Impact of periodic endoscopy on incidentally diagnosed gastric gastrointestinal stromal tumors: findings in surgically resected and confirmed lesions.

Background: Although gastric gastrointestinal stromal tumors (GISTs) are usually identified by endoscopic examinations, the diagnostic value of endoscopy has not been fully evaluated. We assessed the diagnostic performance of endoscopy for gastric GISTs according to lesion characteristics. Furthermore, the benefits of periodic endoscopy prior to diagnosis of gastric GISTs were evaluated.
Methods: We reviewed patients who underwent surgery for gastric GISTs at Severance Hospital, Seoul, Korea, between January 2008 and April 2014. In addition, we administered a questionnaire to determine the usage of periodic endoscopic inspection and the period from the penultimate endoscopy to the diagnosis.
Results: Of 174 included patients, 109 (62.4 %) showed intraluminally growing GISTs and 65 (37.4 %) showed extraluminally growing GISTs. The proportions of lesions that were initially diagnosed via endoscopy were 99.1 % for intraluminally growing GISTs and 49.2 % for extraluminally growing GISTs (P < 0.001). In patients with intraluminally growing GISTs, patients who had undergone endoscopy within 3 years prior to the diagnosis showed smaller tumor sizes (P = 0.015) and fewer tumors with ulceration (7.1 vs. 28.4 %, P = 0.021). The proportion of GISTs with a high mitotic index did not differ according to the usage of periodic endoscopy (P = 0.639). In contrast, lesion characteristics of the extraluminally growing GISTs did not differ according to whether an endoscopy was performed within 3 years prior to the diagnosis.
Conclusions: Endoscopic examinations had a limited role in the diagnosis of extraluminally growing GISTs. However, periodic endoscopy was associated with relatively earlier detection of growth in intraluminal gastric GISTs.