Image analysis technology has also significantly improved. In this study, we use digital image morphometry to analyze a large series of well-characterized GISTs with accessible clinical and histologic information. We explore the correlation of morphometric factors with clinical method and morphologic characteristics of the patients, and the potential prognostic value of these morphometric factors in univariate and in multivariate analyses including established prognostic factors in GISTs. Materials and Methods Patients and Samples The study material consisted of selected tissue blocks from the archives of pathology departments throughout Norway. Cases were selected by evaluating the records of the Cancer Registry of Norway for mesenchymal tumors and poorly differentiated carcinomas in the gastrointestinal tract over a period of 30 years (1973�C2002).
A total of 3672 reports were evaluated, and all reports with clear evidence of origin of tumor not being mesenchymal were discarded (based on the results of immunohistochemical staining and other methods reported at the time of primary diagnosis). A total of 1192 cases of candidate mesenchymal tumors were identified, and slides and blocks from all these cases were requested. The material was located in all of the 20 pathology departments in Norway. From two hospitals, we received no material, which constituted 92 cases. In 231 cases, no blocks were found or the blocks did not contain enough material for further study. From the archives of the Department of Pathology at the University Hospital of Northern Norway, an additional 64 cases of possible mesenchymal tumors were retrieved.
New slides of the remaining 933 cases were made and stained with hematoxylin and eosin (H&E) and histologically reexamined by gastrointestinal (SES) and mesenchymal tumor (TON) subspecialty pathologists. This excluded an additional 159 cases from the study because they were almost certainly not mesenchymal tumors (based on the H&E stain) but rather carcinomas or lymphomas. Seven hundred seventy-four cases were evaluated as representing true mesenchymal tumors of the gastrointestinal tract, but for making tissue microarrays (TMAs), another 68 cases lacked sufficient material for the required duplicate core extractions (blocks containing only small bite or core biopsies). The 706 remaining cases were assembled into five TMAs.
Only eight patients were treated with STI-571 (Glivec; Novartis, Basel, Switzerland), because this cohort largely predates the use of this drug. The Regional Committee for Medical Research Ethics, Northern Norway, approved the study. Construction of Tissue Microarrays The slide with representative, Anacetrapib viable tumor was selected from each case and coupled to the corresponding formalin-fixed paraffin-embedded block. Duplicate 0.