49P The impact of unplanned excision ‘whoops surgery’ with or without surgery in outcome of trunk and extremity soft tissue sarcoma patients: A retrospective analysis

Abstract

Extremity soft tissue sarcomas are rare neoplasms. Because these tumors are usually pseudo-capsulated, many practices are initially thought to be benign and are excised without a proper preoperative imaging, biopsy, or planning by an unwary surgeon. These excisions have termed “Whoops! Procedure” indicating the surprise and distress that the surgeon experiences, after the pathologist reports a malignant neoplasm in a postoperative specimen. We aimed at studying the oncological outcomes of patients undergoing unplanned (whoops) excision for soft-tissue sarcomas (STS) at a tertiary cancer institute. This was a retrospective analysis of patients of STS of trunk and extremity from 2017 to 2021. we compared patients who had undergone ‘whoops’ surgery with or without re-surgery versus patients had undergone wide local excision WLE for the oncological outcomes, including overall survival (OS) and disease-free survival (DFS). After excluding patients with gross residual (R2) and incomplete medical data, Sixty-nine patients were included with median age of 44, patients were divided into two groups: group 1 included 44(63.7%) who underwent whoops surgery and group 2 included 25 (36.3%) underwent WLE. The median follow-up period was 39.6 months. Group 1 were more likely to have smaller tumors (T1-2) 31 patients (70.4%) vs 9 patients (36%) in group 2. Considering margin; R0 was achieved in 4 patients (9.5%) and R1 in 38 patients (90.5%) in group 1 vs R0 in 17 patients (68%) and R1 in 8 patients (32%) in group 2. There were 9 (20.5%) local recurrences in group 1 and 3 (12%) in group 2 (P=0.411). There was no difference in DFS and OS in both groups. The median DFS in group 1 was 21.3 months vs 32.3 months in group 2 (p=0.414), the median OS was 42 months in group 1 vs 38.5 months in group 2 (p=0.974). There was no significant difference in local recurrence in the whoops group between patients who underwent re-excision or not. Also there was no difference in median DFS in re-resection group which was 7.7 months vs 27.5 months in patients who had not undergone re-resection (p=0.06). Although local recurrence is much more common in the whoops surgery group, re-resection does not seem to affect DFS or OS.