Changing burden of cancers related to human papillomavirus in Estonia: a population-based registry study

BACKGROUND AND PURPOSE: Human papillomavirus (HPV) causes multiple cancers. Understanding HPV-related cancer burden may help implement effective strategies for cancer prevention. The aim was to examine incidence and survival trends of eight HPV-related cancer sites in Estonia and estimate the number of cases attributable to HPV. Patient/material and methods: The Estonian Cancer Registry provided data on all cases of eight HPV-related cancer sites diagnosed in Estonia during 1995-2022. Age-standardized incidence trends were analyzed using joinpoint regression, estimating annual percentage change (APC). The number of HPV-attributable cases was estimated using internationally derived site-specific attributable fractions, as tumor HPV status was not available. Five-year relative survival ratios were calculated from national life tables. RESULTS: In all, 11,266 cases of HPV-related cancer sites were diagnosed, of which 6,263 were estimated to be attributable to HPV; over 40% occurred before age 55. In women, estimated average annual number of HPV-attributable cases nearly quadrupled for oropharyngeal cancer (OPC) and tripled for anal cancer. A significant increase in OPC and anal cancer incidence was observed among women (APC 10.0 and 3.8, respectively). Cervical cancer incidence declined after 2012 (APC -5.6). Survival improved for OPC in men (from 13 to 44%) and vaginal cancer in women (from 45 to 73%). INTERPRETATION: HPV-related cancer patterns in Estonia are shifting from cervical to non-cervical cancers. Increasing oropharyngeal and anal cancer incidence highlights the need for prevention strategies beyond cervical screening alone. Strengthening HPV vaccination uptake and sustaining organized cervical screening are critical for reducing future cancer burden.