Abstract PO4-22-11: Study to Compare the Safety of Immediate One-stage IBBR With Expander-Implant Two-stage IBBR Augmented With TiLoop® Bra(COSTA)

Abstract Background: The use of TiLOOP@ Bra in implant-based breast reconstruction (IBBR) becomes standard of care in mainland China. But evidence is limited about complication of one-stage and two-stage IBBR using TiLOOP@ Bra. A prospective randomized trial was conducted to compare the safety of immediate IBBR with that of immediate-delayed IBBR, both with TiLOOP@ Bra. Methods: We did an open label, randomized, controlled trial in eleven hospitals in the mainland China. Inclusion criteria: Women aged above 18 with cT0-T2N0M0 breast carcinoma which requires to undergo nipple or skin-sparing mastectomy (NSM or SSM) and immediate IBBR. Randomization was done electronically, stratified per center and in blocks of four of six to achieve approximately balanced groups of patients assigned to undergo one-stage or two-stage IBBR. Both procedures were undergone pectoralis major and TiLOOP@ Bra to build pockets. The primary endpoint of the present study was the incidence of postoperative complications (within 90 days after surgery), while the secondary endpoints were the quality of life at 18 months after surgery, satisfaction with breast appearance, aesthetic scores of reconstructed breasts, type of reoperation and TiLOOP@ Bra angiopathological assessment. This study is registered at clinicaltrials.gov, number NCT03589924. Findings: Between June 2018 and May 2022, a total of 418 eligible patients were randomly assigned to either two-stage implant reconstruction (n=194) group or immediate one-stage implant reconstruction (n=224) group. In terms of surgical procedures, NSM was more commonly (72.7%) chosen, with the two-stage implant reconstruction group having a lower proportion compared to the immediate one-stage implant reconstruction (66.3% vs. 78.3%; p=0.010). At 3 months after breast reconstruction surgery, the incidence of complications was lower in the two-stage implant reconstruction group than that in the immediate one-stage implant reconstruction group, with significant difference of 14.5% vs 23%; p=0.038. The incidence of nipple or areola necrosis was lower in the two-stage implant reconstruction group compared to the immediate one-stage implant reconstruction group, with statistically significant difference of 9.8% vs 17.1%; p=0.048. The implant loss rate was only 0.7%. It was discovered that the incidence of severe complications was lower in the two-stage implant reconstruction group than in the immediate one-stage implant reconstruction group (2.6% vs. 3.7%), and the difference was not statistically significant. Patients who experienced complications had a higher proportion of chemotherapy (69.2% vs. 38.9%; p 0.001), endocrine therapy (74.4% vs. 53.9%; p=0.002), and targeted therapy (24.4% vs. 9.6%; p=0.001), and the differences were statistically significant. In terms of surgical procedures, 67 (85.9%) patients who experienced complications underwent NSM, while the proportion of NSM in patients who did not experience complications was lower at 69.6%, which were 231 patients, and the difference was statistically significant (p=0.011). In addition, the complication incidence of patients who received implants sizes of 300-400ml was higher than that of the group that did not (32.1% vs. 17.8%; p=0.012). Conclusion: Both one-stage and two-stage TiLOOP@-assisted IBBR demonstrated perioperative safety. The complication rate within three month of two-stage is lower than one-stage. The implant loss rate was only 0.7% perioperatively. Our results suggest that use of TiLOOP@ Bra be considered carefully for one-stage NSM with IBBR but can be considered for SSM patients. Citation Format: Benlong Yang, Jian Liu, Haibo Wang, Yiding Chen, Cuizhi Geng, Nanyan Rao, Siyuan Han, Antai Zhang, Jinping Shi, Qiang Zhang, Wenhe Zhao, Jiong Wu. Study to Compare the Safety of Immediate One-stage IBBR With Expander-Implant Two-stage IBBR Augmented With TiLoop® Bra(COSTA) abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-22-11.