Critical study of resection margins in adult soft-tissue sarcoma surgery

Introduction: Resection margins constitute a recognized risk factor for local recurrence, but their impact on survival is less clear.

Hypothesis: Infiltrative proliferation and satellite nodules are prognostic factors for local and systemic aggressiveness.

Type of study: Retrospective cohort study.

Patients and methods: In 105 patients under curative treatment, resection quality was assessed on UICC criteria (R0/R1) and on a modified version (R0M/R1M) taking account of proliferation contours and satellite nodules for narrow margins (<1mm). Uni- and multi-variate analysis was performed, and Kaplan-Meier survival curves were compared on log-rank.

Results: Mean 5-year local recurrence-free survival (LRFS) was 0.64 [0.52-0.76] after R1 surgery, 0.9 [0.85-0.95] after R0, 0.64 [0.519-0.751] after R1M and 0.92 [0.87-0.96] after R0M. Resection type according to R classification correlated with disease-free survival (DFS) (P=0.028), but not with metastasis-free survival (MFS) (P=0.156). Resection type according to RM classification correlated with DFS and MFS. Multivariate analysis disclosed correlations between LRFS rate and RM resection type (HR 6.77 [1.78-25.7], P=0.005), DFS rate and RM resection type (HR 2.83 [1.47-5.43], P=0.001) and grade (HR=3.17 [1.38-7.27], P=0.003), and MFS and grade (HR=3.96 [1.50-10.5], P=0.006).

Discussion: The microscopic aspect of the proliferation contours and presence of satellite nodules were confirmed as prognostic factors for local and systemic aggressiveness. They impact both disease-free survival and metastasis-free survival in case of margins less than 1mm. Their systematic consideration may help identify patients with elevated systemic risk.

Level of evidence: IV.