This article provides an update on the global cancer burden using the GLOBOCAN 2020 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer. Worldwide, an estimated 19.3 million new cancer cases (18.1 million excluding nonmelanoma skin cancer) and almost 10.0 million cancer deaths (9.9 million excluding nonmelanoma skin cancer) occurred in 2020. Female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases (11.7%), followed by lung (11.4%), colorectal (10.0 %), prostate (7.3%), and stomach (5.6%) cancers. Lung cancer remained the leading cause of cancer death, with an estimated 1.8 million deaths (18%), followed by colorectal (9.4%), liver (8.3%), stomach (7.7%), and female breast (6.9%) cancers. Overall incidence was from 2-fold to 3-fold higher in transitioned versus transitioning countries for both sexes, whereas mortality varied <2-fold for men and little for women. Death rates for female breast and cervical cancers, however, were considerably higher in transitioning versus transitioned countries (15.0 vs 12.8 per 100,000 and 12.4 vs 5.2 per 100,000, respectively). The global cancer burden is expected to be 28.4 million cases in 2040, a 47% rise from 2020, with a larger increase in transitioning (64% to 95%) versus transitioned (32% to 56%) countries due to demographic changes, although this may be further exacerbated by increasing risk factors associated with globalization and a growing economy. Efforts to build a sustainable infrastructure for the dissemination of cancer prevention measures and provision of cancer care in transitioning countries is critical for global cancer control.

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.3322/caac.21660

Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries.

With the cancer burden rising in sub-Saharan Africa, countries in the region need surveillance systems to measure the magnitude of the problem and monitor progress in cancer control planning. Based on the national estimates built from data provided by cancer registries in sub-Saharan Africa, we summarise key patterns of the regional burden and argue for investments in locally produced data.To present national estimates of the cancer incidence and mortality burden in sub-Saharan Africa countries, new cancer cases and deaths were extracted from International Agency for Research on Cancers' GLOBOCAN database for the year 2020. Given weak vital statistics systems, almost all of the information on the cancer burden in sub-Saharan Africa was derived from population-based cancer registries. Of the 48 countries included in GLOBOCAN (national populations must be larger than 150 000 inhabitants in 2020), relatively recent cancer registry data (up to 2019) were directly used to produce national incidence estimates in 25 countries, while the absence of such data for 16 meant that estimates were based on data from neighbouring countries. Tables and figures present the estimated numbers of new cases and deaths, as well as age-standardised (incidence or mortality) rates per 100 000 person-years and the cumulative risk of developing or dying from cancer before the age of 75 years.801 392 new cancer cases and 520 158 cancer deaths were estimated to have occurred in sub-Saharan Africa in 2020. Cancers of the breast (129 400 female cases) and cervix (110 300 cases) were responsible for three in ten of the cancers diagnosed in both sexes. Breast and cervical cancer were the most common cancers, ranking first in 28 and 19 countries, respectively. In men, prostate cancer led in terms of incidence (77 300 cases), followed by liver cancer (24 700 cases) and colorectal cancer (23 400 cases). Prostate cancer was the leading incident cancer in men in 40 sub-Saharan Africa countries. The risk of a woman in sub-Saharan Africa developing cancer by the age of 75 years was 14·1%, with breast cancer (4·1%) and cervical cancer (3·5%) responsible for half of this risk. For men, the corresponding cumulative incidence was lower (12·2%), with prostate cancer responsible for a third of this risk (4·2%). Cervical cancer was the leading form of cancer death among women in 27 countries, followed by breast cancer (21 countries). Prostate cancer led as the most common type of cancer death in 26 countries, with liver cancer ranking second (11 countries).The estimates indicate substantial geographical variations in the major cancers in sub-Saharan Africa. Rational cancer control planning requires capacity to be built for data production, analysis, and interpretation within the countries themselves. Cancer registries provide important information in this respect and should be prioritised for sustainable investment in the region.None. 

Cancer in sub-Saharan Africa in 2020: a review of current estimates of the national burden, data gaps, and future needs.

