CLINICAL, ENDOSCOPIC, HISTOPATHOLOGICAL, AND KRAS MUTATION CHARACTERISTICS IN NON-POLYPOID COLORECTAL CANCER PATIENTS AT CAN THO UNIVERSITY OF MEDICINE AND PHARMACY HOSPITAL

Non-polypoid colorectal cancer is a distinct subtype of colorectal malignancy that is often associated with delayed detection and unfavorable clinical characteristics. A cross-sectional descriptive study was conducted on 56 patients diagnosed with non-polypoid colorectal cancer at Can Tho University of Medicine and Pharmacy Hospital from 2024 to 2026. Clinical manifestations, endoscopic findings, histopathological characteristics, and KRAS mutation status were analyzed, and KRAS exon 2 sequencing was performed to identify mutation subtypes. The mean patient age was 60.0 ± 11.37 years, with females accounting for 58.9% of cases. Hematochezia (58.9%) and abdominal pain (42.9%) were the most common symptoms. Most tumors were located in the rectum and presented as fungating lesions, while grade 2 adenocarcinoma was the predominant histopathological type (91.1%). KRAS mutations were detected in 5.4% of patients, with all mutations occurring at codon 12 of exon 2. Among these, G12A was the most common mutation subtype (66.7%), followed by G12D (33.3%). In conclusion, non-polypoid colorectal cancer was characterized by predominant rectal involvement, fungating morphology, and a low frequency of KRAS exon 2 mutations.