143P Prognostic factors associated with long-term survival in advanced LMS

Results: Among 402 patients (n=210; 52% female), baseline characteristics and histologic subtype distributions were similar between sex; including age (60 vs. 60 yrs, p=0.4), side (left 49% vs. 47%, p=0.7), or tumor size (18 cm vs. 20 cm, p=0.11).Female patients had more frequently tumor located in the pelvis (14% vs. 6.8%,p=0.021).Final pathology differed (p=0.010) with more LMS in females (22% vs. 9.4%) and less DDLPS (34% vs. 44%), but grade (p=0.14) and rate of R0 resection (p=0.6) were similar.There were no differences in neoadjuvant treatment but female had more frequently postoperative radiotherapy (18% vs. 11%, p = 0.043).Female patients had better overall survival (OS; 81% [95%CI: 75-87] vs. 66% [95%CI: 59-74] at 5 years; p<0.001) and disease-free survival (DFS; 72% [95%CI: 65-79] vs. 59%[95%CI: 52-68]; p=0.0004)).These differences were consistent across histological subtypes and resection status.There was no interaction with age.Most of the survival advantage in females was related to lower risks of death and local recurrence, while distant recurrence rates were similar.Conclusions: Female patients had longer OS and DFS than male patients after surgery for primary RPS.Although some differences in tumor subtype and location were observed, these factors do not account for the magnitude of the survival advantage.