Trends in breast cancer incidence and mortality.

Breast cancer is the leading form of cancer diagnosed in Canadian women (excluding non-melanoma skin cancer), accounting for about 30% of all new cases. After age 30, incidence rates begin to rise, and the highest rates are among women aged 60 and over. Canadian incidence rates have increased slowly and steadily since 1969, rising most rapidly among women aged 50 and over. Canada's rates are among the highest of any country in the world, ranking second only to those in the United States. After decades of little change, breast cancer mortality rates for all ages combined have declined slightly since 1990. While not dramatic, this decline is statistically significant and is consistent with similar decreases in the United Kingdom, the United States, and Australia. Breast cancer survival rates are relatively more favourable than those of other forms of cancer. Survival rates are better for younger women and for women whose cancer was detected at an early stage. This article presents breast cancer data from the Canadian Cancer Registry, the National Cancer Incidence Reporting System, and vital statistics mortality data, all of which are maintained by the Health Statistics Division of Statistics Canada. These data are provided to Statistics Canada by the provincial and territorial cancer and vital statistics registrars.