PROLIFERATION, PLOIDY AND PROGNOSIS IN UTERINE SMOOTH-MUSCLE TUMORS

DNA ploidy, mitotic rate (per 10 high power fields), mitotic index (pe r 1000 tumour nuclei), Ki-67 labelling index and S phase fraction were measured in 23 uterine leiomyosarcomas and 10 tumours of uncertain ma lignant potential. Correlations were calculated by Spearmann rank corr elation, Univariate survival analysis was performed by log rank analys is and multivariate analysis performed by the Cox linear regression me thod, Ki-67 index and S phase fraction were significantly higher in le iomyosarcomas than in tumours of uncertain malignant potential, There was significant correlation between mitotic rate, mitotic index, Ki-67 index and S phase fraction in cases of leiomyosarcoma. Fifteen of 22 leiomyosarcomas and one of 10 tumours of uncertain malignant potential were DNA aneuploid. On univariate analysis of all the smooth muscle t umours, DNA ploidy, presence of significant nuclear atypia and presenc e of coagulative tumour cell necrosis were associated with outcome, On ly DNA ploidy was associated with outcome in the group of leiomyosarco mas. On multivariate analysis of all of the smooth muscle tumours, DNA ploidy, age and grade of atypia were independently associated with ou tcome. No single factor was independently predicitive of outcome in th e group of leiomyosarcomas. Alternative indices of cell proliferation correlate with mitotic rate in uterine leiomyosarcoma and do not provi de additional useful prognostic information, DNA ploidy, age and grade of atypia are independently associated with outcome in uterine smooth muscle tumours and measurement of DNA ploidy may be useful in identif ication of cases with an adverse prognosis.