The natural history of imatinib-naive GIST: A retrospective analysis of 929 cases with long-term follow-up

Autor: Carlo Capella, A. P. Dei Tos, Paola Amore, Luca Messerini, Gianluigi Arrigoni, Italo Bearzi, Guido Mazzoleni, Paolo G. Casali, Sabrina Rossi, Aurelio Sonzogni
Rok vydání: 2009
Předmět:
Zdroj: Journal of Clinical Oncology. 27:10555-10555
ISSN: 1527-7755
0732-183X
DOI: 10.1200/jco.2009.27.15_suppl.10555
Popis: 10555 Background: GIST represent a rare form of malignancy and one of best paradigms of molecularly targeted therapy. While the natural history of GIST following treatment with tyrosine kinase inhibitors is relatively well known, most information on imatinib naïve GIST are drawn form either small series or larger studies with possible referral bias. Methods: 1,021 GIST diagnosed between 1980 and 2000 were retrieved from the archives of 35 Departments of Pathology throughout Italy. Pathologic and clinical data were collected. All cases were centrally reviewed and stratified according to NIH 2002 and NCCN 2008 risk classifications. The prognostic meaning of a large set of morphologic and clinical parameters were evaluated by uni- and multi-variate analysis. Informed consent was obtained from all living patients. Results: 92 cases were excluded as non-GIST. Mean and median age were 63 and 65 years. Females were 52%. Disease status at diagnosis was localized in 767 and metastatic in 111 cases. 516 cases were gastric, 229 ileal/jejunal, 26 duodenal, 22 colonic, 28 rectal, and 25 peritoneal/retroperitoneal. NIH 2002 risk classification was available in 917 cases: 121 (13%) very low, 247 (27%) low, 201 (22%) moderate and 348 (38%) high risk. NCCN 2008 risk classification was available in 892 patients. Metastatic sites included liver (5%), peritoneum (10%), lymph-node (1%), skin and soft tissue (0.5%), and lungs (0.2%). Median follow-up was 75 months (range 1–323). Median survival was 88 months. 62% patients died (ED in 46%). Mitotic activity, tumor size and anatomic site correlated with overall survival at multivariate analysis. Striking differences were observed for groups with < 5 mitoses/50HPF, 5 and 10, 10 and 30, and >30. Non gastric GIST exhibit a significant poorer outcome. R2 surgery represents a negative prognostic factor. Conclusions: Mitotic rate has a deep prognostic impact if split in more than two intervals. Setting only two categories may be a limitation of existing prognostic classifications, although the mitotic count is affected by reproducibility issues. Survival curves according to the two main prognostic classifications will be shown. [Table: see text]
Databáze: OpenAIRE