Colorectal cancer is the fourth most common cancer and the second leading cause of cancer death in the United States. Survival is strongly determined by stage at the time of diagnosis but only approximately 40% of all new cases are diagnosed at local stage. Effective screening methods are available which can lead to early detection and reduced mortality from this disease, but these remain underutilized. We believe the factors that influence colorectal cancer screening rates in a population determine the stage at diagnosis of colorectal cancer in that population. We propose to conduct a population based case: control study to identify factors associated with stage at diagnosis of colorectal cancer in a high-risk, underserved population. In particular, we will study the relationship between physician characteristics, type of practice, specialty training, knowledge of screening guidelines, attitudes regarding screening, actual screening practices, approaches to patient education and communication, and perceived barriers to screening in relation to stage at colorectal cancer diagnosis. The study will compare approximately 533 patients with incident local stage invasive colorectal cancer (cases) and 1242 patients with more advanced stage disease (controls) identified from a population-based cancer registry. Logistic regression will be used to assess the relationship between cancer stage and physician characteristics and behaviors while controlling for confounding. This research will increase the knowledge base regarding screening practices of community-based physicians and how these practices affect stage at diagnosis and ultimately colorectal cancer outcome. A better understanding of the utilization of currently available screening procedures and attitudes toward screening will help illuminate the reasons for the low prevalence of colorectal screening and high colorectal mortality observed in the United States. Public Health Relevance: Underutilization of colorectal cancer screening contributes to delays in detection causing patients to be diagnosed with larger (more advanced stage) tumors. We will conduct a study examining the relation between physician factors (training, beliefs about screening, screening practices) and stage at diagnosis of colorectal cancer. These characteristics can be used to identify practitioners likely to benefit from educational efforts designed to increase colorectal cancer screening. ? ?