Abstract 1016: Prognostic factors for overall survival, recurrence-free survival, and metastasis-free survival of colon cancer in Morocco

Abstract

Abstract Introduction: Colon cancer is the third most common cancer in Morocco. Its incidence and mortality rate is constantly increasing in this country. This requires the determination of clinical and molecular prognostic factors of CC in our context. Studies indicate that mutations in the RAS genes (KRAS and NRAS) represent such a factor. The aim of this study is to evaluate the prognostic impact of KRAS and NRAS mutations on overall survival (OS), recurrence-free survival (RFS) and metastasis-free survival (MFS) of CC patients. Methods This study involved a series of 210 patients with colon cancer. The clinical and pathological data were obtained from of each patient’s files at the molecular pathology department of the CHU HASSAN II of FES. For molecular data, full RAS status was determined by direct sequencing and Q24 pyrosequencing, after extraction of DNA from formalin-fixed and paraffin-embedded tissue. The evaluation of the relationship between OS, RFS, and MFS and the molecular and clinical factors of the patients was performed by the Kaplan-Meier method and the log-rank test. Results The average age of our patients was 57.5 ± 14.6 years. A slight male predominance was found (52.7%). 39.5% of the cases had a mutation in one of the RAS genes. Mutation of exon 2 of the KRAS gene was the most frequent with a percentage of 36.6%. The NRAS gene was mutated in 2.8% of our patients. The exon 2 mutated tumors were significantly associated with female gender (p=0.04), and left location (p=0.04) compared to the other exons. The mean OS, RFS, and MFS were 100.0%, 92.0% and 92.1% respectively. OS was significantly longer in tumors with KRAS exon 4 mutations compared to tumors with other types of RAS mutations and was also associated with right colon tumors (P=0.001), localized stages I-II (P=0.001), tumors without metastatic nodes (P=0.03), and MSI tumors (P=0.01). For RFS and MFS, localized stage and tumors without metastatic nodes were good prognostic factors (p=0.002, p=0.000). However, the type of mutated exon had no prognostic impact on either. Conclusion In our setting right location, localized stage, absence of metastatic nodes, MSI status and mutated status of exon 4 of the KRAS gene (compared to other exons) are all predictive factors of better overall survival of colon cancer in Morocco. The type of the mutated exon of the RAS genes has no impact on RFS and MFS. Citation Format: Fatima El Agy, Laila Chbani. Prognostic factors for overall survival, recurrence-free survival, and metastasis-free survival of colon cancer in Morocco [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1016.