Background: The significance of Kirsten rat sarcoma viral oncogene (KRAS) mutation in colorectal cancer (CRC) is well established; yet, its association with KRAS expression and prognosis warrants further investigation. While high KRAS expression is commonly linked with poorer prognosis in other cancers, its role in CRC remains relatively understudied.
Objective: To explore the correlation between KRAS expression, KRAS status, prognosis, and tumor-infiltrating T lymphocyte density in CRC.
Design: Single-center retrospective study.
Methods: Conducted between 2010 and 2020, this study utilized tumor samples to assess KRAS expression and quantify CD3+/CD8+ T lymphocytes. The Cox proportional hazards model and linear regression analysis were employed to examine the relationship between KRAS expression, prognosis, and tumor-infiltrating T lymphocytes.
Results: This study included 265 CRC patients who underwent radical surgery. No significant association was observed between KRAS expression and KRAS status (p > 0.05). High KRAS expression was associated with poorer overall survival and disease-free survival (p < 0.05). Subgroup analysis revealed that high KRAS expression remained indicative of a worse prognosis in the group with mismatch repair-deficient (dMMR) and KRAS mutant type (p < 0.05). Multivariate analysis confirmed KRAS expression as an unfavorable prognostic factor (p < 0.05). However, the significance of KRAS expression was lost in the dMMR and KRAS mutant-type group regarding overall survival (p > 0.05). Notably, KRAS expression showed a negative correlation with the density of CD8+ T lymphocytes in tumor tissue (p < 0.05), a finding also observed in the dMMR group (p < 0.05).
Conclusion: No association was found between KRAS expression and KRAS mutation status in CRC. Higher KRAS expression was indicative of poorer prognosis for CRC patients, except for those with proficient mismatch repair and KRAS wild type. In addition, in patients with dMMR, KRAS expression was associated with a lower density of CD8+ T lymphocytes in tumor tissue.
Keywords: KRAS expression; colorectal cancer; prognosis; tumor-infiltrated T lymphocytes.
Exploring the link between KRAS gene expression and outcomes in colorectal cancer patients: impact on survival, mutation status, and T lymphocyte levels 1. KRAS gene: A gene that, when mutated, can lead to the development and growth of colorectal cancer. The KRAS gene is part of a family of genes that help control cell growth and death. 2. T lymphocytes: A type of immune cell that plays a crucial role in the body's defense against infections and cancer. They can identify and kill cancer cells. 3. The study found that the level of activity of the KRAS gene in colorectal cancer patients did not change based on whether the KRAS gene was mutated or what type of mutation it had. 4. For patients with a specific type of colorectal cancer (dMMR) and those with mutations in the KRAS gene, high levels of KRAS gene activity were linked to a poorer outlook. Essentially, these patients had a harder time fighting the disease, and KRAS gene activity served as a warning sign for more challenging outcomes. 5. In patients with dMMR colorectal cancer, higher KRAS gene activity was associated with fewer CD8+ T lymphocytes in the tumor. CD8+ T lymphocytes are crucial immune cells that help fight cancer by attacking cancer cells. This means that in these patients, the body's natural defense against the tumor was weaker.
© The Author(s), 2024.