Evaluating Malignant Potential of Gastric Adenomas: The Role of Endoscopic Features and Genetic Alterations.

Background and aim: There is no "gold standard" treatment for gastric adenomas due to uncertainty about their malignant potential. We wanted to understand better the factors contributing to their transformation into malignant tumors by analyzing their long-term development, including endoscopic observations and genetic abnormalities.

Methods: A total of 34 gastric tumor specimens from 17 patients were analyzed. All patients initially received a diagnosis of adenoma through a biopsy. Subsequently, eight patients were confirmed to have adenoma, while nine were diagnosed with carcinoma following an endoscopic mucosal dissection. The tumor lesions were isolated using laser-capture microdissection for DNA extraction. Subsequent targeted sequencing of 50 cancer-related genes was performed. The resultant data were compared with the patient's clinical records, and the endoscopic findings, including tumor color, microsurface pattern, and microvascular pattern, were observed.

Results: In ESD specimens, the most frequently detected gene alterations were in APC (53%), KRAS (18%), TP53 (12%), and FBXW (12%). There were no differences in frequency between final diagnoses, although there was a tendency to detect more gene alterations in cases ultimately diagnosed with adenoma (p = 0.05). Conversely, endoscopic findings of reddish/same color rate (p < 0.01) and MSP/MVP irregular rate (p < 0.05) were higher in cases with a final carcinoma diagnosis at ESD.

Conclusions: Color and magnifying NBI during endoscopy help predict malignant transformation when patients are followed up for adenomas.