Cancer epidemiology is the study of the distribution and determinants of the likelihood of cancer development. Cancer epidemiology can be used to identify events that increase or decrease cancer occurrence in specific people cancer epidemiology uses epidemiological methods to find the cause of cancer and to identify and develop improved treatments. Normally Squamous cell carcinoma of the lung is a central rather than a peripheral form of lung cancer. Rates of squamous cell carcinoma in the lung periphery are typically sited in the 15-30% range. Given the differences in cell biology and carcinogenesis of central versus peripheral SCC, a potential epidemiologic shift might suggest a change in tumor biology.