Adjuvant radiotherapy for extremity and trunk wall atypical lipomatous tumor/well-differentiated LPS (ALT/WD-LPS): a French Sarcoma Group (GSF-GETO) study.

In this retrospective study we should that adjuvant radiotherapy efficiently prevents recurrence of atypical lipomatous tumors (also called well differenciated liposarcomas of the extremities and trunk wall). However because these tumors are considered benign, the risk of morbidity due to tumor recurrence should be carefully weighted against that of radiation induced tumors.Background The role of adjuvant radiotherapy (RT) in the management of atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WD-LPS) remains controversial. Methods Two hundred eighty-three patients with operable ALT/WD-LPS, no history of previous cancer, chemotherapy (CT) or RT, treated between 1984 and 2011 registered in the Conticabase database were included and described. Overall (OS), progression-free survival (PFS) and time to local relapse (TTLR) were evaluated from the time of first treatment. Results Three of 20 centers enrolled 58% of the patients. Median age at diagnosis was 61 (range 25–94) years, 147 patients (52%) were males, 222 (78%) patients had their primary tumor located in an extremity while 36 (13%) and 25 (9%) had tumors involving the girdle and the trunk wall, respectively. The median size of primary tumors was 17 cm (range 2–48 cm). Adjuvant RT was given to 132 patients (47%). Patients who received adjuvant RT had larger tumors (P = 0.005), involving more often the distal limbs (P < 0.001). Use of adjuvant RT varied across centers and along the study period. Other characteristics were balanced between the two groups. Median follow-up was 61.7 months. None of the patients developed metastasis during follow-up. The 5-year local relapse-free survival rates were 98.3% versus 80.3% with and without adjuvant RT, respectively (P < 0.001). Once stratified on time period (before/after 2003), adjuvant RT, tumor site and margin status (R0 versus other) were independently associated with TTLR. No OS difference was observed (P = 0.105). Conclusion In this study, adjuvant RT following resection of ALT/WD-LPS was associated with a reduction of LR risk. [ABSTRACT FROM AUTHOR]