RT Journal Article SR Electronic T1 Poor Efficacy of Postoperative Radiotherapy in Infiltrative High-grade Soft Tissue Sarcomas JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 4027 OP 4032 DO 10.21873/anticanres.15202 VO 41 IS 8 A1 HIDEYUKI KINOSHITA A1 TAKESHI ISHII A1 HIROTO KAMODA A1 YOKO HAGIWARA A1 TOSHINORI TSUKANISHI A1 MASAHIRO INOUE A1 TORU UETA A1 SEIJI OHTORI A1 TSUKASA YONEMOTO YR 2021 UL http://ar.iiarjournals.org/content/41/8/4027.abstract AB Background/Aim: We aimed to investigate the effectiveness of postoperative radiotherapy (RT) on local recurrence-free survival (LRFS) in high-grade infiltrative soft tissue sarcomas (STSs) and determine its prognostic factors. Patients and Methods: This was a retrospective cohort study and included 132 patients with high-grade STSs. Patients were divided into two groups: Group RT (n=48) who underwent postoperative RT and Group No-RT (n=84) who underwent only surgery. We analysed 5-year LRFS and its prognostic factors between these groups. Furthermore, 5-year LRFS in infiltrative and non-infiltrative STSs were evaluated. Results: Five-year LRFS was not significantly different in Group RT (83.6%) and Group No-RT (79.6%) (p=0.698). Overall, significant prognostic factors influencing LRFS were age at diagnosis (p=0.02) and tumour growth pattern (p=0.04). Postoperative RT was less effective in the infiltrative than in non-infiltrative pattern of STSs. Conclusion: Postoperative RT does not influence local recurrence outcomes in infiltrative STSs.