STRASS (EORTC 62092)

STRASS, EORTC 62092, randomised 266 patients with primary resectable retroperitoneal sarcoma across European and North American sarcoma centres to preoperative radiotherapy followed by surgery or surgery alone. Its primary endpoint of abdominal recurrence-free survival was not improved by radiotherapy, and preoperative treatment added toxicity and delayed surgery. An unplanned subgroup analysis suggested a benefit in well-differentiated and low-grade dedifferentiated liposarcoma, which continues to be studied but did not change the primary result. Published in Lancet Oncology in 2020, it made surgery alone the standard for most retroperitoneal sarcomas and shifted attention to neoadjuvant chemotherapy (STRASS2).