Progress in cancer control leads to a substantial number of cancer deaths avoided in Canada

Abstract

It is currently not known how many more cancer deaths would have occurred among Canadians if cancer mortality rates were unchanged following various modern human interventions. The objective of this study was to estimate the number of cancer deaths that have been avoided in Canada since the age-standardized overall cancer mortality rate peaked in 1988. We applied the age-specific overall cancer mortality rates from 1988 to the Canadian population for all subsequent years to estimate the number of expected deaths. Avoided cancer deaths were estimated as the difference between the observed and expected number of cancer deaths for each year. Since 1988, there have been 372 584 (standardized mortality ratio = 0.77) and 120 045 (standardized mortality ratio = 0.90) avoided cancer deaths in males and females, respectively (492 629 total). Nearly half a million cancer deaths have been avoided in Canada since the overall cancer mortality rate peaked, which demonstrates the exceptional progress made in modern cancer control in Canada.

Figure 1.

Age-standardized cancer mortality rates and the number of cancer deaths avoided between 1950 and 2022. A) Age-standardized overall cancer mortality rates from 1950 to 2022, by sex, based on the 2011 Canadian standard population. The vertical dashed line indicates 1988, the peak year for age-standardized overall cancer mortality. B) The observed and expected number of overall cancer deaths in the period since overall age-standardized mortality rates peaked in 1988, separately by sex. The shaded gray areas represent the number of cancer deaths avoided since overall cancer mortality rates peaked.