173 Performance of PERSARC as Prognostic Tool of Extremity Soft Tissue Sarcoma

Abstract

Abstract Aim To review extremity soft tissue sarcoma (ESTS) in MSK sarcoma unit in Glasgow Royal Infirmary. To assess reliability of PERSARC nomogram in estimating outcomes of FNCLCC Grade II and III ESTS. Method A retrospective study of 72 patients with primary ESTS, treated surgically at GRI from 2010-2015 was performed. Patients were followed up as per local sarcoma protocol up to 10 years. Overall survival (OS), Local recurrence (LR) and Distant metastasis (DM) at 3 years and 5 years post-op were calculated and PERSARC nomogram was used to estimate predicted OS, LR and DM at 3 years and 5 years post-op. The reliability of PERSARC to estimate ESTS outcomes was assessed using discrimination and calibration. Concordance index was used to assess discrimination. Calibration plot was used to assess calibration. Results Observed 5-year OS, LR and DM were 77.78%, 12.5% and 27.77% respectively. Concordance indices for 3-year OS, LR and DM were 0.82, 0.68 and 0.70 respectively. Concordance indices for 5-year OS, LR and DM were 0.77, 0.69 and 0.66 respectively. Calibration plot showed PERSARC underestimated 3-year and 5-year OS. Calibration plot showed good calibration for 3-year and 5-year LR and DM. Conclusions PERSARC nomogram showed good discriminative ability for 3-year OS, 3-year DM, and 5-year OS as the concordance indices were >0.7 and good calibration for 3-year and 5-year LR and DM. PERSARC could be beneficial to guide shared decision making between patients and healthcare professionals, leading to focused and personalised care for patients with ESTS.