To examine incidence trends in squamous cell cancers of the cervix, vulva, vagina, anus, penis and oropharynx, and cervical adenocarcinoma for the period 1953-2015, and to determine how many currently incident cases may be prevented by bi/quadri- and nona-valent HPV vaccination
We extract data from the Cancer Registry of Norway, which has complete and accurate registration of all cancer cases in Norway for the whole study period. Trends in incidence are examined by joinpoint regression and the annual percentage change statistic for each cancer site and for each sex. To estimate the preventive potential of HPV vaccination, we use previously published accounts of fractions attributable to HPV for each cancer site
Over the period 1953-2015, we observe significantly increasing incidences of anal, oropharyngeal, penile and vulvar cancer, and of cervical adenocarcinoma. The increase was most pronounced, with annual percentage changes exceeding 2, for anal cancer (for each sex) and for oropharyngeal cancer among men. Cervical squamous cell cancer incidence decreased after the introduction of screening, but remained stable after 2004. The incidence trends highlight the importance of primary prevention of HPV-related cancers. We show that the number of cases that can be prevented by HPV vaccination in Norway is substantial, also for non-cervical HPV-related cancers, and among men. Moreover, in comparison with the bi/quadrivalent HPV vaccines, use of the nona-valent vaccine will prevent a substantial additional number of cervical cancer cases in Norway