Relationship of KRAS and PIK3CA gene mutation in colorectal cancer

• Main Authors: Fan-Bao Yao, Qian-Yi Kuang, Xi Fu, Shi-Yao Huang
• Format: Article
• Language: English
• Published: Editorial Board of Journal of Hainan Medical University 2016-05-01
• Series: Journal of Hainan Medical University
• Subjects: KRAS gene; PIK3CA gene; Gene Mutations; Colorectal Cancer; Metastasis; Recurrence
• Online Access: http://www.hnykdxxb.com/PDF/201609/2.pdf
• ISSN: 1007-1237; 1007-1237

Objective: To analyze the relationship between KRAS/PIK3CA gene mutation and clinicopathologic characteristics such as gender, age, tumor location, pathological pattern, histological grade, TNM stage and lymph node metastasis, especially the relationship with distant metastasis of colorectal cancer. Methods: A total of 94 cases of colorectal cancer samples surgically resected in Gastrointestinal Surgery Department of our hospital from January 2012 to August 2015 were collected, DNA was extracted and then KRAS and PIK3CA gene sequencing was carried out; their clinicopathologic characteristics (gender, age, tumor location, pathological pattern, histological grade, TNM stage, lymph node metastasis and distant metastasis) were analyzed, the relationship between KRAS/PIK3CA gene mutation and above factors, especially distant metastasis was analyzed, and statistical analysis processing was conducted; patients received 3-year follow-up, distant metastasis and recurrence were observed, and the number of their cases was counted, statistically analyzed and processed. Results: KRAS gene mutation was not associated with gender, age, tumor location, pathological pattern and histological grade, and significantly associated with distant metastasis, lymph node metastasis and TNM stage; PIK3CA was not associated with gender, age, tumor location, pathological pattern and histological grade, and associated with TNM stage, lymph node metastasis and distant metastasis; 7 cases (7.4%) were with mutation of both KRAS and PIK3CA (double positive), and 55 cases (57.4%) were with no mutation at all (double negative); in double positive cases, 5 cases were with distant metastasis, metastasis rate was 71.4% and higher than that of double negative (16/55, 29.1%), and there were statistical differences; it was found in follow-up that metastasis rate of KRAS mutant type was higher than that of wild type, and differences were statistically significant; recurrence rates of KRAS and PIK3CA mutant type were higher than those of wild type, and differences were statistically significant. Conclusion: KRAS and PIK3CA gene mutation rates in colorectal cancer tissue are associated with TNM stage, lymph node metastasis and distant metastasis, and mutant type is more susceptible to distant metastasis and recurrence than wild type; KRAS and PIK3CA gene mutation may have certain predictive value for distant metastasis and recurrence of colorectal cancer, and have certain guiding significance for judgment of patients’ prognosis.