Carboplatin delays mammary cancer 4T1 growth in mice.

Carboplatin is commonly used to treat a variety of tumors. We investigated the effects of carboplatin (100mg/kg) in the development and metastatic dissemination of the 4T1 mice mammary carcinoma. Carboplatin was able to reduce tumor volume and the number of lung metastases in 50% compared to the control animals. Mitotic and apoptotic indices were also decreased by the treatment. Assessment of the vascularization of the tumors revealed a significant decrease in blood vessel formation by carboplatin. A decrease in nuclear positivity of CDC47 and cyclin D1 was observed in the group treated with carboplatin when compared to the control group. Positivity for p53 was observed in the control group (2/28; 5%) and the treated group (5/71; 4%). Carboplatin has been demonstrated to be an efficient regulator of 4T1MMT growth and dissemination. The action of this chemotherapeutic agent seems to be related to the induction of apoptosis and inhibition of angiogenesis and cell proliferation.