Adjuvant Radiotherapy for extremity and trunk wall Atypical Lipomatous Tumor/Well-Differentiated LPS (ALT/WD-LPS): A French Sarcoma Group (GSF-GETO) study
Menée à partir de données portant sur 283 patients traités entre 1984 et 2011 pour un liposarcome bien différencié ou une tumeur lipomateuse du tronc ou des extrémités (âge : de 25 à 94 ans ; durée médiane de suivi : 61,7 mois), cette étude française multicentrique évalue, du point de vue du taux de survie sans récidive locale à 5 ans, de la survie sans progression et de la survie globale, l'intérêt d'une radiothérapie adjuvante
Résumé en anglais
Background : The role of adjuvant radiotherapy (RT) in the management of ALT/WD-LPS remains controversial.
Methods : 283 patients (pts) 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 pts. Median age at diagnosis was 61 (range 25-94), 147 pts (52%) were males, 222 (78%) pts 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 pts (47%). Pts 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 pts developed metastasis during follow-up. The 5-year local relapse-free survival rates were 98.3% vs 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 vs 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.
