Sheldon Singh, BSc
Colorectal cancer is the second leading cause of cancer death in North America and Western Europe. This disease tends to occur mainly in older individuals. Early-stage disease is curable in more than 80% of patients. Unfortunately, more than 55% of patients present late with evidence of lymphatic or distant metastases. There is now compelling evidence that screening of average risk individuals over 50 can identify disease at a more curable stage thereby allowing for more effective management and subsequent reduction in mortality.
Epidemiology
Cancer of the colon and rectum kills more Canadians than any other cancer with the exception of lung cancer. During their lifetime, women have a 1 in 18 chance of developing colorectal cancer while men a 1 in 16 chance. This year, the disease is expected to affect 16,600 Canadians (with roughly 93% occurring in people over age 50) and claim 6,300 lives (with roughly 95% occurring after age 50). Rates of colorectal cancer in Canada have been declining, particularly among women. This may be due to changes in diet as well as the casual use of screening techniques.
Risk Factors
Age is a major risk factor for developing colorectal cancer. Approximately 75% of colorectal cancers are sporadic and without any identifiable risk factors other than age. Colorectal cancers are rare before 50 and over 90% are diagnosed after 60.
