Patients with breast cancer who undergo nipple-sparing mastectomy (NSM) have a low rate of disease recurrence within the first 5 years after surgery, according to new findings published online in the Journal of the American College of Surgeons. The findings come from a review at a single institution. Among 311 patients who had NSM, the recurrence rate at a median follow-up of 51 months was 5.5%, and no recurrences involved the retained nipple areola complex.
The estimated disease-free survival rates were 95.7% at 3 years and 92.3% at 5 years.
The recurrence rate in this study is similar to reported rates of disease recurrence after standard mastectomy, explained lead author, Barbara L. Smith, MD, PhD, a surgical oncologist and director of the Breast Program at Massachusetts General Hospital in Boston.
No randomized controlled trials have compared NSM to skin-sparing mastectomy or mastectomy without reconstruction, but retrospective cohort studies have shown no significant difference in local or distant recurrence rates between the two procedures, she commented.
NSM provides patients with superior cosmetic results, and the results of this study further support that NSM does not negatively affect oncologic outcomes, she said.
"Our study, which has one of the longest reported follow-ups after therapeutic NSM in the United States, provides additional support that it's safe to leave the nipple intact during mastectomy, with only a few exceptions," said Dr Smith.
In an interview, Dr Smith explained that the skin is a separate organ from the breast, and the nipple is really part of the skin. "Over the years, we have been saving more skin, and with better cosmetic results," she said.
The technique used at their institution, she pointed out, leaves only the nipple and areola and little to no breast or ductal tissue beneath the nipple-areola complex.
"Cosmetically it looks so much better than what we can do with nipple reconstruction," Dr Smith said. "It can also improve reconstruction options. If you leave the nipple and the skin envelope is intact, you can have a much more simplified technique — many women will be able to avoid skin expanders."
The procedure is becoming more acceptable, especially with growing evidence that it is safe, and will become increasingly more common as women push for it, she predicts.
"It is similar to when women began to ask for lumpectomies when mastectomy was the standard," Dr Smith said. "In our practice, anyone is eligible if they don't have tumor growing into the nipple, although right now, women with very large breasts are not good candidates as it will result in an unacceptable location of the nipple."
In this study, Dr Smith and her colleagues reviewed the oncologic outcomes of consecutive therapeutic NSM at a single institution.
A total of 2182 NSMs were performed in 1258 patients with breast cancer or for risk reduction between June 2007 and December 2016, and oncologic outcomes were assessed for the 311 of these procedures that were performed in 297 patients for stage 0 to III breast cancer.
Within this cohort, 240 (77%) NSMs were for invasive cancer and 71 (23%) were for ductal carcinoma in situ, and among the 284 patients who did not receive neoadjuvant chemotherapy, 25.0% had stage 0 disease, 50.7% had stage I, 17.6% had stage II, and 6.7% had stage III.
At 51 months' median follow-up, cancer recurred in 17 patients. Within this group, there were 11 (3.7%) locoregional recurrences and 8 (2.7%) distant recurrences; 2 patients experienced simultaneous locoregional and distant recurrences.
No recurrences involved the retained nipple areola complex in any patient. Seven patients did experience a chest wall recurrence: 3 mutation carriers, 1 patient with a p53 mutation and bilateral breast cancer, and 2 patients with BRCA1 mutations.
In addition, 2 breast cancer–related deaths occurred in patients who developed isolated distant recurrences.
No new breast cancers occurred in 170 prophylactic NSMs that were performed in BRCA mutation carriers during this same time period.
Commenting on the study, Sarah P. Cate, MD, an assistant professor of surgery at the Icahn School of Medicine at Mount Sinai Medical Center in New York, and director, Special Surveillance and Breast Program, noted that the weaknesses of the study are that it was retrospective, and "there may be some selection bias of patients being offered nipple-sparing mastectomies, which the authors acknowledge."
"NSM is being offered to the majority of our breast cancer patients who do not have direct involvement of the nipple areolar complex," Dr Cate told Medscape Medical News.
J Am Coll Surg. Published online July 17, 2017. Abstract
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Cite this: Nipple-Sparing Mastectomy as Safe as Standard Procedures - Medscape - Jul 24, 2017.