Uterine sarcomas in Norway. A histopathological and prognostic survey of a total population from 1970 to 2000 including 419 patients

To determine the frequency and survival of the various types of uterine sarcoma in the total population of Norway and evaluate histopathological prognostic factors in order to identify risk groups. Histopathological review of all uterine sarcoma cases reported to the Norwegian Cancer Registry during 1970-2000 was undertaken. Survival dates were provided by The Cancer Registry. Kaplan-Meier survival curves were generated. The log rank test was used for univariate analysis and a Cox proportional hazards regression model for multivariate evaluation of survival. Stage of disease was the most important prognostic factor for all tumour types. Tumour size and the mitotic index (MI) were significant prognostic factors (P < 0.0001) in leiomyosarcomas confined to the uterus and allowed for separation into three risk groups with marked differences in prognosis. The prognosis of endometrial stromal sarcomas confined to the uterus was related to MI (P < 0.0001) and tumour cell necrosis (P < 0.004). Combining these parameters allowed for separation into three risk groups with marked difference in prognosis. In adenosarcomas, tumour cell necrosis was the only significant prognostic factor. There are marked differences in survival between uterine sarcoma types. Leiomyosarcomas and endometrial stromal sarcomas can be divided into different groups.