UTERINE LEIOMYOSARCOMA HAS DEREGULATED CELL-PROLIFERATION, BUT NOT INCREASED MICROVESSEL DENSITY COMPARED WITH UTERINE LEIOMYOMA

Objective. To investigate the differences of biological aggressiveness in terms of proliferating cell nuclear antigen (PCNA) expression, cel l proliferation, and microvessel density between uterine leiomyosarcom a and leiomyoma. Study design. All patients with uterine leiomyosarcom a undergoing surgery at National Cheng Kung University Hospital were e ligible. Forty-four patients with uterine myoma were also studied as t he benign counterpart. The paraffin-embedded slides were stained with hematoxylin and eosin to confirm the presence of tumor and to quantita te mitoses, PC 10 far measurement of PCNA expression, MIB 1 for measur ement of cell proliferation, and factor wr for quantitation of microve ssel density. The immunohistochemical findings of the slides were corr elated with clinocopathologic findings of the patients, and the data w ere analyzed by either chi(2) or unpaired t test. Results. Six patient s with uterine leiomyosarcoma and 44 patients with uterine leiomyama w ere studied. Statistically significant higher mean levels of PCNA and MIB 1 were observed in uterine leiomyosarcoma compared with those of u terine myoma (for PCNA expression, P = 0.0001; for MIB 1, 11.61 +/- 11 .42% vs 0.45 +/- 0.21%, P < 0.0001). No significant difference of micr ovessel density was observed between these two groups (65.73 +/- 48.62 vs 41.97 +/- 28.20, P = 0.084). Among the six patients with leiomyosa rcoma, two patients with a higher percentage of MIB 1-positive tumor c ells died of recurrent disease. In contrast, two patients with lower M IB 1 counts were disease-free for 3 years or more. Conclusion. Deregul ated cell growth in uterine leiomyosarcoma account for the biological aggressiveness of this tumor. Furthermore, the percentage of MIB 1-pos itive tumor cells seems to be associated with the prognosis or extent of uterine leiomyosarcoma. (C) 1997 Academic Press.