results

Predicted LE gain from CPM ranged from 0.13 to 0.59 years for women with stage I breast cancer and 0.08 to 0.29 years for those with stage II breast cancer. Absolute 20-year survival differences ranged from 0.56% to 0.94% for women with stage I breast cancer and 0.36% to 0.61% for women with stage II breast cancer. CPM was more beneficial among younger women, stage I, and ER-negative breast cancer. Sensitivity analyses yielded a maximum 20-year survival difference with CPM of only 1.45%.

Conclusions

The absolute 20-year survival benefit from CPM was less than 1% among all age, ER status, and cancer stage groups. Estimates of LE gains and survival differences derived from decision models may provide more realistic expectations of CPM.