Tumor-to-Nipple Distance as a Predictor of Nipple Involvement: Expanding the Inclusion Criteria for Nipple-Sparing Mastectomy.

BACKGROUND: A tumor-to-nipple distance of greater than 2 cm has traditionally been considered a criterion for nipple-sparing mastectomy. This study evaluates whether magnetic resonance imaging and sonographic measurements of tumor-to-nipple distance accurately reflect the risk of nipple involvement by disease. METHODS: All nipple-sparing mastectomy cases with implant-based reconstruction performed by the senior author between July 2006 and December 2014 were retrospectively reviewed. Therapeutic cases with preoperative magnetic resonance imaging or sonography were included. RESULTS: One hundred ninety-five cases were included. Preoperative imaging consisted of sonography (n = 169), magnetic resonance imaging (n = 152), or both (n = 126). With sonography, nipple involvement did not differ between nipple-sparing mastectomy candidates and noncandidates using a tumor-to-nipple distance cutoff of 2 cm (10.7 percent versus 10.6 percent; p = 0.988) or 1 cm (9.3 percent versus 15.0 percent; p = 0.307). With magnetic resonance imaging, nipple involvement did not differ between candidates and noncandidates using a cutoff of 2 cm (11.6 percent versus 12.5 percent; p = 0.881) or 1 cm (11.4 percent versus 13.8 percent; p = 0.718). When sonography and magnetic resonance imaging findings were both available and concordant, nipple involvement still did not differ between candidates and noncandidates using a cutoff of 2 cm (8.8 percent versus 11.8 percent; p = 0.711) or 1 cm (7.6 percent versus 14.3 percent; p = 0.535). CONCLUSION: A tumor-to-nipple distance as small as 1 cm, as measured by sonography or magnetic resonance imaging, should not be considered a contraindication to nipple-sparing mastectomy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.