P-417 Impact of Tumor Location on Clinicohistological Profile and Oncological Outcomes in Tunisian Population

Sidedness of colorectal cancer (CRC) can reveal different presentation, molecular alteration, histology, and outcome. Left-sided CRC are known to have a better prognosis in term of progression and recurrent disease.We aimed to evaluate the impact of tumor site not only on epidemiological and clinipathological features but also on oncological outcome in Tunsian population. We retrospectively analyzed a cohort of 111 patients, treated for localized cancer at Farhat Hached Hospital in Tunisia, over a 13-year-periode (January 2006-December 2018). Clinico-pathological characteristics and Kaplan Meier survival were compared between two groups of LCC and RCC patients. We found 65 patients with LCC (58.5%) and 46 patients with RCC (41.4%). No significant differences were identified between the two groups in sex, obesity, comorbidities or serum CEA level. The LCC group had higher median age (68 years vs 60.5 years p=0.006), more complicated forms revealing the tumor (55,4% vs 37% ; p=0,09) and more acute intestinal obstruction (AIO) (23% VS 6.5% ; p=0.02). Compared with LCC group, RCC group had more mucinous type (p=0,071), higher parietal infiltration depth (T3-T4)(80.4% vs 61.5% ; p=0.033), higher median of resected lymph nodes ( 17 vs 15 ; p=0.028), lower rmedian of hemoglobine rate ( 9.6 g/dl vs 11.2g/dl ; p=0.001) and more transfusion rate (p=0.002). The median time to reccurence was not significantly longer in RCC (32 months) versus LCC ( 20 months), p=0.864. The recurrence-free survival (RFS) rates at 5 years were 80% for RCC and at 79.8% for LCC (p=0.956). Tumor sidedness did significantly affect overall survival (OS) only in univariate analysis. In our study patients with LCC were older and the tumor in this site was more frequently revealed by a complicatedform, especially AIO. RCC group needed more transfusions, showed more mucinous type, greater parietal infiltration and a highernumber of resectedlymphnodes. Tumor location did not impact oncological outcome in Tunisian population.