Correlation between K-ras gene mutation and clinicopathological characteristics and prognosis of colorectal cancer patients with different primary sites

Abstract

Objective To analyze the correlation between K-ras gene mutation and clinicopathological characteristics and prognosis of colorectal cancer patients with different primary sites. Methods The clinical and pathological records of 69 patients who were pathologically confirmed as colorectal cancer and tested K-ras gene status at Wuxi People's Hospital Affiliated to Nanjing Medical University between May 2007 and August 2017 were adopted. The correlation between clinicopathological characteristics and prognosis of colorectal cancer patients with different primary sites and K-ras gene mutation status were retrospectively analyzed. And the patients were visited to adopt the prognosis data and perform the Kaplan-Meier survival analysis. Results The K-ras mutation rate was 50.7% (35/69), including 40.0% (12/30) in left-side colon cancer, 73.3% (11/15) in right-side colon cancer and 50.0% (12/24) in rectal cancer. The mutation rate of K-ras gene in patients ≥ 60 years old [61.5% (24/39) vs. 36.7% (11/30), χ2 = 4.197, P = 0.041] or serum CA19-9 raising up abnormally was conspicuously high [65.6% (19/29) vs. 37.5% (15/40), χ2 = 5.486, P = 0.019]. Other clinicopathological characteristics, such as gender, lesion location, histological classification, TNM stage, serum CEA expression, clinical features had no correlation with K-ras gene mutation status (all P > 0.05). And no relationship was found between prognosis and overall survival of colorectal cancer patients with different primary sites and K-ras gene mutation status (χ2 = 0.001, P = 0.997; χ2 = 0.583, P = 0.445). In general, the 5-year survival rate of left-side colon cancer patients was highest (76.9%), followed by rectal cancer (69.7%), and right-side colon cancer was lowest (31.3%). The primary site of colorectal cancer was related to the overall survival of patients (χ2 = 11.004, P = 0.004). Conclusions K-ras gene mutation in colorectal cancer is closely related to age and serum CA19-9 levels of the patients. The prognosis of left-side colon cancer is best, rectal cancer second, and right-side colon cancer poorest. Whether K-ras gene mutation is the prognostic factor of colorectal cancer is not clear. Testing the K-ras gene status and serum tumor index expression, distinguish the primary site and age group will provide the theory basis and promote the clinical targeted therapy and improve the survival of colorectal cancer patients. Key words: Intestinal neoplasms; Genes, ras; Pathology, clinical; Prognosis