Occult Nipple Involvement in Breast Cancer

[Hopeful]

This study is of interest to me, as I have many of the predisposing factors they discuss: Her2+, mixed DCIS and IDC, and a retroareolar tumor that was close to the nipple.

Eur J Cancer. 2009 Aug 31; Epub ahead of print, EF Brachtel, JE Rusby, JS Michaelson, LL Chen, A Muzikansky, BL Smith, FC Koerner

Supplementary editorial provided by OncologySTAT

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Analysis of 316 mastectomy specimens provided data used to determine risk factors for nipple involvement in breast cancer. Factors predictive of nipple involvement included HER2 amplification, tumor size, and tumor-nipple distance. Nipple-sparing mastectomy may be suitable for patients at low risk for nipple involvement.
STUDY IN CONTEXT

Sparing of the nipple in mastectomy results in superior cosmetic outcomes. However, the risk of inapparent nipple involvement is not well defined in cases where there is no gross involvement of the nipple. Previous studies reported a wide range in the incidence of occult nipple involvement, from 5.6% to 58%. This wide degree of variation may be attributed to methodologic weaknesses of the studies and changing trends in the indications for mastectomy over time. This study used mastectomy tissue to evaluate risk factors for occult nipple involvement in breast cancer. To provide guidance for choosing patients who may safely undergo nipple-sparing surgery, Brachtel et al evaluated the frequency, histopathology, and prognostic features of tumors that involve the nipple.
The nipples, areola, and retroareolar tissue in mastectomy tissue from 316 patients were sectioned using coronal sections, which permitted evaluation of all of the ducts leading to the nipple. Coronal sections were considered more useful than sagittal sections, with which involved ducts could potentially be missed. Mastectomy tissue was examined from 232 patients who underwent therapeutic mastectomy and 84 patients who underwent prophylactic mastectomy. Breasts were excluded if they had grossly apparent nipple involvement.
The nipple was involved in 21% of breasts removed for therapeutic mastectomy (n = 49), whereas none of the prophylactic mastectomy samples had nipple involvement. Among breasts with tumors that involved the nipple, the majority (62%) were of ductal carcinoma in situ (DCIS) histology. On univariate analysis, factors associated with increased risk of occult nipple involvement included larger tumor size, amplification of human epidermal growth factor receptor 2 (HER2), lower tumor-nipple distance, the presence of invasive carcinoma and DCIS, higher histologic grade, DCIS 3, the presence of lymphatic invasion, and N2/N3 lymph node status. On multivariate analysis, tumor size, tumor-nipple distance, and HER2 amplification were independent predictors of nipple involvement. In addition, carcinoma in the retroareolar region was associated with nipple involvement.
The incidence of nipple involvement in this study falls within the middle range reported by previous studies. Changes in diagnostic methods and the propensity to use lumpectomy, as well as methodologic differences between the studies, may be responsible for the different incidence rates reported in the studies. Retroareolar sampling may be used to test for occult nipple involvement.



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