Characterization of a murine lung adenocarcinoma (LAC1), a useful experimental model to study progression of lung cancer.

Lung cancer is one of the most important avoidable causes of death around the world, the most widespread carcinoma, with a very poor prognosis, and is the leading cause of cancer death in both developed and developing countries. We report morphological and biological behavior characteristics of a tumor that arose in only one BALB/c mouse of an experimental group treated with urethane, a chemical lung-tumorigenic agent. Morphological and immunochemical analysis indicated phenotypic compatibility with a lung adenocarcinoma. The tumor was named LAC1 (lung adenocarcinoma 1). Implant success in eight LAC1-bearing mice generations was 100%, with a fast evolution (58 survival days) and good metastatic capacity (41% of animals with metastases). The tumor induced a paraneoplastic syndrome characterized by anemia, neutrophilia, cachexia, splenomegaly and thymic atrophy. The lymphoproliferation to Con A was altered in tumor-bearing mice. This lung adenocarcinoma may be a useful experimental model for studying tumor progression, paraneoplastic syndromes and immunology in carcinogenic studies.