ABSTRACT
Cigarette smoking has made lung cancer an epidemic problem which claims over one fourth of all cancer-related deaths in society. Synergistic relationships among carcinogens result in either the requirement of lower doses of carcinogen or in faster progression to cancer compared with the effects of each carcinogen clone. The carcinogenic activity of synergistic carcinogens together is greater than the summation of the effects of the individual carcinogens. Carcinogenesis in autogenous heterotopic bronchial epithelium provides cost-effective models. Small animal models are far less expensive than large animal models. Various types of small animals have been used, including rats, mice, and hamsters. The techniques and routes which have been used to administer carcinogens include systemic administration, endobronchial inhalation, endobronchial instillation, focal orthotopic endobronchial methods, peripheral parenchymal implantation, and focal heterotopic endobronchial methods. Although the systemic administration of certain carcinogens is an effective means for producing cancer, few carcinogens act specifically on lung tissue.
