ESTRO 2022 - Abstract Book

S1154

Abstract book

ESTRO 2022

significant inter-relation(P=0.013). There were no significant differences between SOX2/Oct4 expression and clinico- pathological parameters, except TIL(P=0.003) and necrosis(P=0.024) with SOX2 expression. At a median follow-up of 36 months, the three-year OS was 60% in the low SOX2 expression group(Mean(95% CI) 37(33-42) months) and 53% in the high SOX2 expression group(Mean (95% CI) 36(31-42) months)(P=0.856). The three-year OS was 54 % for low Oct4 expression and 100% for high Oct4 expression(P=0.114). On Cox regression, SOX2 expression(P=0.043) and morphology(P=0.032) were the only variables significantly associated with OS. The three-year DFS was 65% in the low SOX2 expression group(Mean (95% CI) 32(27-38) months) and 50% in the high SOX2 expression group(Mean (CI) 25(18-32) months)(P=0.259). The three-year DFS was 59 % for low Oct4 expression and 75% for high Oct4 expression(P=0.598). On Cox regression, SOX2 expression was the only variable significantly associated with DFS(P=0.038).

Conclusion Our study demonstrated a trend towards improved OS and DFS with low SOX2 and high Oct4 expression. Future research may focus on validating these biomarkers prospectively in a larger population and intensifying radiotherapy treatment in adverse subgroups, reducing overall treatment time or escalating dose.

PO-1360 Nutritional and inflammatory status as predictive biomarkers in oligorecurrent PCa (RADIOSA TRIAL)

M. Zaffaroni 1 , G. Marvaso 2 , G. Corrao 2 , S. Gandini 3 , M. Pepa 1 , M.G. Vincini 1 , D. Zerini 1 , F.M. Castronovo 1 , M. Augugliaro 1 , F. Cattani 4 , F.A. Mistretta 5 , S. Luzzago 5 , G. Musi 6 , S. Alessi 7 , C. Fodor 1 , G. Petralia 8 , G. Pravettoni 9 , O. De Cobelli 6 , R. Orecchia 10 , B.A. Jereczek-Fossa 2 1 IEO, European Institute of Oncology IRCCS, Division of Radiation Oncology, Milan, Italy; 2 IEO, European Institute of Oncology IRCCS; University of Milan, Division of Radiation Oncology; Department of Oncology and Hematoncology, Milan, Italy; 3 IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Milan, Italy; 4 IEO, European