Leiomyosarcoma of the uterus: A clinicopathologic multicenter study of 71 cases

Objective. The aim of this study was to evaluate the behavior of uterine le iomyosarcomas in relation to their clinical and pathologic features and to identify possible prognostic factors. Methods. Seventy-one patients with histologically proven uterine leiomyosar coma were included in the analysis. Leiomyosarcomas were defined as uterine smooth-muscle tumors with five or more mitoses per 10 high-power fields an d cytologic atypia. Cox proportional hazards regression model was used to i dentify independent prognostic factors. Results. The median follow-up time was 108 months; 5-year overall survival rate was 65%. Evaluating the correlation between several clinicopathologic parameters, tumors with vascular space involvement had a statistically sign ificantly higher stage than tumors without vasular space involvement (P = 0 .015). In a univariate Cox model early tumor stage (P < 0.0001), age <50 ye ars (P < 0.0001), low mitotic count (P = 0.05), and the absence of vascular space involvement (P < 0.0005) were associated with good prognosis. In a m ultivariate analysis age (P = 0.002), tumor stage (P = 0.004), vascular spa ce involvement (P = 0.003), and mitotic count in stage I tumors (P = 0.002) were found to be independent parameters for good prognosis in patients wit h uterine leiomyosarcoma. Conclusion. Early tumor stage, age <50 years, and absence of vascular space involvement were independently associated with good prognosis, Mitotic cou nt was detected to be a strong prognostic parameter in early tumor stage, b ut failed to act as an independent prognostic parameter in patients with tu mor stage II-IV disease. (C) 1999 Academic Press.