Cervical cancer, caused by a persistent infection with high-risk human papillomaviruses (HR-HPV), remains one of the most common cancers among women worldwide. Although screening programs in high-income countries have successfully reduced cancer rates, these rates have stagnated or even increased in some regions. Research on HPV has predominantly focused on younger women, as screening programs in high-income countries typically include women under 65 years of age, and in low-income countries, women under 50 years of age. However, cervical cancer incidence is particularly high among women over 50 in many regions worldwide. The risks of the disease in this age group are often underestimated, despite their higher mortality rate. In older women, an increased risk could arise from new persistent HPV infections, but reactivation of older HPV infections may also occur.
Under the leadership of Prof. Dr. Stefanie J. Klug, head of the Chair of Epidemiology, the research team, including doctoral researcher Vanesa Osmani, investigated the global prevalence of HPV in women aged 50 and older with normal cytology. The findings were published in the international journal The Lancet Microbe under the title “Global prevalence of cervical human papillomavirus in women aged 50 years and older with normal cytology: a systematic review and meta-analysis.” The journal boasts an impact factor of 20.9.
“Our goal was to provide a comprehensive and up-to-date overview of HPV prevalence in older women and to highlight its implications for prevention and screening strategies,” summarizes Professor Klug. “We examined HPV prevalence in unvaccinated women aged 50 years and older worldwide, while also conducting regional analyses. Our study addresses a significant gap in the data on global HPV prevalence in older women.”
The study systematically reviewed published research and analyzed quantitative studies with data on women aged 50 years and older with normal cytology. HPV prevalence was estimated using random-effects models, while geographic differences were explored through subgroup analyses and meta-regressions. Of 9,099 articles identified, 132 were included in the qualitative synthesis, including 73 studies testing both high-risk and low-risk HPV (any-HPV) and 102 studies focusing exclusively on high-risk HPV (HR-HPV). “We included studies from 59 countries worldwide. However, Africa and Oceania were underrepresented, as no studies focused on older women from southern Africa were found. Additionally, there was only one study from the Balkans and none from New Zealand or Canada,” explains Vanesa Osmani.
The global prevalence of any-HPV among women aged 50 years and older with normal cytology was 11.7%, while HR-HPV prevalence was 6.5%. Significant geographic differences were observed: the highest prevalence rates were found in West Africa and Central America, while the lowest were in Western Europe and West Asia. Age-related patterns showed that global prevalence of any-HPV tended to decrease with advancing age, though uncertainty increased among women over 70 years. HR-HPV prevalence showed little variation across age groups.
“A key finding is the substantial regional variation, with the highest prevalence in West Africa and the lowest in Western Europe,” Osmani notes. “HPV-16 had the highest prevalence globally and is likely to decrease in the long term due to the immunity provided by available HPV vaccines. However, HPV-53, a type not covered by vaccines and potentially carcinogenic, also showed a high prevalence. Infections with HPV-18 and HPV-31 were less common compared to studies focusing primarily on younger women.”
The study underscores the need to reconsider screening strategies, particularly in regions with high HPV and cervical cancer incidence, such as Africa and Central America. Additionally, the findings support evaluating the cost-effectiveness of screening programs for older women. Further research is needed to better understand the dynamics of HPV infections in older women, especially regarding the mechanisms of persistence, reactivation, and new infections. Regional prevalence data are particularly important for developing tailored screening programs. Professor Klug emphasizes, “Future research must address regional gaps and study representative samples of older women in high-quality studies.”
Link to the Chair of Epidemiology website
Contact:
Prof. Dr. Stefanie J. Klug, MPH
Ordinaria
Chair of Epidemiology
Georg-Brauchle-Ring 56
D-80992 München
Tel.: 089 289 24951
E-Mail: stefanie.klug(at)tum.de
Vanesa Osmani
Chair of Epidemiology
Georg-Brauchle-Ring 56
D-80992 München
E-Mail: vanesa.osmani(at)tum.de
Text: Jasmin Schol
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