Clinical significance of surgery for gastric submucosal tumours with size enlargement during watchful waiting period

Background The true impact of surgery for small, asymptomatic and biopsy-negative gastric submucosal tumours (SMTs) with size enlargement during 'watchful waiting' period has not been fully understood. Methods From 2005 to 2012, 100 patients with gastric SMTs underwent surgery. Twenty-three of them with size enlargement during observation period were enrolled in the retrospective analysis. Data included clinicopathologic findings, genetic findings, operative outcomes and prognoses. Results All patients (13 males, 10 females), with median age of 54 (41-71), had their lesions detected by routine health check-up (n = 21) or incidentally (2). The tumours were 1.8 (0.5-4.0) cm in size at their initial detection, and enlarged up to 3.2 (2.0-7.0) cm at the operation during 63.0 (14.6-233.7) months. As surgical procedure, laparoscopic partial gastrectomy accounted for the majority (78.3%). Histologic examination revealed gastrointestinal stromal tumour (GIST) (21) and schwannoma (2). Although 16 out of 21 GISTs were categorised into 'Very low' (1), and 'Low' (13) risk according to Fletcher's classification, 'Intermediate' (5) and 'High' (2) risk were identified in the series. No recurrences/metastases were noted in 23.2 (0.9-87) months of postoperative follow-up. Conclusion Our study revealed the existence of high mitotic GISTs in asymptomatic, small gastric SMTs with size enlargement, and laparoscopic surgery was safely applied to majority of those cases. Prompt surgical intervention should therefore be considered for those lesions.