Survival Rate of Colorectal Cancer Patients Receiving Chemotherapy based on Tumor Location and K-Ras Gene Mutation Status: A Systematic Review

Abstract

Introduction: Colorectal cancer (CRC) is a remarkable global health burden, considering its high morbidity and mortality. For both resectable and unresectable colorectal cancer (CRC), chemotherapy is the first-line option. The survival rate was significantly affected by the location of the tumor and the mutation status of the KRAS gene. This study aimed to systematically synthesize current evidence on how primary tumor location and KRAS mutations influence the survival of colorectal cancer patients receiving chemotherapy.

Methods: We performed a systematic search of the electronic databases with defined inclusion and exclusion criteria. Independent reviews were performed by two reviewers of the literature that was included. Methodological quality of the studies included was evaluated using the Joanna Briggs Institute (JBI) critical appraisal methods. Information was obtained and qualitatively analyzed. The analysis was performed through a qualitative measure. P-value < 0.05 is considered statistically significant.

Results: A total of 11 studies were reviewed. All the studies reviewed reported improved quality of methodology. The qualitative synthesis suggested a trend toward worse survival for patients with right-sided tumors, although some studies reported no statistically significant difference between tumor locations. In contrast, the association between KRAS gene mutations and poorer survival outcomes appeared more consistent across studies. Overall, these findings indicate that KRAS mutations and, to a lesser extent, right-sided tumor location may predict unfavorable outcomes in chemotherapy-treated colorectal cancer patients.

Conclusion: KRAS mutations were linked to poorer survival, while right-sided tumor location showed a less consistent but generally unfavorable trend among chemotherapy-treated colorectal cancer patients.