A Molecular Alteration Situations of KRAS, NEAS, BRAF, PIK3C and PTEN Loss in Colorectal Adenocarcinoma at Can The Oncology Hospital

摘要

Aim To determine the characteristics of KRAS, NRAS, BRAF, PIK3CA gene mutation and loss of PTEN expression in colorectal adenocarcinoma in Can Tho Oncology Hospital. Materials and methods A cross-sectional study included 50 cases of colorectal adenocarcinoma were diagnosed and treated at Can Tho Oncology Hospital. KRAS, NRAS, BRAF, PIK3CA mutations identified by Sanger DNA sequencing as well as evaluating the loss of PTEN protein expressed by MHC. Results and discussion Among the 50 colorectal cancer patients, we detected 17 (34%) mutations in the KRAS, NRAS (0%), BRAF 1(2%) and PIK3CA 3(6%), all of which were point mutations. Mutation frequencies at codon 12 and codon 13 were 26%. Only one patient harboured a point mutation at codon 10. The KRAS mutation frequency was significantly higher in the rectum than in the colon (26% versus 8%, p = 0.022). Other clinic-pathological features, such as gender, histological type, and grade, TNM stage, showed no positive relationship with KRAS gene mutations. The PIK3CA mutation frequency was significantly higher in the <50 years patients or female than in the group > 50 years (6% versus 0%) with p = 0.042; p = 0.036 respectively. The incidence of PTEN loss was 14%. Loss of PTEN expression, relative to regional lymph nodes metastatic and distant metastasis was statistically significant. Conclusion The KRAS mutation rates of colorectal adenocarcinoma patients in Can Tho Oncology Hospital were 34%. KRAS mutation associated with tumor location. PIK3CA mutation associated with age and gender. In 50 cases, none of NRAS mutations detected. K601E BRAF mutation is also one of several situations that cause over-activation of the BRAF protein. The rate of PTEN loss was 14% and about regional and distant metastasis.