Key clinical point: After R0 or R1 resection of limb or superficial trunk myxofibrosarcoma, the 5-year local relapse–free survival was 67%. Three prognostic factors influenced local control: patient age, R0 resection, and adjuvant radiotherapy.

Major finding: The 5-year overall survival was 80%. The 5-year metastasis-free survival was 83%. The 5-year local relapse–free survival was 67%; independent prognostic factors for local relapse were R1 resection (hazard ratio [HR] = 1.26; P = .001) and adjuvant radiation therapy (HR = 0.35; P = .0001). In stratified analysis, adjuvant radiation therapy was beneficial after R0 resection (P = .0020) and after R1 resection (P = .0001).Independent prognostic factors for metastatic relapse were grade 3 disease (HR = 1.975; P = .0001) and tumor size (HR = 1.006; P = .001).

Study details: This was a retrospective multicenter study of 425 patients who had nonmetastatic disease and underwent surgery as part of the French National Group and were enrolled in the Conticabase. Median age was 66 years; 53% were males; 85% of cases occurred in limbs or superficial trunk; median size was 60 mm; 47% and 39% were grades 2 and 3, respectively; 66% had R0 resection and 34% R1 resection. Adjuvant radiation therapy was given to 65% of patients, neoadjuvant radiation therapy to 3%, neoadjuvant chemotherapy to 7%, and adjuvant chemotherapy to 13%. The median follow-up was 51 months.

Disclosures: The authors had no relevant disclosures.

Source: Boughzala-Bennadji R et al. Intl J Rad Oncology*Biology*Physics; October (102) 2018: 399-406. https://doi.org/10.1016/j.ijrobp.2018.05.055