Cervical cancer burden remains high in many low- and middle-income countries, but cases have declined in several regions of the world, including India, according to an observational study published in The Lancet Global Health journal. In 2020, over 600,000 new cases of cervical cancer, and 3,40,000 deaths from the disease were reported.
Cervical cancer cases have declined in several regions of the world in the past three decades, including Asia, Latin America, North America and western Europe. Cervical cancer is a largely preventable disease due to the development of effective human papillomavirus (HPV) vaccines and screening programmes.
Countries with major declines in cervical cancer cases
The study authors analysed trend data from 1988 to 2017, and observed major declines in cervical cancer cases in Asian countries including India, Thailand and South Korea, in some Latin American countries including Brazil, Colombia and Costa Rica, and in Eastern European countries including Poland, Slovenia and Czechia.
Countries with increases in cervical cancer cases
The authors, however, observed increases in cervical cancer cases in the past decade in Eastern European countries such as Latvia, Lithuania and Bulgaria, in Eastern Africa, and in The Netherlands and Italy.
Increased prevalence of human papillomavirus among younger generations of women, and a lack of effective screening programmes are some of the reasons behind recent increases in cervical cancer cases.
What are WHO’s targets to eliminate cervical cancer?
With an aim to reduce the incidence of cervical cancer below a threshold of four cases per 100,000 women per year in every country by 2030, the World Health Organization (WHO), in 2020, announced a target to accelerate the elimination of the disease as a public health problem. The new study identifies the countries and regions where efforts need to be scaled up to reach WHO targets.
In a statement released by The Lancet, Dr Deependra Singh from the International Agency for Research on Cancer (IARC), France, said HPV vaccination and screening technologies mean that cervical cancer is now largely preventable, and the study finds encouraging decreases in some high-income countries following successful implementation of HPV vaccination programmes and screening. These high-income countries include Sweden, Australia and the United Kingdom.
Singh added that however, the burden remains high globally. He said that women all over the world should be free from the risk of preventable cancer.
How the study was conducted
The study authors estimated the burden of cervical cancer incidence and mortality rates in 185 countries using IARC’s GLOBOCAN 2020 database. The authors also analysed the relationship between cervical cancer cases and deaths in relation to national levels of socioeconomic development. They observed data from 1988 to 2017 to identify the trends of increase and decrease of cervical cancer cases.
Rates of cervical cancer incidence and deaths in 2020
The rates of cervical cancer cases were 13 per 100,000 women per year in 2020. The same year, the death rate was seven per 100,000 women.
According to the study, incidence rates of cervical cancer in 172 out of 185 countries still exceeded the four cases per 100,000 women per year threshold for elimination set by the WHO.
The researchers compared the rates of cervical cancer cases and deaths between different countries. They observed that there was a 40 times difference in cases, and 50 times difference in deaths in some countries.
The incidence rates were as low as two cases in Iraq per 100,000 women per year, and as high as 84 cases in Eswatini per 100,000 women per year.
The mortality rate in Switzerland was one death per 100,000 women per year, while that in Eswatini was 56 deaths per 100,000 women per year.
Higher rates of cervical cancer incidence and mortality were observed in countries with lower socioeconomic development.
Countries with largest declines and increases in incidence rates
Brazil, Slovenia, Kuwait, and Chile were the countries with the largest average declines in incidence rates per year, while Latvia, Japan, Ireland, Sweden, Norway, Northern Ireland, Estonia, and China were the countries with the highest increases in incidence rates per year, from 1988 to 2017.
Much work has to be done before 2030 for cervical cancer elimination
Dr Valentina Lorenzoni, one of the authors on the paper, said there is still much work to be done before 2030, because cervical cancer cases are much higher than the threshold agreed by the WHO initiative on cervical cancer elimination in most countries. She said that while a decrease in screening intensity due to the Covid-19 pandemic might have left a new group of susceptible women, the pandemic also boosted the introduction of self-administered HPV testing. This offers new possibilities to increase screening coverage.
Advancements such as thermal ablation (destruction of tissue by extreme hyperthermia or hypothermia) for treating cervical pre-cancer, the use of mobile phones to improve follow-up after screening, and machine learning to improve virtual assessment can be used in low resource settings to lower cervical cancer rates.
The authors noted some limitations to the study, including the fact that some data may be incomplete or inaccurate. In countries without effective screening programmes, cervical cancer cases may have appeared low.