European Journal of Cancer
Issue 6, 2010

By Helen Saul

Survival benefit after contralateral mastectomy

Contralateral prophylactic mastectomy (CPM) was associated with a small improvement in 5 year survival from breast cancer, US researchers say. The effect was seen mainly in young women with early-stage, oestrogen receptor (ER) negative disease.

Researchers used the Surveillance, Epidemiology, and End Results database to identify 107,106 women with breast cancer who had undergone mastectomy between 1998 and 2003. A subset of 8902 women had also undergone CPM.

CPM was associated with improved disease-specific survival (hazard ratio of death was 0.63). The association was due to a reduction in deaths among women aged 18-49 years with stage I-II ER-negative cancer: 5 year-adjusted breast cancer survival for this group was 88.5% with CPM versus 83.7% without (J Natl Cancer Inst 2010; 102:1-9)

Lead author Dr Isabelle Bedrosian (University of Texas MD Anderson Cancer Center, USA) said that growing numbers of breast cancer patients are opting for CPM. “Across the breast cancer community, studies have shown that the utilisation of the procedure is skyrocketing.

“Until now, we’ve counselled these patients on a very important, personal decision in a vacuum. With our study, our goal was to understand the implications of the surgery and who may benefit.”

Although a causal relationship between survival and CPM was not proven in this study, the researchers said they expect that the survival benefit will increase with longer follow-up.

“Our research found that breast cancer patients over the age of 60 can be reassured that they will not benefit from CPM,” Bedrosian said. Among other populations of women – such as those aged between 50 and 60; or among young women with early stage, ER-positive breast cancer who receive tamoxifen for only 5 years – the findings about CPM are less clear.

“For some additional breast cancer patients, CPM may very well be a medically-appropriate option,” she said.