Top Line: Should patients with retroperitoneal sarcoma receive pre-operative radiation?
The Study: The rationale for radiation is extrapolated from extremity sarcoma, and a recent NCDB analysis even suggests that both pre- and post-operative radiation are associated with improved overall survival. In the STRASS trial, 266 patients with retroperitoneal sarcoma (RPS) were randomized to surgery with or without neoadjuvant RT (50.4 Gy in 28 fractions). The study used a complex primary outcome of abdominal recurrence free survival (ARFS) that was designed to account for both local recurrences and events that jeopardized curative resection. Overall, there was no difference in the rate of ARFS at 3 years (59 vs 60%) or median ARFS (4.5 years vs 5 years). However, there are several important points to consider. First, there were twice as many local recurrences (39 vs 17) with surgery alone. Second, 14% of patients in the RT arm had an “event” during radiation (most were local progression with subsequent R0 resection). Finally, liposarcoma represented close to 75% of the overall cohort and is more likely to recur locally. Unplanned exploratory analyses accounting for these factors did show a “trend” towards better ARFS with RT (especially for liposarcoma). Applied broadly, neoadjuvant RT doesn't improve survival outcomes for RPS. There may be carefully selected groups of patients, though, for whom there is a meaningful local control benefit.TBL: Despite a lower rate of local recurrences, preoperative radiation with 50.4 Gy in 28 fractions for retroperitoneal sarcomas did not improve abdominal recurrence-free survival or overall survival. | Bonvalot, Lancet Oncol 2020