The epidemiology of malignant neoplasms of the large intestine in Canada: 1941-1985.

Morbidity and mortality from malignancies of the large intestine, in Canada, were examined for the periods 1970-1980 and 1941-1985, respectively. Age-standardized morbidity rates for males have increased significantly during the period studied (18.4 to 26.2 new cases per 100,000 population per year; p less than 0.0001), with increases in morbidity being most attributable to significant increases in age-specific rates for males aged 45-54, 55-64, 65-74, and 75-84 years (p less than or equal to 0.015). Standardized rates for females have also increased significantly (21.2 to 23.3 new cases per 100,000 population per year; p = 0.012) as was the case for age-specific rates in women aged 65-74, 75-84, and 85+ years, which have risen sharply (p less than 0.015), whereas rates in women aged 25-34 and 35-44 years have declined significantly (p less than 0.04). Significant reductions in female age-standardized mortality rates (17.0 to 10.2 deaths per 100,000 population per year; p less than 0.0001) are attributable to significant declines in mortality for all of the eight age groups studied (p less than 0.013). The significant reduction in male age-standardized mortality rates (14.2 to 13.3 deaths per 100,000 population per year; p = 0.04) is attributable to significant reductions in mortality for five of the eight age groups studied (0-24, 25-34, 35-44, and 45-54 years)--rates for males aged 85+, however, have increased significantly (p less than 0.0001).