Proliferative activity, p53 accumulation and neoangiogenesis in pulmonary carcinosarcomas and pulmonary blastomas

Carcinosarcoma and pulmonary blastomas are rare biphasic tumors. Lung cancer pathogenesis is a multistep process. Proliferative activity, p53 accumulation and angiogenesis are of well-known relevance and ought to be evaluated in the epithelial and mesenchymal components of these tumors. Using antibodies against Ki-67 epitope MIB1 and proliferating cell nuclear antigen (PC 10) in 10 carcinosarcomas, tumors revealed a significantly higher proliferative activity in the epithelial component compared with the mesenchymal component in the MIB1 reaction (p = 0.013). In three pulmonary blastomas of the biphasic subtype, proliferative activity was similar in both parts. In five of 10 carcinosarcomas and in one of three pulmonary blastomas, accumulation of the p53 epitopes Pab 1801 and/or DO-1 was found. At the tumor front, a significantly higher vessel density was found compared with the central parts (p < or = 0.015) using a monoclonal antibody against human endothelium (CD 31). No differences were found between carcinosarcomas and pulmoblastomas. Higher proliferative activity in carcinosarcomas revealed a better prognosis regarding metastasis behavior (p = 0.05) and tumor-associated death in the follow-up (p < or = 0.017). p53 accumulation and microvessel density were of no prognostic value. This is in contrast to results in non-small cell lung cancer, pointing to a different biologic behavior.