Abstract P2-14-16: Comparison of robotic nipple sparing mastectomy (R-NSM) to endoscopic assisted nipple sparing mastectomy (E-NSM) in the management of breast cancer
Authors: Lai H-W , Chen S-T , Chen D-R , Kuo S-J 
Published: May 2019

Background: Endoscopic assisted nipple sparing mastectomy (E-NSM) alone or followed by immediate breast reconstruction (IBR) with implants or autologous flaps were reported to be associated with small inconspicuous incision and good cosmetic outcome. Robotic nipple sparing mastectomy (R-NSM), which introduce da Vinci surgical platform through a small axillary wound to perform NSM with (or without) IBR, was reported to have potential to overcome the technique difficulty of E-NSM and showed promising cosmetic outcome. However, few evidence was available compared the effectiveness and safety of R-NSM compared with E-NSM in the management of breast cancer.

Methods: Patients with breast cancer received E-NSM or R-NSM performed from July 2010 to June 2018 were searched from breast surgery database at Changhua Christian Hospital (CCH), Taiwan. Data on clinicopathologic characteristics, type of surgery, complications and recurrence were analyzed to determine the effectiveness and oncologic safety of R-NSM and E-NSM. Patient-reported cosmetic outcome result was also obtained and compared.

Results: A total of 127 E-NSM and 36 R-NSM procedures were found and data collected for analysis. About 77.8% of R-NSM group received breast reconstruction, and 78% of E-NSM group received breast reconstruction (P=0.982). The surgical margin involved rate was 2.8%(1/36) in R-NSM versus 3.4%(5/127) in E-NSM (P=1). The overall operation time was 281.5 ± 77.0 mins in R-NSM group versus 210.8 ± 55.5 mins in E-NSM group (P &lt;0.001). Blood loss was mean 36.5 ± 33.7 ml in R-NSM group versus 88.0 ± 61.0 ml in E-NSM group (P &lt;0.001). The hospital stay was 6.8 ± 1.3 days in R-NSM group versus 5.1 ± 1.3 in E-NSM group (&lt;0.001).

-From learning curve analysis, about 15-17 cases needed to significantly decrease operation time in E-NSM group, and in R-NSM group around 10-12 cases needed.

-About 50 E-NSM and 25 R-NSM patients received post-operative questionnaire survey for cosmetic outcome evaluation and acceptance of operations. Patient-reported outcome survey showed that the satisfaction rate of R-NSM 96.4% group versus 94.8 in E-NSM group (p=0.96). The will to receive the same operation again if they could chose again: 100% in E-NSM group versus 96.4% in R-NSM group.

-Cost analysis- The breast cancer operation cost was reimbursed by national insurance in Taiwan. The additional cost of E-NSM and IBR with Gel implant was 4,000-6,000 USD (according to different type of implants used). The cost of R-NSM and IBR with Gel implant was 10,000-12,000 USD (according to different type of implants used). The cost difference was about 2,500-3,300 USD higher in R-NSM group than in E-NSM group.

Conclusion: Both E-NSM and R-NSM were equally effectively in the management of breast cancer with no different surgical margin involved rate, however, longer follow-up remained mandatory for oncologic safety evaluation. Shorter learning curve indicated more friendly operation plateform of robotic surgery in performing NSM. Relative longer operation time, and higher cost of R-NSM compared with E-NSM was observed. Longer hospitalization is biased from personal insurance consideration due to higher cost of R-NSM.

Citation Format: Lai H-W, Chen S-T, Chen D-R, Kuo S-J. Comparison of robotic nipple sparing mastectomy (R-NSM) to endoscopic assisted nipple sparing mastectomy (E-NSM) in the management of breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-16.