Elimination of cervical cancer in Tanzania: Modelled analysis of elimination in the context of endemic HIV infection and active HIV control

Abstract

The World Health Organisation (WHO) has launched a strategic initiative for cervical cancer (CC) elimination which involves scaling up three interventions: human papillomavirus (HPV) vaccination, twice-lifetime HPV-screening screening and pre-cancer/cancer treatment by 2030. CC is challenging to control in countries with endemic human immunodeficiency virus (HIV), as women living with HIV (WLHIV) are at elevated risk of HPV infection, persistence and progression. This analysis estimated the impact of the elimination interventions on CC incidence and mortality but additionally considered more intensive screening for WLHIV, using Tanzania as an example. A dynamic HIV/HPV model was used to simulate the elimination strategy for vaccination, screening and pre-cancer/cancer treatment, with 3-yearly HPV-screening in WLHIV starting at age 25 years, in the context of sustained HIV control in Tanzania from 2020 to 2119. Without vaccination or HPV screening, CC incidence rates per 100 000 women are predicted to fall from 58.0 in 2020 to 41.6 (range: 39.1-44.7) in 2119, due to existing HIV control. HPV vaccination and twice-lifetime HPV-screening for the general population and 3-yearly screening for WLHIV, would reduce CC incidence to 1.3 (range: 1.3-2.5) by 2119, with elimination (<4/100 000) in 2076 (range: 2076-2092). CC mortality rates per 100 000 women are predicted to reach 1.1 (range: 1.1-2.1) with further reductions contingent on increased CC treatment access. Vaccination and 3-yearly HPV-screening for WLHIV is predicted to achieve elimination in the subgroup of WLHIV potentially as early as 2061 (range: 2061-2078), with a 2119 CC incidence rate of 1.7 (range: 1.7-3.3). Scaling-up vaccination and HPV-screening will substantially reduce CC incidence in Tanzania, with elimination predicted within a century. Three-yearly HPV-screening and HPV vaccination, at high coverage rates, would facilitate CC elimination among WLHIV, and thus accelerate elimination in the overall population.

Keywords: cervical cancer; cervical screening; elimination; epidemiology; human immunodeficiency virus; human papillomavirus (HPV) vaccination; mathematical modelling.