P-286 Clinicopathological profile and outcomes in locally advanced rectal cancer with major pathological response following neoadjuvant therapy

The standard management of locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (CRT) combined with carcinologic resection. This approach has resulted in down-sizing and down-staging the tumour. A major pathological response (ypT0-1 N0) associated better survival, less local recurrence, distant failure. We aimed to describe clinicopathological features key determinants outcome among Tunisian patients response. conducted a retrospective study including diagnosed medical oncology department at Salah Azaiz Institute Tunisia over six-year-period (January 2015 December 2021) who underwent long course CRT. categorized them based on histological distinguished those One hundred five were included. Thirty-two had (30.4%). In this category, mean age diagnosis was 57.8 years. sex-ratio 0.6 female predominance. Preoperative carcinoembryonic antigen (CEA) level elevated 4 (12.5%). According pelvic magnetic resonance imaging (MRI) assessment, tumor staged as cT4 6 (19%) most stage III RC (75%). Median radiation dose 50Gy. median time from therapy surgery 11.7 weeks. Anterior resection abdominoperineal amputation performed 62.5% 37.5% respectively. Twenty complete (ypT0N0) 12 showed nearly (ypT1N0). Adjuvant CT administered 40% cases. After follow-up 51 months, recurrence noted 3 patients. disease free survival (DFS) rate 5 years 93.6%. univariate analysis, factors PFS were: < 70 (p=0.019), gender (p=0.042), endoscopic size 40mm (p=0.007), normal initial CEA (p=0.005), non staging (p=0.026). multivariate only remains an independent prognostic factor DFS (p=0.03). Overall 85.4%. for OS 40 mm (p=0.04), (p=0.03), (p=0.030). our study, 85% during follow-up. Multivariate analysis identified tumour size, preoperative clinical TNM that affect survival.