Cancer in Africa: The Untold Story

Abstract

Background: Despite rising incidence and mortality rates in Africa, cancer has been given low priority in the research field and in healthcare services. Indeed, 57% of all new cancer cases around the world occur in low income countries exacerbated by lack of awareness, lack of preventive strategies, and increased life expectancies. Despite recent efforts devoted to cancer epidemiology, statistics on cancer rates in Africa are often dispersed across different registries. In this study our goal included identifying the most promising prevention and treatment approaches available in Africa. To do this, we collated and analyzed the incidence and fatality rates for the 10 most common and fatal cancers in 56 African countries grouped into 5 different regions (North, West, East, Central and South) over 16-years (2002-2018). We examined temporal and regional trends by investigating the most important risk factors associated to each cancer type. Data were analyzed by cancer type, African region, gender, measures of socioeconomic status and the availability of medical devices.

Results: We observed that Northern and Southern Africa were most similar in their cancer incidences and fatality rates compared to other African regions. The most prevalent cancers are breast, bladder and liver cancers in Northern Africa; prostate, lung and colorectal cancers in Southern Africa; and esophageal and cervical cancer in East Africa. In Southern Africa, fatality rates from prostate cancer and cervical cancer have increased. In addition, these three cancers are less fatal in Northern and Southern Africa compared to other regions, which correlates with the Human Development Index and the availability of medical devices. With the exception of thyroid cancer, all other cancers have higher incidences in males than females.

Conclusion: Our results show that the African continent suffers from a shortage of medical equipment, research resources and epidemiological expertise. While recognizing that risk factors are interconnected, we focused on risk factors more or less specific to each cancer type. This helps identify specific preventive and therapeutic options in Africa. We see a need for implementing more accurate preventive strategies to tackle this disease as many cases are likely preventable. Opportunities exist for vaccination programs for cervical and liver cancer, genetic testing and use of new targeted therapies for breast and prostate cancer, and positive changes in lifestyle for lung, colorectal and bladder cancers. Such recommendations should be tailored for the different African regions depending on their disease profiles and specific needs.

Keywords: Africa; cancer; epidemiology; human development index; incidence rates; medical devices; mortality rates; risk factors.

Figure 1

Incidence and fatality rates of breast cancer per 100,000 inhabitants from 2002 to 2018. IR refers to active cancer cases per year and per region per 100 000 inhabitants. The FR of a region per year is obtained by dividing the number of cancer deaths by the total number of active cancer cases per year in a specific region and multiplying by a hundred to give a percent. (A) Breast cancer incidence rates in the different African regions per 100,000. (B) Changes in incidence rate from 2002 to 2018. (C) Breast cancer fatality rates (percent mortality per year of those afflicted) in the different African regions given as a percent.

Figure 2

Incidence and fatality rate for prostate cancer per 100,000 inhabitant from 2002 to 2018 in Africa. (A) Prostate cancer incidence rates in the different African regions per 100,000 inhabitant. (B) Incidence rates from 2002 to 2018. (C) Prostate cancer fatality rates (percent mortality per year of those afflicted) in the different African regions.

Figure 3

Cervical cancer incidence and fatality rates in the different African regions. (A) Incidence of cervical cancer per 100,000 inhabitant by African regions. (B) Evolution of Incidence rates from 2002 to 2018. (C) Fatality rates (percent mortality per year of those afflicted) of cervical cancer.

Figure 4

Lung cancer incidence rates by African region, per year and by gender. (A) Incidence rate per 100,000 inhabitant by African regions. (B) Dynamics of Changes of incidence rates from 2002 to 2018. (C) Lung cancer Incidence rates by gender in different African regions. This represents the number of active cancer cases per year per 100,000 men and per 100,000 women in each African region.

Figure 5

Stomach cancer incidence rates by year, by African region and by gender. (A) Stomach cancer incidence per 100,000 inhabitant in African regions. (B) Dynamics of incidence rates from 2002 to 2018. (C) Stomach cancer incidence by gender.

Figure 6

Colorectal cancer incidence rates per year, by African region and by gender. (A) Colorectal cancer incidence rates per 100,000 inhabitant in different African regions. (B) Dynamics of incidence rates from 2002 to 2018. (C) Colorectal cancer Incidence rate by gender in Africa.

Figure 7

Esophageal cancer incidence rates per year, by African region and by gender. (A) Esophageal cancer incidence per 100,000 inhabitant in African regions. (B) Dynamics of incidence rates from 2002 to 2018. (C) Esophageal cancer incidence by gender.

Figure 8

Liver cancer incidence rates by year, by African region and by gender. (A) Liver cancer incidence rate per 100,000 inhabitant in different African regions. (B) Dynamics of the incidence from 2002 to 2018. (C) Liver cancer incidence by gender.

Figure 9

Bladder cancer incidence rates per year, by African region and by gender. (A) Bladder cancer incidence per 100,000 inhabitant in all Africa regions. (B) Dynamics of incidence rates from 2002 to 2018. (C) Bladder cancer incidence by gender.

Figure 10

Thyroid cancer incidence rates per year, by African region and by gender. (A) Incidence rates per 100,000 inhabitant in different African regions. (B) Dynamics of the incidence from 2012 to 2018. (C) Thyroid cancer incidence rates by gender in Africa.

Figure 11

Cancer Medical devices per 1,000,000 inhabitants. These include the following medical devices: Mammographs, Computed Tomography, Magnetic Resonance Imaging, Positron Emission Tomography, Gamma Camera or Nuclear Medicine, Linear accelerator, Telecobalt unit, Radiotherapy. Source Global atlas of medical devices, World Health Organization, 2017.

Figure 12

Association between human development index (HDI) and cancer incidence and fatality rates for the five African regions in 2018. The data include fifteen points per graph resulting from three cancer types (breast, prostate and cervical) per region. (A) The relationship between HDI and cancer incidence rates is not significant and shows no trends other than higher variance among the cancer types for the two regions (Northern and Southern Africa) with the highest HDI. (B) Cancer fatality rates decline significantly with HDI for the three most frequent cancer types.

Figure 13

Distribution of the most frequent cancer types by African region. Different colors refer to the different African regions (North, East, West, Central and Southern Africa).