LEIOMYOSARCOMAS HAVE A POORER PROGNOSIS THAN MIXED MESODERMAL TUMORS WHEN ADJUSTING FOR KNOWN PROGNOSTIC FACTORS - THE RESULT OF A RETROSPECTIVE STUDY OF 423 CASES OF UTERINE SARCOMA

Objective To determine the survival data for the various tumour types of uterine sarcoma and determine the influence of various prognostic factors on survival. Design Retrospective analysis of all uterine sarcoma cases registered in the 15 year period 1967-1981. Setting West Midlands Regional Cancer Registry, serving a catchment area of 2.6 million women. Subjects 423 women registered as having a uterine sarcoma; 367 of these were associated with the two main histological types, leiomyosarcomas (LMS) and mixed mesodermal tumours (MMT). Main outcome measures Duration of survival was taken as the primary endpoint. Results The overall 5-year survival for uterine sarcomas in this series was 31%, with the major prognostic indicator being tumour stage. Survival for mixed mesodermal tumours is similar to other sarcomas despite a tendency towards less differentiation, wider dissemination and a greater age of the patient at diagnosis. Multivariate analysis shows that for cases with similar stage, age and grade, mixed mesodermal tumours have a better prognosis than leiomyosarcomas. Conclusions These results demonstrate the danger of considering each variable in isolation when the relation between variables can lead to spurious significance or lack of significance because of the imbalances in the numbers between groups of prognostic importance. This study underlines the need for an adequate inspection of the intra-abdominal contents at the time of hysterectomy for uterine fibroids.