Abstract P1-20-12: Robotic versus conventional or endoscopic-assisted nipple sparing mastectomy with immediate prosthesis breast reconstruction in the management of breast cancer- A case control comparison study with analysis of clinical outcomes, patient-reported aesthetic results, and medical cost
Authors: Lai Hung-Wen , Chen Shou-Tung , Chen Dar-Ren 
Published: March 2020

Abstract
Background: Nipple-sparing mastectomy (NSM), which preserved the nipple areolar complex (NAC) and skin flap during mastectomy, was increasingly performed in breast cancer patients due to better cosmetic outcome, higher patient satisfaction, and maintained oncologic safety. Minimal invasive surgery had become the main stream of operations, and new surgical innovations of NSM, like endoscopic nipple sparing mastectomy (E-NSM) or robotic nipple sparing mastectomy (R-NSM), were emerging and applied in the surgical treatment of breast cancer. However, evidence comparing R-NSM to conventional NSM (C-NSM) or E-NSM was lacking. A case control comparison study was conducted for patients with breast cancer underwent C-NSM, E-NSM, or R-NSM with IPBR at a single institution to compare the clinical outcomes, patient-reported cosmetic results and medical cost.
Methods: To compare the efficacy and benefit between R-NSM, C-NSM and E-NSM, a case control comparison study was conducted. Patients with primary operable breast cancer who underwent NSM from January 2011 to May 2019 were retrieved from a prospectively maintained breast cancer database at Changhua Christian Hospital (CCH), a tertiary medical center in Taiwan. To reduce sampling bias from surgical technique or related factors, only patients operated by HWL were enrolled for this comparison analysis. In addition, in order to reduce the possible variations in cosmetic outcomes derived from different types of breast reconstruction, only patients who received immediate cohesive gel implant breast reconstructions were retrieved. Patients who had received previous breast conserving surgery or previous radiation to chest wall were excluded.
Results: Altogether, there were a total of 57 patients in the R-NSM with IPBR group, 65 C-NSM and IPBR, and 100 patients in E-NSM with IPBR group in this case control comparison study. The three groups were comparable in terms of age, location of tumor, pathologic tumor size, grade, resected mastectomy weight, and stage of disease. Compared with C-NSM, R-NSM was associated with less blood loss (mean 35 ± 32 versus 104 ± 71 ml, P&lt;0.01) and higher overall satisfaction (96.4% excellent and 3.6% good versus 75.6% excellent and 24.4% good, P=0.02) in patients’ reported cosmetic results. There is a trend (though statistically not significant) of lesser complication rate, and NAC ischemia/necrosis rate of R-NSM if compared with C-NSM. However, longer operation time (mean 247 ± 61 versus 197 ± 80 minutes, P&lt;0.01), and higher over medical cost (10,877 ± 796 versus 5,702 ± 661 US Dollars, P&lt;0.01) was observed in R-NSM group. The surgical margin involvement rate in both R-NSM (1.8%) and E-NSM (4%) procedures were relatively low (P=0.52). R-NSM group was associated with higher satisfaction rates in terms of scar appearance, scar length, and surgical wound position if compared with E-NSM group. Compared with E-NSM, R-NSM took longer operation time (241 ± 61 versus 215 ± 70 mins, P=0.01), less blood loss (32 ± 29 versus 79 ± 62 ml, P&lt;0.01), and higher medical cost (10,587 ± 554 versus 6,855 ± 936 US Dollars, P&lt;0.01). There was no statistically significant difference in nipple ischemia/necrosis or overall complication between R-NSM and E-NSM.
Conclusion: R-NSM compared favorably to C-NSM with comparable clinical outcomes, minimal blood loss and higher patients’ satisfaction but at the expense of higher cost and longer operation time. R-NSM was associated with higher would related satisfaction and lesser blood loss if compared with E-NSM, however, at the price of longer operation time and higher medical cost.
Citation Format: Hung-Wen Lai, Shou-Tung Chen, Dar-Ren Chen. Robotic versus conventional or endoscopic-assisted nipple sparing mastectomy with immediate prosthesis breast reconstruction in the management of breast cancer- A case control comparison study with analysis of clinical outcomes, patient-reported aesthetic results, and medical cost [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-20-12.