Trends in the incidence of human papillomavirus-related noncervical and cervical cancers in Alberta, Canada: a population-based study.

INTRODUCTION

Recent epidemiologic studies have suggested that the incidence of noncervical cancers associated with human papillomavirus (HPV) is increasing. We assessed temporal, age-specific and sex-specific changes in the incidence of HPV-associated cancers in a population-based study.

METHODS

We used the Alberta Cancer Registry, a registry of all cancers diagnosed in the province of Alberta, Canada, to identify patients with cancers of the oropharynx, cervix, vulva, vagina, anus and penis (cancers associated with HPV) between Jan. 1, 1975, and Dec. 31, 2009. We estimated the age-standardized incidence of each cancer by sex- and age-specific group and assessed the annual percentage change using joinpoint regression.

RESULTS

The age-standardized incidence of oropharyngeal cancers increased for each 5-year interval of the study period among men (annual percentage change 3.4, p < 0.001) and women (annual percentage change 1.5, p = 0.009). For anal cancers, the age-standardized rates increased among women (annual percentage change 2.2, p < 0.001) and men (annual percentage change 1.8, p = 0.008). The age-standardized incidence of cervical cancer increased with age, reaching an annual percentage change of -3.5 among women aged 75-84 years (p = 0.04). The rates of other HPV-associated cancers (vulvar, vaginal and penile) showed little change.

INTERPRETATION

Our findings showed increases in the incidence of the HPV-associated cancers of the oropharynx and anus among men and women, and increases in cervical cancer among younger women. The incidence of HPV-related cancers in younger age groups should continue to be monitored. Programs to prevent HPV infection, such as vaccination, should be considered for males as well as females.