Clinical Implication of KRAS Mutation Variants in Patients With Resected Colon Cancer

Genetic Profiling and Survival Outcomes in Romanian Colorectal Cancer Patients

BACKGROUND

The increasing incidence of colorectal cancer is one of the most frequently addressed medical topics worldwide. It represents the third most commonly diagnosed cancer in both men and women globally, with significant implications for public health. Mortality for this type of malignancy remains high, second only to lung cancer. Given their clinical relevance, the identification and understanding of KRAS and BRAF mutations have become crucial components of personalized medicine approaches in colorectal cancer. Hence, our desire is to carry out a research that analyzes the impact of these mutations in terms of survival and mortality on patients diagnosed with colorectal cancer.

METHODS

We conducted a retrospective study spanning from 2018 to 2022, which involved 118 patients diagnosed with colorectal cancer. The patients were selected from the databases of the Oradea County Emergency Clinical Hospital and Pelican Oradea Hospital. Genetic testing was performed at the "Resident Laboratory" clinic. Subsequently, patients were divided into two groups of equal size based on the presence or absence of mutations.

RESULTS

The survival rate one year after the diagnosis of colorectal cancer is 84.74% (N=50/59) for the mutant group versus 67.96% (N=40/59) for the wild-type group. The survival rate at five years from the diagnosis of colorectal cancer is 25.93% (N=15/59) for patients with wild-type tumors compared to 33.54% (N=20/59) for patients with tumors with mutant status (p=0.483, HR=1.153, CI 95% 0.7661-1.735). The five-year survival rate, depending on the mutation present, highlights the fact that the average overall survival for those with the KRAS mutation is 38.6 months (CI 95% 35.22-41.97) and for those with the BRAF mutation is 8.3 months (CI 95% 5.42-11.17) (p=0.039). The mortality rate for mutant KRAS is 44.89% (N=22/50), while for those with mutant BRAF, it is 100% (N=6/6).

CONCLUSIONS

We observed no statistically significant difference in overall survival rate and disease-free interval between the two studied groups, but the overall survival was better for those with mutations present (38.64 months versus 31.07 months for wild-type tumors). The mortality rate is higher among tumors with wild-type status (p=0.005), in the first year after the diagnosis of colorectal cancer. The BRAF mutation confers a much worse prognosis than the KRAS mutation, from both the survival analysis and the mortality rate.

Integrated Decision-Making in the Treatment of Colon-Rectal Cancer: The Case of KRAS-Mutated Tumors

In recent years, precision medicine has taken an increasing place in various branches of medical oncology, including colorectal cancer. Among the potentially relevant mutations for this cancer is the KRAS mutation, initially defined as "untargetable"; today, we see the birth of new molecules that target one of the variants of the KRAS mutation, KRAS G12C, having a significant impact on the therapeutic options for other malignancies, such as metastatic lung cancer. This fundamental step forward has stimulated scientific research on other potential targets of KRAS, both indirect and direct, and combination treatments aiming to overcome the mechanisms of resistance to these drugs that decrease in efficacy in colorectal cancer. What was once a negative predictive marker of response to anti-EGFR drugs today has become a potential target for targeted treatments. In turn, the prognostic role of the mutation has become extremely interesting, making it a potentially useful element in therapeutic decision-making, not only regarding oncological treatments but also in a more complex and complete manner within a global vision of the patient, involving other figures on the multidisciplinary team, such as surgeons, radiotherapists, and interventional radiologists.