The examination of appropriate surveillance after resection of GIST from 115 recurrent patients.

Abstract

12 Background: Previous studies have proposed some risk classifications and contributed to the prediction of the prognosis in gastrointestinal stromal tumor (GIST) patients after resection. However, optimal postoperative surveillance has not been established yet. We investigated the characteristics of GIST patients who developed recurrence after resection to establish optimal postoperative surveillance for recurrence. Methods: Between July 1978 and November 2014, 115 patients developed recurrence after macroscopically complete resection for primary GIST. We investigated the clinicopathological factors, time to recurrence (TTR) and first recurrence sites to determine the optimal duration and methods of surveillance. We also compared the characteristics between the two subgroups with TTR ≤ 5 years or > 5 years. Results: The median age was 60 (15-84) years old and 62% of the patients were men. The most common primary tumor site was the stomach (39%), followed by the small intestine (37%), duodenum (11%), large intestine (10%) and esophagus (2%). The median tumor size was 8.5 (1.5-30.0) cm and the median mitotic count was 4 (0-165) /50 HPF. The site of recurrence was liver (57%), followed by peritoneum (48%), local (21%), bone (4%) and lymph node (2%). Almost all patients, except one lung recurrence by esophageal GIST, showed primarily recurrence in the abdominal site. The median period of recurrence after resection 21 (1-172) months and 12% of the recurrence occurred over 5 years. We divided the two groups by the period of recurrence, Early-group (E) ( ≤ 5 years), and Late-group (L) ( > 5 years). Comparing the two groups, E group showed a smaller size (median, 3.5 vs. 9.0 cm) (p < 0.001) and a lower risk classification (p < 0.001) than L group. Although liver recurrence was the most frequent in E group (60 %), local recurrence was the most frequent in L group (43 %). Conclusions: Twelve percent of the recurrence occurred over 5 years, and almost all patients showed primarily recurrence within the abdomen. This may indicate that postoperative surveillance after complete resection for primary GIST is recommended over 5 years by abdominal examination.