Objective Cancer incidence and mortality rates in Africa are increasing, yet their geographic distribution and determinants are incompletely characterized. The present study aims to establish the spatial epidemiology of cancer burden in Africa and delineate the association between cancer burden and the country-level socioeconomic status. The study also examines the forecasts of the cancer burden for 2040 and evaluates infrastructure availability across all African countries. Methods The estimates of age, sex, and country-specific incidence and mortality of 34 neoplasms in 54 African countries, were procured from GLOBOCAN 2020. Mortality-to-incidence ratio (MIR) was employed as a proxy indicator of 5-year survival rates, and the socioeconomic development of each country was measured using its human development index (HDI). We regressed age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), and MIR on HDI using linear regression model to determine the relationship between cancer burden and HDI. Maps were generated for each cancer group for each country in Africa. The data about the cancer infrastructure of African countries were extracted from the WHO Cancer Country Profiles. Results In Africa, an estimated 1.1 million new cases [95% uncertainty intervals (UIs) 1.0 – 1.3 million] and 711,429 [611,604 – 827,547] deaths occurred due to neoplasms in 2020. The ASIR was estimated to be 132.1/100,000, varying from 78.4/100,000 (Niger) to 212.5/100,000 (La Réunion) in 2020. The ASMR was 88.8/100,000 in Africa, ranging from 56.6/100,000 in the Republic of the Congo to 139.4/100,000 in Zimbabwe. The MIR of all cancer combined was 0.64 in Africa, varying from 0.49 in Mauritius to 0.78 in The Gambia. HDI had a significant negative correlation with MIR of all cancer groups combined and main cancer groups (prostate, breast, cervical and colorectal). HDI explained 75% of the variation in overall 5-year cancer survival (MIR). By 2040, the burden of all neoplasms combined is forecasted to increase to 2.1 million new cases and 1.4 million deaths in Africa. Conclusion High cancer mortality rates in Africa demand a holistic approach toward cancer control and management, including, but not limited to, boosting cancer awareness, adopting primary and secondary prevention, mitigating risk factors, improving cancer infrastructure and timely treatment.

Mapping Cancer in Africa: A Comprehensive and Comparable Characterization of 34 Cancer Types Using Estimates From GLOBOCAN 2020

Cancer disproportionately affects patients in lowand middle-income countries, with 70% of newly diagnosed cancer cases occurring in lowand middleincome countries where the survival rate of cancer is 30% to 50% lower than that of high-income countries. Although Africa only accounts for approximately 6% of the world cancer burden, it is not a rare disease on the continent, as is sometimes supposed. The economic and social burdens it brings upon the population are enormous. To overcome this rapidly rising problem, countries in sub-Saharan Africa (SSA) urgently need rational national cancer control planning.

Population-Based Cancer Registration in Sub-Saharan Africa: Its Role in Research and Cancer Control

Background Mortality rates from cervical cancer demonstrate deep inequality in health between richer and poorer populations. Over 310 000 women died of this preventable disease in 2018, mostly in low-income and middle-income countries (LMICs) where screening and treatment are beyond the capacity of health systems. Immunisation against human papillomavirus (HPV) offers a primary prevention strategy, but rates of vaccination uptake are unclear. Understanding coverage levels and factors affecting uptake can inform immunisation strategies. Objectives The aim of this study is to evaluate the status of HPV vaccination coverage from nationally reported indicators and to estimate global coverage in a single year cohort of vaccine-eligible girls. Design This study provides quantitative population-level estimates of important global health indicators. Using data from the Global Cancer Observatory and WHO/UNICEF, incidence of and mortality from cervical cancer and HPV vaccination coverage are described for countries, categorised by income group. Characteristics of LMICs achieving high coverage are explored using selected development indicators from World Bank sources. Global HPV immunisation coverage is calculated and its impact on cervical cancer mortality estimated. Results Incidence and mortality for cervical cancer correlate with poverty. Whilst all WHO member states report high infant measles vaccination rates, fewer than half report on HPV vaccination. Even amongst high-income countries, coverage varies widely. In upper-middle-income countries, there is a trend for higher coverage with increased health spending per capita. Four LMICs report good coverage levels, all associated with external funding. Global HPV immunisation coverage for 2018 is estimated at 12.2%. Of the global cohort of 61 million 15-year-old girls in 2018, 7000 are likely to die from cervical cancer, almost all in LMICs. Conclusions Countries in all income groups must devise strategies to achieve and maintain higher levels of HPV immunisation. For all but the richest, affordability remains a barrier.

https://bmjopen.bmj.com/content/bmjopen/11/9/e052016.full.pdf

Estimate of global human papillomavirus vaccination coverage: analysis of country-level indicators.

Cervical cancer is the second most common cancer and the leading cause of cancer death in women in sub-Saharan Africa (SSA). Trends in the incidence of cervical cancer are examined for a period of 10–25 years in 10 population-based cancer registries across eight SSA countries (Gambia, Kenya, Malawi, Mauritius, Seychelles, South Africa, Uganda and Zimbabwe). A total of 21,990 cases of cervical cancer were included in the analyses. Incidence rates had increased in all registries for some or all of the periods studied, except for Mauritius with a constant annual 2.5% decline. Eastern Cape and Blantyre (Malawi) registries showed significant increases over time, with the most rapid being in Blantyre (7.9% annually). In Kampala (Uganda), a significant increase was noted (2.2%) until 2006, followed by a non-significant decline. In Eldoret, a decrease (1998–2002) was followed by a significant increase (9.5%) from 2002 to 2016. Overall, cervical cancer incidence has been increasing in SSA. The current high-level advocacy to reduce the burden of cervical cancer in SSA needs to be translated into support for prevention (vaccination against human papillomavirus and population-wide screening), with careful monitoring of results through population-based registries.

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Walburga Yvonne Joko

Papers

Trends in cervical cancer incidence in sub-Saharan Africa.