Leading cancers--changes in five-year relative survival.

OBJECTIVES Changes in five-year relative survival ratios for prostate, breast, colorectal and lung cancer cases are examined. Ratios for cases diagnosed in the 1985-1987 period are compared with those for 1992-1994. Incidence and mortality rates between 1985 and 1999 are compared with changes in relative survival. DATA SOURCES Data are from the Canadian Cancer Registry, the National Cancer Incidence Reporting System, the Canadian Mortality Data Base, and life tables. ANALYTICAL TECHNIQUES Analysis was conducted using the maximum likelihood method of Esteve. Age-standardized ratios for a given cancer were calculated by weighting age-specific ratios to the age distribution of patients diagnosed with that cancer. Statistical tests were used to compare corresponding age-specific and age-standardized ratios across the two periods. National estimates exclude Québec and New Brunswick. MAIN RESULTS Between the 1985-1987 period and the 1992-1994 period, increases in five-year age-standardized relative survival ratios were dramatic for prostate cancer, large for breast cancer, and somewhat smaller for colorectal cancer. There was little absolute change in the ratios for lung cancer.