Study: What is the risk of breast cancer recurrence after nipple-sparing mastectomy?

IN-DEPTH REVIEW OF RESEARCH

Study background:

Nipple-sparing mastectomies (NSMs) improve post mastectomy cosmetic outcomes for women who have breast cancer or have a high-risk for it. An increasing number of women undergoing mastectomy for breast cancer are candidates for NSM, including those with larger, node-positive cancers who receive neoadjuvant (before surgery) chemotherapy and/or post-mastectomy radiation therapy. As a result, more women are requesting NSM. However, many surgeons and patients are concerned about long-term local recurrence or a new primary breast cancer that could results from breast tissue left beneath the retained nipple.

Researchers of this study wanted to know:

What is the long-term risk of recurrence following NSM?

Population(s) looked at in the study:

Between 2007 and 2012 at Massachusetts General Hospital, 2,182 NSMs were performed in 1,258 patients who were treated for breast cancer or risk reduction. Patients were excluded only if they had cancerous cells in their nipple-areola complex, locally advanced breast cancer in the skin, inflammatory breast cancer, bloody nipple discharge, or if their overly large or droopy breasts would result in undesirable nipple placement on their reconstructed breasts.  Data on patients and tumor characteristics; local and systemic treatments; and local, regional and distant recurrence were obtained from patients’ medical records.  Outcomes were determined for 311 women with stage 0 to III breast cancer; within this cohort:

• 240 (77%) had invasive cancer and 71 (23%) had ductal carcinoma in situ (DCIS)
• Tumor stages among the 284 patients who did not receive neoadjuvant chemotherapy included:
  • 25.0% stage 0
  • 50.7% stage I
  • 17.6% stage II
  • 6.7% stage III
• 33 (11%) of 297 patients had germline mutations in high-risk genes (20 in BRCA1, 10 in BRCA2, 2 in p53, and 1 in PTEN).

Study findings: 

Median follow-up was 51 months (ranging from 4 to 101 months). During the follow-up period, 17 patients developed a recurrence. Estimated disease-free survival was 95.7% at 3 years and 92.3% at 5 years. No recurrence involved the retained nipple-areola complex. Among patients with recurrent disease there were:

• 11 (37%) locoregional recurrences
• 8 (2.7%) distant recurrences
• 2 patients with simultaneous locoregional and distant recurrences
• 3 of the 7 chest wall recurrences in mutation carriers were:
  • 1 patient with a p53 mutation and bilateral breast cancer
  • 2 patients with BRCA1 mutations, 1 of whom had triple-negative cancer and refused chemotherapy
• No recurrences were found in the retained nipple-areola complex in any of the 2,182 patients who had NSM performed during the study period

Limitations:

The authors recognize there may have been a selection bias and that NSM may have been offered disproportionately to patients who had a good prognosis. Although Massachusetts General no longer bases their recommendations for NSM on tumor size, receptor status or stage, these factors may have influenced recommendations during the study period. The researchers also concede that although their follow-up period is long enough to exclude early recurrences with aggressive breast cancer types, it may not be sufficient for determining risk of recurrence for hormone receptor-positive cancers, especially since the predicted risk of recurrence in this population of patients with predominately early-stage disease would be predicted to be low. They are planning a supplemental study with a longer follow-up period to better estimate the risk of recurrence after NSM in these patients.  

Conclusions:

Women with any of the following conditions are not candidates for NSM: any evidence of cancerous involvement of the nipple and/or areola; tumors close to the nipple-areola complex that could compromise margins; locally advanced breast cancer involving the skin, or inflammatory breast cancer; or large or sagging breasts that would result in an undesirable nipple placement on the reconstructed breast.  Furthermore, NSM is not without challenges, and there is no guarantee that everyone who has it will experience ideal or even satisfactory results. Loss of sensation in the nipples is expected after NSM because nerves are cut when tissue is removed. Patients with unrealistic expectations, who struggle emotionally or who expect full nipple sensation to return may not be good candidates for a NSM.

To date, no study has compared recurrence rates between NSM and standard mastectomy by randomly assigning women to one or the other procedure. However, the low local recurrence rate observed in this and other studies suggest that patients who undergo NSM do not have an increased risk of recurrence. Women planning a mastectomy should ask their surgeons whether they are eligible for a nipple-sparing operation, and what benefits and limitations they should expect.

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Posted 1/25/18

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