# STRASS (EORTC 62092): preoperative radiotherapy plus surgery versus surgery alone for primary retroperitoneal sarcoma

Source: https://onco.cc/key-papers/paper-strass-lancet-oncol-2020/  
OnCo record `paper-strass-lancet-oncol-2020` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Adding radiotherapy before surgery for retroperitoneal sarcoma did not improve abdominal recurrence-free survival overall, so it is no longer routine, though a possible benefit in liposarcoma keeps it under discussion.

## Summary

Phase 3 trial of 266 patients with primary resectable retroperitoneal sarcoma randomised to preoperative radiotherapy (50.4 Gy) followed by surgery or surgery alone.

Median abdominal recurrence-free survival was 4.5 versus 5.0 years (hazard ratio 1.01), with more serious adverse events in the radiotherapy group; exploratory analysis suggested benefit in well-differentiated and low-grade dedifferentiated liposarcoma but not leiomyosarcoma.

## Fields

- Kind: Key paper
- Last checked: 2026-09-17
- Journal: The Lancet Oncology
- Year: 2020
- DOI: 10.1016/S1470-2045(20)30446-0
- Authors: Bonvalot S, Gronchi A, Le Péchoux C, et al.
- Findings: Median abdominal recurrence-free survival 4.5 vs 5.0 years; hazard ratio 1.01.; Serious adverse events 24 percent vs 10 percent.
- What it means: Surgery alone in a reference centre is the standard for primary retroperitoneal sarcoma; preoperative radiotherapy is considered case by case in liposarcoma.
- Caveats: Trial did not meet its endpoint, but the liposarcoma subgroup signal remains debated.; Surgery-alone arm had excellent outcomes at expert centres.

## Sources

- Lancet Oncol 2020: https://doi.org/10.1016/S1470-2045(20)30446-0
- PubMed: https://pubmed.ncbi.nlm.nih.gov/32941794/

## Connected records

- cancers: [Liposarcoma](https://onco.cc/cancers/liposarcoma/), [Retroperitoneal sarcoma](https://onco.cc/cancers/retroperitoneal-sarcoma/)
- trials: [STRASS (EORTC 62092)](https://onco.cc/trials/strass/)
- journals: [The Lancet Oncology](https://onco.cc/journals/lancet-oncology/)

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