By Monica J. Smith

Chicago—Recent research suggests that more women can safely undergo nipple-sparing mastectomy (NSM), especially as surgeons become increasingly proficient in the procedure. The absolute contraindications for NSM are generally agreed upon, but additional selection criteria are less clear and vary from one institution to another.

Suzanne Coopey, MD, assistant in surgery, Massachusetts General Hospital, Boston, and her colleagues analyzed data on all patients at their institution who underwent NSM between January 2007 and 2012. “We began performing NSM at Massachusetts General in 2007. As experience was gained, we found that eligibility for the procedure was extended to patients who were initially excluded,” Dr. Coopey said.

“In 2007, only 1% of all mastectomies, with reconstruction, were nipple-sparing. By 2011, it had grown to 28%, and the trend seemed to be continuing into 2012.”

In September 2011, with the approval of the Institutional Review Board, Dr. Coopey and her colleagues created an NSM database, retrospectively entering patients’ data for the years 2007 to 2011, and prospectively entering them from that point forward. The study assessed trends in patient selection and outcomes between the two time periods. Dr. Coopey presented the study at the American Society of Breast Surgeons’ annual meeting (Ann Surg Oncol 2013, Aug. 13. [Epub ahead of print]).

Altogether, the study included 645 consecutive NSMs in 370 patients with a mean age of 47 years and a mean BMI of 24 kg/m<00B2>. Few of the patients were active smokers or diabetic. The indication for NSM was risk reduction in 330 breasts, invasive cancer in 226, and ductal carcinoma in situ in 89.

The mean invasive tumor size was 1.8 cm, and the mean estimated tumor-to-nipple distance was 4 cm, with 25% of the patients having a tumor-to-nipple distance of less than 2 cm. Fifty-one patients had positive lymph nodes; 27 had undergone neoadjuvant chemotherapy; and 48 breasts had received previous radiation. Most of the patients underwent a single-stage implant reconstruction, with 96% having tissue expander or implant-based reconstruction.

The surgeons used a variety of incisions, favoring the inferolateral incision, which begins at the 6 o’clock position of the intramammary fold, travels along the fold and up along the lateral portion of the breast for 10 to 12 cm.

“We feel this gives the best cosmetic result and allows for greatest access to the axilla,” Dr. Coopey said.

Total nipple necrosis occurred in 1.7% of breasts, and an additional 3.7% of nipples needed to be removed due to positive subareolar/nipple margins. At a mean follow-up of 22.1 months, local recurrence occurred in four of the 156 breasts that had been operated on for cancer between the years 2007 and 2011, and four of those recurrences happened in patients with genetic mutations.

“To date, no recurrences have occurred in patients operated on in 2012, and no recurrence has involved a nipple–areolar complex [NAC],” Dr. Coopey said. “Also, no prophylactic NSM patient has developed breast cancer.”

Patients in the 2011-2012 group had a higher rate of positive lymph nodes, which is not surprising given that they were more likely to have a cancer diagnosis than those in the earlier group. The later group also had a significantly higher BMI (24.4 vs. 22.9 kg/m2) and significantly higher breast volume (519 vs. 366 cm3). “Despite this, there was no difference in total nipple necrosis rates between the two groups,” Dr. Coopey said.

The 2011-2012 group also included more current smokers, more patients with diabetes, and more patients who had undergone neoadjuvant chemotherapy, although the differences between those proportions were not significant.

In summary, Dr. Coopey’s team found that the eligibility for NSM at their institution had expanded to include women with higher BMI and larger breasts, with no increase in nipple loss due to ischemia.

“We also found the rate of positive subareolar/nipple margins decreased over time, even when more operations were being performed for cancer, suggesting improved patient selection,” Dr. Coopey said.

The researchers concluded that in the absence of absolute contraindications (i.e., clinical or imaging evidence of NAC involvement; locally advanced breast cancer with skin involvement; inflammatory breast cancer; and bloody nipple discharge), NSM should be considered for patients who at one time might not have been given that option, including patients with cancer, higher BMI and larger breasts.

Shawna Willey, MD, vice chair, Clinical Affairs, Department of Surgery and director, Betty Lou Ourisman Breast Health Center at MedStar Georgetown University Hospital, Washington, D.C., has witnessed a similar trend at her institution.

“I think there was appropriate caution early in the course of doing NSM, and as with many operations, the contraindications were broad so that we could be sure that it was a safe approach and that we weren’t compromising the oncologic care of patients,” Dr. Willey said.

“We are now seeing that the guidelines we published out of Georgetown in 2009 have become passé, and we know now that we can expand the indications safely as long as we pay attention to margins and characteristics of the skin,” she said.