Tohoku J. Exp. Med., 2014 May, 233(1)

Tumor Sites and Microscopic Indicators Are Independent Prognosis Predictors of Gastrointestinal Stromal Tumors

YIJUN QI,¹ WENDI ZHAO,² ZHENGGUANG WANG,¹ TUANJIE LI¹ and XIANGLING MENG¹

¹Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, P.R. China
²Department of Pathology, Anhui Medical University, Hefei, Anhui, P.R. China

Gastrointestinal stromal tumors (GISTs) are the most common among gastrointestinal mesenchymal tumors, but its prognosis has not been accurately predicted by the current risk stratification guidelines, National Institutes of Health classification. In this study, we evaluated the predictive factors for GIST prognosis in a retrospective analysis of 332 patients. The data collected included tumor sites, including the esophagus, stomach, duodenum, small intestine, and extragastrointestinal sites; tumor size; microscopic indicators for malignant tumor behavior, such as the number of dividing cells, cell necrosis, atypical morphology, and invasion into the muscular or mucous layer; and previously established immunohistochemical indicators, CD117, CD34, and discovered on GIST-1 (DOG-1). No single occurrence of any microscopic indicators correlated with the prognosis of GIST; however, the total number of microscopic indicators was a significant prognostic factor of GIST (P < 0.001). Regarding the tumor sites, the order of prognostic risk (from the lowest to the highest) was as follows: the esophagus, stomach, duodenum, small intestine, extragastrointestinal sites, and colorectum. The association between tumor sites and prognosis was significant (P < 0.001). On the other hand, the expression of CD117 or CD34 was not associated with the risk of GIST. Importantly, 91% of the patients (302/332) showed the expression of DOG-1, and the lack of DOG-1 expression was associated with poor prognosis (P < 0.05). In conclusion, both tumor sites and total number of microscopic indicators are independent risk factors associated with the prognosis of GIST. The lack of DOG-1 expression may be predictive of malignant outcome.

keywords —— Keywords: discovered on gastrointestinal stromal tumor-1; gastrointestinal stromal tumor; microscopic indicator; risk classification; tumor site

© 2014 Tohoku University Medical Press

===============================

Tohoku J. Exp. Med., 2014, 233, 65-72

Correspondence: Xiangling Meng, Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Rd, Hefei, Anhui 230032, P.R. China.

e-mail: xianglingmeng55@sina.com