Colorectal cancer: epidemiology, risk factors, and health services.

Colorectal carcinoma is the third most common cancer in the United States in both men and women but still remains the second leading cause of cancer-related deaths. The risk of developing colorectal cancer increases with age. Additional risk factors include family history of colorectal cancer, heredity conditions such as polyposis and hereditary nonpolyposis colorectal cancer, and personal history of inflammatory bowel disease, polyps, and cancers. Health services is a new scientific discipline that examines the quality of care, often at the population level, and may examine parts or the entire spectrum of care.