Breast cancer trends in Manitoba: 40 years of follow-up.

This study reports a comprehensive array of breast cancer statistics for Manitoba for a 40-year period. Data from the Manitoba Cancer Registry were combined with the provincial population-based registration file to determine trends in breast cancer incidence, prevalence and mortality rates, as well as survival and the probability of being diagnosed with breast cancer in the next 10 years. The age-standardized incidence rate of breast cancer increased by 0.99/100,000 women per year over the 40 years of follow-up (69.6/100,000 women in 1960, 109.9/100,000 women in 1999). Mortality rates peaked in 1986 (35.7/100,000 women), while the 1999 mortality rate (26.0/100,000 women) was almost comparable to the 1960 rate (22.4/100,000 women). No significant trend in mortality rate was observed over the 40-year period. The 5-year prevalence rate of breast cancer increased by 8.6/100,000 women per year. Between 1960-64 and 1995-99, 5-year survival increased from 0.62 to 0.86. The probability of being diagnosed with breast cancer in the next 10 years increased the most for women 60 years of age. The breast cancer burden in Manitoba is rapidly evolving mainly because of the increasing incidence and the better survival of cases. Key words: breast neoplasms, incidence, prevalence, registries, vital statistics.