Concurrent gastrointestinal stromal tumor and digestive tract carcinoma: a single institution experience in China.

The aim of this study was to review the clinicopathological characteristics and survival outcomes of patients with concurrent gastrointestinal stromal tumor (GIST) and digestive tract carcinoma. Among 585 patients diagnosed with GIST from January 2005 to July 2014, 32 (5.5%) had synchronous digestive tract carcinoma, including 19 (59.4%) men and 13 (40.6%) women. The median age was 64 years (range, 43-84). GIST was located in the stomach (n=24), small intestine (n=6), duodenum (n=1) and retroperitoneum (n=1). GISTs were intra- or postoperatively discovered (n=28) or preoperatively identified (n=4). The tumor size was less than 10 mm (microGIST) in 23 (71.9%) GIST patients. The preoperatively identified GIST subgroup showed a significantly larger tumor size, more mitotic figures and a higher risk grade than the intra- or postoperatively identified GIST subgroup. Concurrent digestive tract carcinomas were most frequently located in the stomach (24 cases, 75%). The other involved sites were the esophagus (n=5), duodenum (n=2) and colon (n=1). With a median follow-up of 32 months (range, 9-80), 24 patients were alive without evidence of disease, 6 patients had died of carcinoma progression, 1 patient had died from an accident, and 1 patient experienced GIST metastasis to the liver. In summary, we discovered that 5.5% of GIST patients also developed a concurrent digestive tract carcinoma in a series of 585 GIST cases. The majority of GISTs are incidentally identified microGISTs. The concurrent carcinoma seems to have a greater unfavorable effect on prognosis than the GIST. However, for a GIST that is identified preoperatively with a high risk of progression, adjuvant therapy is warranted.