title: Prognosis of gastrointestinal smooth-muscle (stromal) tumors: dependence on anatomic site.
abstract: Although the significance of various prognostic factors, such as tumor size and mitotic index (MI), has been well established for smooth-muscle tumors of the stomach, the significance of these factors in other sites is less well defined. We studied 1004 patients with gastrointestinal smooth-muscle tumors for whom vital status could be determined. The average MI and tumor size varied significantly among the five major sites examined: esophagus (53 cases), stomach (524 cases), small bowel 252 cases), colon/rectum (108 cases), and omentum/mesentery/peritoneum (67 cases). There was a significant difference in site-specific survival (p = 0.001), with 10-year survival varying between 50% and 70%. Multivariate analysis demonstrated tumor location (p = 0.0320), size (p = 0.0003), MI (p < 0.0001), and patient age (p < 0.0001) to each carry independent prognostic value. The significance of MI was highly site dependent. Separation of survival curves for the stomach, using a threshold for analysis of either 5 or 10 mitotic figures/50 high-power fields, was very good. In contrast, small-bowel tumors showed little separation between survival curves, regardless of whether a threshold of 1, 5, or 10 mitotic figures MF/50 high-power fields was used to distinguish groups. In no site were tumor size and MI alone sufficient to provide an accurate long-term prediction of prognosis. Although tumor location, size, MI, and age have independent value in predicting the prognosis of patients with gastrointestinal smooth-muscle tumors, better methods are still required to accurately predict clinical course.
authors.affiliation: Department of Cellular Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA.
authors.forename: T S
authors.initials: TS
authors.lastname: Emory
authors.forename: L H
authors.initials: LH
authors.lastname: Sobin
authors.forename: L
authors.initials: L
authors.lastname: Lukes
authors.forename: D H
authors.initials: DH
authors.lastname: Lee
authors.forename: T J
authors.initials: TJ
authors.lastname: O'Leary
mesh_terms: D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000401:mortality / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018235:Smooth Muscle Tumor / Q000401:mortality / Q000473:pathology*; D017154:Stromal Cells / Q000473:pathology*; D016019:Survival Analysis; D015996:Survival Rate