Surgical and Oncologic Outcomes After Robotic Nipple Sparing Mastectomy and Immediate Reconstruction

Overview

Robotic mastectomy with immediate reconstruction was introduced by Toesca et al. in 2015. Since then, several studies have reported the safety and feasibility of robotic nipple-sparing mastectomy with immediate reconstruction. However, most studies were conducted by single centers and had small samples. Furthermore, there is a lack of studies comparing surgical and oncologic outcomes between robotic nipple-sparing mastectomy and conventional nipple-sparing mastectomy. For this reason, this study evaluates surgical and oncologic outcomes of robotic nipple-sparing mastectomy with immediate reconstruction using international multi-center data.

This study is an international multi-center pooled analysis using prospective and retrospective studies to evaluate surgical and oncologic outcomes of robotic nipple-sparing mastectomy with immediate reconstruction. Raw data for robotic or conventional nipple-sparing mastectomy from Severance Hospital, Samsung Medical Center, the European Institute of Oncology, Changhua Christian Hospital, and Gustave Roussy is collected. Among them, Severance Hospital takes the lead at performing analysis from the data. Storage and disposal of patients' records are managed by each researcher. In the analysis process, although the collaborators can request records from Severance Hospital if necessary, they are only supposed to be provided computerized data which were originally clinical data from patients who already ended treatments. In this case, individual identifying data and medical records are not shown. Clinicopathologic variables including operation times, hospital stay, medical history, smoking history, family history, BMI, menopausal status, specimen weight, TNM stage, grade, histological type, estrogen receptor, progesterone receptor, HER2, Ki 67, and perivascular involvement are analyzed. Postoperative complications within 30 days are collected and classified by the Clavien-Dindo grade. Locoregional recurrence-free survival and local and systemic recurrences are examined. Patients whose data have been retrospective for at least one month are to be examined. Patient's and surgeon's satisfaction using Breast Q is evaluated. Categorical variables are examined using the chi-square test or Fisher's exact test if indicated. Continuous variables are examined using the independent t-test or ANOVA if indicated. The estimated sample size from the four institutions is about 300 cases for robotic nipple-sparing mastectomy and matched cases for conventional nipple-sparing mastectomy. Propensity matching analysis is applied to reduce confounding factors.