The Role of Skin Painting in Predicting Lung Cancer

The mouse skin cancer model provides an important system for studying mechanisms involved in the various stages of carcinogen-esis and for bioassaying tobacco smoke constituents and additives for carcinogenic/cocarcinogenic and tumor-promoting properties as well as for identifying compounds that may inhibit tumor for-mation and malignant conversion. In addition, it is an excellent model for studying the formation of precancerous lesions as well as squamous cell carcinomas. It relates very well to other squa-mous cell carcinoma models and contributes to better understand-ing of the human epithelial cancers including lung cancer. The SENCAR mouse is an established model system demonstrated to be more sensitive than the B6C3F1 or Swiss CD-1 strains in the initiation/promotion skin-painting test method. Although the rela-tionship between mouse skin tumors and any manifestation of the toxicity of tobacco smoke and other complex environmental mix-tures in humans is unknown, the skin-painting model is the only assay that provides a practical method of obtaining a tumorigenic end point with cigarette smoke condensates and other complex mix-tures. This assay provides a rapid response with relative ease of quantification of various parameters of tumorigenic response in-cluding tumor incidence, latency, multiplicity, and malignancy