Cervical cancer incidence trends in Canada: a 30-year population-based analysis.

Objectives: To use the most recent data to update the trend in cervical cancer incidence in Canada over the 30 year period from 1978 to 2009.

Methods: Registered cases of cervical cancer and the corresponding person years for the Canadian population were retrieved from an online data repository of the International Agency on Research on Cancer and from Statistics Canada for the period 1978 to 2009. Annual age-standardized rates were estimated for all data combined and for each province separately. The ages of cases were aggregated into three groups: 25 to 39, 40 to 59, and 60 to 75 years. Joinpoint regression analysis was used to describe the trend across age groups and provinces.

Results: Between 1978 and 2006, the age-adjusted cervical cancer rate in Canada decreased from 20.05 to 12.66 per 100 000 females; after 2006 the rate increased. Greater reductions were observed in the older age groups. The average annual percentage change (AAPC) was -1.1% (95% CI -1.1% to 0.09%), -1.8% (95% CI -2.5% to -1.2%), and -2.6% (95% CI -3.9% to -1.4%) for age groups 25 to 39, 40 to 60, and 60 to 75, respectively. The AAPC varied between provinces, ranging from -0.22% (95% CI -1.4% to 0.9%) in Saskatchewan to -3.02% (95% CI -4.5% to -1.5%) in Newfoundland and Labrador. In Ontario the incidence of cervical cancer increased annually between 2006 and 2009. The trend in British Columbia included a significant change of slope in 1984.

Conclusion: The incidence of cervical cancer decreased in Canada and across all provinces between 1978 and 2009. The decrease was greater in older women.