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Cervical Cancer in Africa
Across Africa as a whole, 79,000 women every year are diagnosed with cervical cancer and 62,000 will die from the disease. Cervical cancer is the number one cancer killer in women across Africa, and the majority of women who die from the disease are below the age of 55 (Ferlay et al 2004).
(Reference: Ferlay et al 2004)
The prevalence of cervical cancer varies across Africa. For example, the 1-year prevalence in Tanzania is 23.1 women per 100,000. This figure is slightly lower in Zimbabwe (16.3 per 100,000) and Zambia (17.8 per 100,000), and significantly lower in Morocco (5.7 per 100,000) and Tunisia (3.5 per 100,000) (derived from Ferlay et al 2004).
The highest age-standardised incidences of cervical cancer are again seen in countries such as Tanzania (68.6 cases per 100,000 women per year), Zimbabwe (52.1 per 100,000) and Zambia (53.7 per 100,000), with the lowest rates in countries such as Morocco (13.2 per 100,000) and Tunisia (8.6 per 100,000).
(Reference: Ferlay et al 2004)
Age-standardised mortality rates show a similar distribution to prevalence and incidence across Africa, with high rates of deaths from cervical cancer in Tanzania (55.6 deaths per 100,000 women per year), Zimbabwe (43.1 per 100,000) and Zambia (44.0 per 100,000), and lower rates in Morocco (10.7 per 100 000) and Tunisia (5.5 per 100,000) (Ferlay et al 2004).
Geographical trends in prevalence, incidence and mortality are similar across Africa, and regional variations are most likely due to a combination of factors.
- One such factor is differences in availability and extent of cervical screening, which can help to identify and treat cervical abnormalities before the development of invasive cervical cancer (Schiller and Davies 2004; Franco et al 2001).
- Societal differences may also account for some of the country-by-country variation in cervical cancer rates across Africa. Countries in North Africa with predominantly Muslim populations often display low rates of the disease (Maalej et al 2004), an effect which persists even after migration away from North Africa (Bouchardy et al 1996). This reduced incidence of cervical cancer may be related to the fact that Muslim men in particular are likely to have had fewer sexual partners before marriage, and are therefore at a lower risk of HPV infection, although a direct causal link between these factors has not been demonstrated (Duttagupta et al 2004).
- A third factor is the presence of co-morbid HIV infection, which is highly prevalent in many parts of Africa. HIV co-infection suppresses the immune system, thereby increasing the likelihood of a HPV infection becoming persistent, and increasing a woman’s risk of developing pre-cancerous abnormalities or invasive cervical cancer (Harris et al 2005; Nicol et al 2005).
While conventional cervical screening may not be a cost-effective option in many countries across Africa, visual screening followed by treatment using the VIA “see and treat” method could help reduce the incidence of cervical cancer by treating cervical abnormalities before they are allowed to progress (Jacob et al 2005). However, the efficacy of the VIA screening method is not proven, and it is associated with low sensitivity and therefore high levels of over-treatment (Jacob et al 2005).