According to World Health Organization (WHO) statistics, cervical cancer is the fourth most common cancer affecting women. In 2018, an estimated 570,000 women worldwide were diagnosed with cervical cancer and about 311,000 women died of the disease. On the other hand, cervical cancer is a cancer that is easy to prevent with the help of appropriate preventive measures. Cervical cancer is caused by the human papillomavirus (HPV). Vaccination against HPV has been available since 2016, and in Germany there is also a vaccination recommendation for all girls and boys between the ages of 9 and 14. Preliminary stages of cervical cancer can be detected early in the course of screening and, if necessary, effectively treated. Furthermore, cervical cancer is the most commonly detected cancer in women living with the human immunodeficiency virus (HIV) because their immune system is weakened by HIV infection.
The Chair of Epidemiology headed by Prof. Dr. Stefanie Klug, in cooperation with the Center for Global Health under the direction of Prof. Dr. Dr. Andrea S. Winkler, has now devoted itself to this relevant topic in the publication “Estimates of the Global Burden of Cervical Cancer Associated with HIV”. Other cooperation partners included the WHO and its departments for sexual and reproductive health and research and for global HIV, hepatitis and STI (Sexually Transmitted Infection) programmes, as well as the International Agency for Research on Cancer (IARC). The article was published in the renowned journal “The Lancet Global Health”, which has an impact factor of 21.597.
“Based on our strong contacts with IARC and WHO as well as the Joint United Nations Programme on HIV/AIDS (UNAIDS), this work certainly suits our research focus very well", said Prof. Klug. “ Therefore, naturally, we are delighted about this wonderful cooperation between the institutions involved.”
The lead authors, Dr. Dominik Stelzle, Research Associate at the Center for Global Health and the Chair of Epidemiology, and Dr. Luana Tanaka, Research Associate at the Chair of Epidemiology, conducted a systematic review and meta-analysis of a total of 24 studies from 1981 to 2016 that involved 236,127 female participants with HIV from four continents (Africa, North America, Asia, and Europe). A total of 2,138 cervical cancer cases were included. Furthermore, these results were combined and evaluated with data from UNAIDS on global HIV infections and cervical cancer data from IARC, the WHO's cancer research centre.
“Up until now, there have only ever been estimates from countries with a high net income”, says Dr. Stelzle, describing the prerequisites. “This was also the reason why we have now looked at the figures regarding the global burden of cervical carcinoma in connection with HIV infections. In most parts of the world these figures are below five percent. However, in some countries, it is estimated that in well over 40 percent of cases, HIV infection is a co-factor."
“Indeed, many countries with low average net incomes have high rates of cervical cancer associated with HIV infection", adds Dr. Tanaka.
The aim of the study was to calculate the proportion of women living with HIV among women with cervical cancer. The authors found that 5.8 percent of all new cervical cancer cases worldwide in 2018 were diagnosed in females with an HIV infection. This corresponds to 33,000 cases per year, of which 85 percent occur in sub-Saharan Africa.
Furthermore, based on the results it could also be demonstrated that women with an HIV infection have a six times higher risk of getting cervical cancer than women without an HIV infection.
“The relationship between cervical carcinoma and HIV is obvious”, explains Prof. Winkler. "Cervical carcinomas are usually caused by infections involving human papilloma viruses, which are sexually transmitted in the same way as HIV. Based on our results, one could assume that infection with HIV is a risk factor for infection with HPV."
The most affected regions are South and East Africa, where 63.8 percent (South Africa) and 27.4 percent (East Africa) of cervical cancers were diagnosed in women with HIV infection. “With over 75 percent, Eswatini in Southern Africa is the country with the highest proportion of women suffering from cervical cancer linked to HIV, followed by Lesotho with 69 percent, Botswana with 67 percent, South Africa with 64 percent and Zimbabwe with 52 percent", said Dr. Tanaka.
Based on the results of the review and the meta-analysis, the authors found that women with HIV infection have a significantly higher risk of developing cervical cancer. HPV vaccinations and early cervical cancer screening are therefore especially important for sub-Saharan Africa. “We also recommend that women who have tested positive for HIV should also be tested for cervical cancer from now on", explains Dr. Stelzle.
The WHO has set itself the following targets to be achieved by 2030 on the basis of a global strategy:
- 90 percent of girls worldwide under the age of 15 are to be vaccinated against HPV.
- Cervical carcinoma screening is to be carried out in 70 percent of women and girls up to the age of 35 and for a second time up to the age of 45.
- 90 percent of women and girls who have been diagnosed with cervical cancer and its preliminary stages are to receive treatment.
“We naturally hope that the WHO's global strategy will also change the situation on the ground in affected countries", said Prof. Klug. “In Africa, cervical cancer screening is already available, but so far mainly for women who have a higher socio-economic status and are therefore able to afford it. The goal must be to break this dependence on economic possibilities and to achieve a situation where HPV vaccinations for girls and screenings for women become free of charge."
Based on the global strategy, the WHO launched a wide-ranging campaign on 17 November 2020 with the aim of combating cervical carcinoma until it is the world's first type of cancer to be eliminated. Buildings around the world were illuminated in the colour “Teal” (petroleum) to draw attention to the issue, including the façade of the lecture hall building at the TUM University Hospital rechts der Isar.
Prof. Dr. Stefanie Klug
Chair of Epidemiology
phone: 089 289 24950
Prof. Dr. Dr. Andrea Winkler
Center for Global Health
Department for Neurology
TUM University Hospital rechts der Isar
Ismaninger Straße 22
Dr. Dominik Stelzle
Chair of Epidemiology/Center for Global Health
Dr. Luana Tanka
Chair of Epidemiology
phone: 089 289 24960
Text: Romy Schwaiger
Photos: Andreas Heddergott (TUM)/Chair of Epidemiology/Center for Global Health