Women living with HIV have a six-fold higher risk of developing cervical cancer compared with women without HIV infection. In view of this increased risk, it was estimated that nearly 5% of all cervical cancer cases worldwide are attributable to HIV infection. This attributable fraction varies greatly by region and is highest in countries where coverage of human papillomavirus (HPV) vaccination, and of cervical cancer screening and treatment for all women and girls, is suboptimal.
Dr Shona Dalal of the World Health Organization (WHO) and colleagues performed a systematic literature search and meta-analysis of five databases to identify studies analysing the association between HIV infection and cervical cancer. They published their findings on 16 November 2020 in The Lancet Global Health.
Geographical disparities in the cervical cancer burden reflect the availability, coverage, and quality of preventive strategies and the prevalence of risk factors. Nearly nine in ten women who die from cervical cancer live in low-income and middle-income countries. Besides infection with high-risk HPV, other known risk factors include smoking, increased parity, and infection with HIV; HIV enhances HPV-induced carcinogenesis.
Cervical cancer is the most frequently detected cancer in women living with HIV and is classified as an AIDS-defining illness. Although high-burden settings for cervical cancer and HIV overlap, the extent of the contribution of HIV to the burden of cervical cancer and the proportion of cervical cancer cases due to co-infection with HIV have yet to be quantified, the authors wrote in the study background.
In this meta-analysis and modelling study, the investigators aimed to provide a pooled estimate of the relative risk for cervical cancer among women living with HIV in Africa, Asia, Europe, and North America and present the estimated number of cases of cervical cancer among women living with HIV and attributable to HIV, based on UNAIDS HIV prevalence and GLOBOCAN 2018 cancer estimates for 2018.
In 24 studies that have met inclusion criteria, there were 236 127 included women with HIV. The pooled risk of cervical cancer was increased in women living with HIV (risk ratio [RR] 6.07, 95% confidence interval [CI] 4.40–8.37). Globally, 5.8% (95% CI 4.6–7.3) of new cervical cancer cases in 2018 (33 000 new cases, 95% CI 26 000–42 000) were diagnosed in women living with HIV and 4.9% (95% CI 3.6–6.4) were attributable to HIV infection (28 000 new cases, 20 000–36 000).
The most affected regions were southern Africa and eastern Africa. In southern Africa, 63.8% (95% CI 58.9–68.1) of women with cervical cancer (9200 new cases, 95% CI 8500–9800) were living with HIV, as were 27.4% (23.7–31.7) of women in eastern Africa (14 000 new cases, 12 000–17 000).
Age-standardised incidence rates of HIV-attributable cervical cancer were more than 20 per 100 000 in six countries, all in southern Africa and eastern Africa.
The authors concluded that it is important to improve access to cervical cancer prevention for all women in all settings, but particularly in countries where access to health services is difficult and HIV prevalence is high. Focusing on both cervical cancer prevention and HIV prevention, including integration of cervical cancer screening and treatment with HIV services, can optimise benefits. Such an approach in countries with the highest burden of HIV-attributable cervical cancer will contribute substantially to delivering on the WHO 2030 targets of 90% coverage of vaccination of girls, 70% coverage of screening, and 90% coverage of treatment leading to elimination of cervical cancer as a major public health problem.
The study was funded by the WHO, US Agency for International Development, and US President’s Emergency Plan for AIDS Relief.
Stelzle D, Tanaka LF, Ken Lee K, et al. Estimates of the global burden of cervical cancer associated with HIV. Lancet Glob Health; Published Online 16 November 2020. DOI: https://doi.org/10.1016/ S2214-109X(20)30459-9.