Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2022 Jan 17;12(1):e052376.
doi: 10.1136/bmjopen-2021-052376.

Age-standardised incidence rate and epidemiology of colorectal cancer in Africa: a systematic review and meta-analysis

Nina Arhin #  1 , Paddy Ssentongo #  2 , Morris Taylor  3 , Elizabeth Josephine Olecki  4 , Colette Pameijer  4 , Chan Shen  4 , John Oh  4 , Cathy Eng  1
Affiliations
Meta-Analysis

Age-standardised incidence rate and epidemiology of colorectal cancer in Africa: a systematic review and meta-analysis

Nina Arhin et al. BMJ Open. .

Abstract

Objectives: Colorectal cancer (CRC) is the second-leading cause of cancer deaths globally, with low-income and middle-income countries (LMICs) disproportionately affected. Estimates of CRC rates in LMIC are scarce. We aimed to (1) estimate sex-specific incidence of CRC, (2) estimate temporal trend and (3) determine regional variations of CRC rates on the African continent.

Design: Systematic review and meta-analysis METHODS: PubMed (MEDLINE), OVID (MEDLINE), Scopus and Cochrane Library databases were systematically searched from inception to 12 December 2020. We included population-based studies that reported the incidence or prevalence estimates of CRC in Africa. Studies not conducted in humans or did not directly report the rates of CRC were excluded. Random effects model was used to pool the estimates. The methodological quality of studies was assessed with the Newcastle-Ottawa Scale.

Outcome measures: Overall and sex-specific annual age-standardised incidence rates (ASIR) of CRC per 100 000 population.

Results: The meta-analysis included 14 studies consisting of 3365 individuals with CRC (mean age, 58 years, 53% male). The overall ASIR of CRC in Africa per 100 000 population was 5.25 (95% CI 4.08 to 6.75). The rates were slightly higher in males (4.76) than in females (4.18), but not significantly different. Subgroup analysis indicated greater point estimates in North Africa (8.66) compared with sub-Saharan Africa (5.91); and higher estimates in Eastern (8.29) and Northern (8.66) Africa compared with Western (3.55) and Southern (3.57) Africa, but not statistically significant. The overall trend in ASIR has remained constant at nearly 5 per 100 000 population for the last 6 decades.

Conclusion: CRC estimates in Africa are heterogeneous and could be underestimated. High-quality data collection systems such as population-based cancer registries may facilitate accurate estimation of country-specific rates and provide critical information which would be lucrative to the consideration of resources needed for screening, early detection, treatment and improving overall patient outcomes.

Keywords: cancer pain; epidemiology; public health.

PubMed Disclaimer

Conflict of interest statement

Competing interests: None declared.

Figures

Figure 1
Figure 1
PRISMA flow chart of a systematic review of colorectal cancer incidence in Africa. PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.
Figure 2
Figure 2
Overall and sex-specific annualised age-standardised incidence rates (ASIR) of colorectal cancer in Africa. Event values represent the ASIR of colorectal cancer per 100 000 population. Blue squares and their corresponding lines are the point estimates and 95% CIs. Maroon diamonds represent the pooled estimate of the ASIR, overall and by sex (width denotes 95% CI). Although not statistically significant, the pooled ASIR of colorectal cancer in Africa was higher in males (I2=39) than in females (I2=37). P for interaction comparing the different subgroups=0.37.
Figure 3
Figure 3
Overall age-standardised incidence rates (ASIR) (per 100 000 population) of colorectal cancer in Africa stratified by United Nations region (North Africa and sub-Saharan Africa). Event values represent the ASIR of colorectal cancer per 100 000 population. Blue squares and their corresponding lines are the point estimates and 95% CIs. Maroon diamonds represent the pooled estimate of the ASIR, overall and by United Nations regions (width denotes 95% CI). Although not statistically significant, the pooled ASIR of colorectal cancer in Africa was higher in North Africa (I2=76) than SSA (I2=45). P for interaction comparing the different subgroups=0.21. SSA, sub-Saharan Africa.
Figure 4
Figure 4
Age-standardised incidence rates (ASIR) (per 100 000 population) of colorectal cancer in Africa stratified by United Nations subregions (Northern, Western, eastern and southern Africa). Event values represent the ASIRs of colorectal cancer per 100 000 population. Blue squares and their corresponding lines are the point estimates and 95% CIs. Maroon diamonds represent the pooled estimate of the ASIR, overall and by United Nations subregion (width denotes 95% CI).
Figure 5
Figure 5
Age-standardised incidence rates (ASIR) (per 100 000 population) of colorectal cancer in Africa stratified by year of study (before 2000 and before, 2000 and after). Event values represent the ASIRs of colorectal cancer per 100 000 population. Blue squares and their corresponding lines are the point estimates and 95% CIs. Maroon diamonds represent the pooled estimate of the ASIR, overall and by year categorised as before and after 2000 (width denotes 95% CI). There is no difference in the rates between the year categories.
Figure 6
Figure 6
Temporal trends in the incidence rates (per 100 000 population) of colorectal cancer in Africa. Rates were constant over time. UN, United Nation.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Bray F, Ferlay J, Soerjomataram I, et al. . Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2018;68:394–424. 10.3322/caac.21492 - DOI - PubMed
    1. Arnold M, Sierra MS, Laversanne M, et al. . Global patterns and trends in colorectal cancer incidence and mortality. Gut 2017;66:683–91. 10.1136/gutjnl-2015-310912 - DOI - PubMed
    1. Negin J, Cumming R, de Ramirez SS, et al. . Risk factors for non-communicable diseases among older adults in rural Africa. Trop Med Int Health 2011;16:640–6. 10.1111/j.1365-3156.2011.02739.x - DOI - PubMed
    1. Anoba IB. How a population of 4.2 billion could impact Africa by 2100: the possible economic. The SAIS Review of International Affairs, 2019.
    1. Graham A, Adeloye D, Grant L, Davies Adeloye LG, Theodoratou E, et al. . Estimating the incidence of colorectal cancer in sub-Saharan Africa: a systematic analysis. J Glob Health 2012;2:020404. 10.7189/jogh.02.020404 - DOI - PMC - PubMed
-