Invasive Cervical Cancer Incidence and Mortality Among Canadian Women Aged 15 to 29 and the Impact of Screening

Objective: The utility of screening young women for cervical cancer is questionable given the likelihood of pre-cancer regression and the potential harm of the intervention. Our objective was to determine the incidence and mortality rates of invasive cervical cancer (ICC) in women aged 15 to 29 years and to assess changes in rates since the uptake of screening.

Methods: The incidence of ICC cases from 1970 to 2007 was obtained from records in the Canadian Cancer Registry and from the National Cancer Incidence Reporting System. Mortality rates in women with ICC for the same time period were obtained from the Canadian Vital Statistics Death Database. Data were classified by age group and year at diagnosis or death, assessed at five-year intervals. The incidence was further analyzed according to histology.

Results: ICC among 15- to 19-year-olds is rare and has remained relatively constant from 1970-1974 to 2005-2007. From 1975-1979 to 2005-2007, the incidence in 20- to 24-year-olds declined from 3.2 to 1.2 per 100 000. From 1980-1984 to 2005-2007, the incidence in 25- to 29-year-olds declined from 11.1 to 6.3 per 100 000. Deaths among 15- to 19-year-olds and 20- to 24-year-olds are rare, but in 25- to 29-year-olds mortality declined from 0.9 to 0.5 per 100 000 between 1975-1979 and 2005-2007. Among 20- to 24-year-olds, rates of all cervical cancers and squamous cell carcinomas declined, while adenocarcinomas and unknown types were rare. In 25- to 29-year-olds there was a decline in all cervical cancers and squamous cell cancers and an apparent increase in adenocarcinoma.

Conclusions: ICC in adolescents is rare and does not justify population-based screening. Screening appears to have affected the incidence of ICC in 20- to 24-year olds and incidence and mortality from ICC in 25- to 29-year-olds.