p53, proliferating cell nuclear antigen, and Ki-67 expression in extrauterine leiomyosarcomas

Extrauterine leiomyosarcomas, because of their relative rarity, are poorly understood in regards to their malignant potential and biologic markers. Many human tumors are characterized by overexpression of p53, a tumor suppressor protein, and by expression of nuclear proteins associated with proliferation, such as proliferating cell nuclear antigen (PCNA) and Ki-67. We examined expression of these markers in 44 extrauterine leiomyosarcomas from 10 men and 25 women who ranged in age from 25 to 82 years (mean, 56 yr). Clinical follow-up was obtained in 34 (97%) of 35 patients, p53 expression was studied with two monoclonal antibodies (1801, D07) by use of an antigen retrieval method. p53 overexpression was present in 19 (43%) of 44 cases, whereas Ki-67 and PCNA staining were seen in 29 (66%) and 36 (82%) of 44 cases, respectively. There was no correlation between overall survival or recurrence and p53 or PCNA and Ki-67 expression. We conclude that p53, Ki-67, and PCNA are expressed in a large number of extrauterine leiomyosarcomas. In this study, the expression of these markers did not predict biologic behavior.