Clinicopathological and immunohistochemical analysis of gastrointestinal stromal tumor

The term "gastrointestinal stromal tumor (GIST)" has been applied to mesenchymal tumors that were positive for c-kit and CD34. In this study, we investigated the clinicopathologic features of GIST, and whether these molecular markers, especially integrins, p53, Ki-67, and proliferating cell nuclear antigen (PCNA) identified by immunohistochemical approaches may reveal the malignancy of GIST. Until December 2002, 23 patients with GIST underwent operation at Nagoya City University Hospital, Japan. We immunohistochemically analyzed the expression of these molecular markers in 25 tumor specimens of GIST. The immunohistochemical analyses showed the staining of p53 and Ki-67 related to the size of tumors. Expression of a5 and a6-integrin subunits increases the tendency of getting strong in association with the tumor size. Our present results indicate that a5 and a6-integrin expression can be a more sensitive malignant marker in GIST.