Initiators and promoters of lung cancer.

As we expand our knowledge of the initiators and promoters of lung cancer, early detection and intervention strategies show great potential in individuals at high risk, especially smokers and exsmokers. Documented mutations of dominant oncogenes and tumor suppressor genes in human lung cancer cells may represent important steps in the pathogenesis of invasive cancer. The precise molecular events and their sequence that lead to tumor promotion in lung cancer, however, are less well understood. Chemointervention with agents like the retinoids may halt proliferation of cancer cells prior to the development of metastatic competence. Use of anti-growth-factor therapy and peptide hormone antagonists may also have a role in intervention approaches. This paper reviews present understanding of the initiation and promotion of lung cancer, as well as preventive strategies currently proposed for patients at risk.