P-283 Prognostic factors in the evaluation of stage II/III squamous cell carcinoma of the anus treated with chemoradiation

Abstract

Squamous cell carcinoma of the anus (SCCA) is a rare disease. Studied prognostic factors for survival in anal cancer include male sex, positive lymph node, and primary tumour size >5 cm. We aimed to perform an exploratory analysis of prognostic factors for overall survival in patients (pts) who underwent radical chemoradiation (CRT) with a standard-of-care regimen including fluoropyrimidine and mytomicin C (MMC). A retrospective analysis of stage II-III SCCA pts with PS ECOG 0-1 treated with CRT using fluoropyrimidine and MMC at a single Portuguese Oncology Unit between January 1st, 2010 and October 30th, 2020 was performed. Data cut-off was March 20th 2021. Data was obtained from pts' clinical files and analysed with SPSSv26.0, with overall survival (OS) estimation using the Kaplan-Meier method. Twenty-three pts were selected, with median (med) age of 66 years (y) [30-81], 39.1% being female. Regarding initial staging, 21.7% had stage II, 17.4% stage IIIA, and 60.9% stage IIIB. 78.3% had lymph node disease; 47.8% had tumours > 5 cm in size; 56.5% had ulcerated lesions (skin or endoscopically); 39.1% were active smokers. Med follow-up was 4 y; the OS at 4y was about 75%, with an estimated med OS 8.09 y [6.0-10.2]. We stratified our sample per LDH > 250 UI/L, haemoglobin (Hb) 5 cm, and being male. The estimated OS with LDH > 250 vs 5 cm vs 12.0 g/dL was 6.20 vs 9.85 y (p 2.85 had 6.63 vs 9.07 y (p=0.206)). For PLR, it was 151.5, but without a significant tendency (151.5 7.58 vs 8.28 y, p=0.627). In our analysis, we found a statistically significant tendency for better survival in pts with stage II-III SCCA CRT treated with Hb > 12.0 g/dL, LDH < 250 UI/L, no active smoking, and female sex. We also found an interesting tendency for better OS with a high NLR, though this was not statistically significant. These prognostic factors can be used as a tool to eventually increment the treatment aggressiveness in pts with worse prognosis.