Abstract P2-12-09: Long-term follow-up of nipple-sparing mastectomy for early-stage breast cancer without radiotherapy: A single-center study at a Japanese institution

Introduction: Achievement of a good cosmetic outcome is one of the most important goals of surgical treatment of breast cancer. However, most patients must undergo a mastectomy if the outcome of breast-conserving surgery is discordant. All potential techniques that maintain oncological safety should be considered to maximize the cosmetic outcome for patients who require a mastectomy. We began performing nipple-sparing mastectomy (NSM) in 1978. Recent reports have suggested that NSM is oncologically as safe as mastectomy and affords a better cosmetic outcome. Conversely, the surgical complications and recurrence associated with NSM remain controversial. Objective: In the present study, we review the safety of the NSM surgical technique, discuss nipple–areola recurrence and skin flap recurrence after NSM, and compare recurrence and prognosis between NSM and mastectomy based on our long-term follow-up data. Patients and Methods: We retrospectively analyzed 723 patients with early-stage breast cancer who underwent NSM from 1985 to 2007. The patients' median age, tumor size, and tumor–areola distance were 50 y, 2.1 cm, and 1.5 cm, respectively. We used a thick skin flap method to avoid surgical complications including nipple and skin flap necrosis. We analyzed nipple–areola recurrence and skin flap recurrence after NSM. We also analyzed 100 patients who underwent mastectomy for early-stage breast cancer during the same period as those who underwent NSM. We compared the local recurrence rate (LRR), disease-free survival (DFS) rate, and overall survival (OS) rate among all 723 patients who underwent NSM and 100 patients who underwent mastectomy. No patients in either group received radiotherapy. Results: Among all patients who underwent NSM, stage 0, 1, 2A, and 2B disease was present in 21, 320, 253, and 129 patients, respectively. Notably, no nipple necrosis occurred during the average 114-month follow-up period. Local recurrence developed in 49 patients (6.7%), including recurrence at the nipple–areola complex in 24 (3.3%) and recurrence at the skin flap in 25 (3.4%). The average disease-free interval in patients with nipple–areola recurrence was 50 months, and that in patients with skin flap recurrence was 68 months. The clinical features of nipple–areola recurrence were a low rate of ER positivity (27%), high rate of Her2/neu positivity (60%), Paget type recurrence rate of 52%, and small tumor–areola distance (0.5 cm). The clinical features of skin flap recurrence were a relatively high rate of ER positivity (55%), solitary type recurrence rate of 88%, and diffuse type recurrence rate of 12%. The prognosis of diffuse type skin flap recurrence was significantly worse than that of solitary type recurrence (p = 0.01). There were no significant differences between the NSM and mastectomy groups in the LLR (6.7% vs. 4.0%, respectively), 10-y DFS rate (88% vs. 90%, respectively), or 10-y OS rate (92% vs. 91%, respectively). Conclusion: Our long-term follow-up data show that NSM should be considered as an alternative option for mastectomy when the outcome of breast-conserving surgery is discordant in patients with early-stage breast cancer. Citation Format: Sakurai T, Suzuma T, Yoshimura G, Jinta E, Umemura T, Sakurai T. Long-term follow-up of nipple-sparing mastectomy for early-stage breast cancer without radiotherapy: A single-center study at a Japanese institution. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-12-09.