NIPPLE SPARING PROPHYLACTIC MASTECTOMY

Nipple-sparing mastectomy (NSM) appears to be a safe option for women seeking to reduce their risk of developing breast cancer, according to a new report.

It comes from the Comprehensive Breast Cancer Program at the Cleveland Clinic, Ohio, which was the first center in the United States to report on NSM in 2004.

For the past 15 years, NSM has been used for selected patients undergoing treatment for breast cancer and for those seeking prophylactic mastectomies because of a high risk of cancer.

Most studies of NSM have focused on patients with breast cancer, and while there have been reports on the use of bilateral NSM for breast cancer risk reduction, those have focused only on patients with BRCA1/2 mutations and many reported only short-term data.

The new study from the Cleveland Clinic reports longer-term oncologic outcomes.

The study was published online March 28 in the British Journal of Surgery.

From 2001 to 2017, 272 bilateral NSMs were performed on 136 patients (135 women and one man) with a median age of 41 years. The mean follow-up was 53 months and none of the patients developed breast cancer.

"Our study adds to the existing evidence regarding the safety of NSM for breast cancer risk reduction, and it's an important study because of the large number of patients and long follow-up," said lead author Stephen R. Grobmyer, MD, director of Breast Services at the Cleveland Clinic.

Notably, the study showed none of the women developed breast cancer following the procedure.

"The study is also important because we report a series of patients with other genetic mutations who have undergone NSM for breast cancer risk reduction," Grobmyer explained. "Genetics is increasingly being incorporated into the care of breast cancer patients."

No Cancers Long Term

In the current study, Grobmyer and colleagues evaluated trends in patient characteristics, indications for surgery, and long-term outcomes of bilateral NSM for breast cancer risk reduction over time.

All participants underwent risk-reducing bilateral NSM between October 2001 and May 2017. The most common indication for undergoing the procedure was a mutation in a breast cancer-associated gene (104 patients, 76.5%): BRCA1, 62 patients (45.6%); BRCA2, 35 (25.7%); PTEN, 2 (1.5%); TP53, 3 (2.2%); and ATM, 2 (1.5%).

Other indications included a strong family history of breast cancer (n = 19, 14%), lobular carcinoma in situ/atypia (n = 10, 7.4%), and a history of mantle field irradiation (n = 3, 2.2%).

The proportion of women who sought a risk-reducing bilateral NSM for mutation in a breast cancer-associated gene significantly increased from 2001 to 2005, and the procedure was first performed for BRCA in 2004, PTEN and TP53 in 2013, and ATM in 2015.

Mean duration of follow-up was 53 months, median follow-up was 38 months, and 61 patients were followed for more than 4 years.

"We do plan to continue to follow these women to add further to the long-term safely of NSM," explained Grobmyer.

"We think bilateral NSM is an option in women for risk reduction in patients at significantly elevated risk for breast cancer and should be discussed with patients," he commented.

Other options include chemoprevention for some patients and increased surveillance for others, he added. "The decision regarding breast cancer risk reduction strategies should be made after careful discussion of the options with a patient's caregivers."

The authors have reported no relevant financial relationships.

BJS Open. Published online March 25, 2019. Full text

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