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

The aim of this study was to evaluate the behavior of uterine leiomyosarcomas in relation to their clinical and pathologic features and to identify possible prognostic factors.

Seventy-one patients with histologically proven uterine leiomyosarcoma were included in the analysis. Leiomyosarcomas were defined as uterine smooth-muscle tumors with five or more mitoses per 10 high-power fields and cytologic atypia. Cox proportional hazards regression model was used to identify independent prognostic factors.

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 significantly higher stage than tumors without vasular space involvement (P = 0.015). In a univariate Cox model early tumor stage (P < 0.0001), age <50 years (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 multivariate analysis age (P = 0.002), tumor stage (P = 0.004), vascular space 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 with uterine leiomyosarcoma.

Early tumor stage, age <50 years, and absence of vascular space involvement were independently associated with good prognosis. Mitotic count was detected to be a strong prognostic parameter in early tumor stage, but failed to act as an independent prognostic parameter in patients with tumor stage II-IV disease.