DISEASE CHARACTERISTICS: Histologically documented metastatic breast or endometrial carcinoma or mesothelioma not amenable to surgical and/or radiotherapeutic cure or long-term control Measurable soft tissue, bony, or visceral lesions required Indicator lesions other than blastic bony metastases and pleural effusions required for breast cancer Hormone receptor status (breast cancer): Estrogen-receptor-positive and/or progesterone-receptor-positive