Cancer is an emerging public health problem in Africa. According to the International Agency for Research on Cancer (IARC), about 715,000 new cancer cases and 542,000 cancer deaths occurred in 2008 in Africa. These numbers are projected to nearly double (1.28 million new cancer cases and 970,000 cancer deaths) by 2030 simply due to the aging and growth of the population, with the potential to be even higher because of the adoption of behaviors and lifestyles associated with economic development, such as smoking, unhealthy diet, and physical inactivity.
Despite this growing burden, cancer continues to receive low public health priority in Africa, largely because of limited resources and other pressing public health problems, including communicable diseases such as acquired immune deficiency syndrome (AIDS)/human immunodeficiency virus (HIV) infection, malaria, and tuberculosis. It may also be in part due to a lack of awareness about the magnitude of the current and future cancer burden among policy makers, the general public, and international private or public health agencies. This article summarizes available information on cancer occurrence, risk factors, screening, and treatment in Africa in order to raise cancer awareness and promote cancer prevention and control in the region.
In Africa, cancers related to infectious agents (cervix, liver, Kaposi sarcoma, urinary bladder) are among the dominant types of the disease in Africa. In 2008, cervical cancer accounted for 21% of the total newly diagnosed cancers in females and liver cancer for 11% of the total cancer cases in males. In contrast, cancers related to tobacco use (e.g., lung), reproductive behaviors (female breast), dietary patterns and obesity (e.g., colorectal), and screening or diagnostic services (prostate) are the most common cancers in North America. However, such cancers are also becoming more common in developing countries due to the adoption of unhealthy behaviors and lifestyles associated with economic development, such as smoking, physical inactivity, and consumption of calorie-dense food. For example, prostate cancer in men and breast cancer in women have now become the most commonly diagnosed cancers in some parts of Africa.
Tobacco use is the most preventable cause of cancer death, accounting for 20% of cancer deaths worldwide and for about 6% of cancer deaths in Africa. The smaller contribution of tobacco use to cancer deaths in Africa reflects the early stage of the tobacco epidemic and low smoking prevalence, especially in women. Adult smoking prevalence is less than 10% in men and 2% in women in many African countries, including Nigeria and Ethiopia, the two most populous nations on the continent. However, cigarette consumption is increasing in this region due to the adoption of new behaviors associated with economic growth and increased marketing by tobacco companies.46 The smoking pattern among teens is even more disturbing. According to the Global Youth Tobacco Survey, in some African countries, the smoking prevalence among boys is higher than among adults. In response to the globalization of the tobacco epidemic, the WHO established the Framework Convention on Tobacco Control (FCTC), which features internationally coordinated provisions to control tobacco that include raising the price of tobacco products, banning smoking in public places, restricting tobacco advertising and promotion, counter-advertising, and providing treatment and counseling for tobacco dependence.
Unhealthy diet, physical inactivity, and obesity have been associated with increased risk of several cancers, including breast, colorectal, stomach, liver, kidney, and uterine corpus. The prevalence of obesity and physical inactivity is increasing in several African countries, especially in urban areas, as a result of increased consumption of calorie-dense food and declines in energy expenditures at work and in daily life. For example, according to a 2003 survey in four urban districts of Cameroon, more than 25% of men and almost 50% of women were overweight or obese, and 6.5% of men and 19.5% of women were obese. Notably, according to the Global School-Based Student Health Survey, more than 40% of 13- to 15-year-old teens in urban areas of Kenya and Zimbabwe spent three or more hours per day watching television and doing other sedentary activities. The WHO developed a global strategy to improve dietary patterns and physical activity through the development of national-, regional-, and/or community-level policies and programs that are comprehensive and sustainable. Some countries in the WHO African Region, including Algeria, Mauritius, and South Africa, have implemented this strategy, with a focus on promoting physical activity. In school-based HIV/AIDS prevention projects in Benin and Burundi, there are efforts to incorporate prevention measures for non-communicable diseases (noninfectious diseases), such as increasing physical activity, eating a healthy diet, and not smoking.
Cancer prevention and control using standard screening methods, such as mammography for breast cancer, fecal occult blood testing and sigmoidoscopy/colonoscopy for colorectal cancer, and Pap testing for cervical cancer, are not only cost prohibitive in most parts of Africa, but they are also not supported by the existing health care infrastructure. However, early detection for cervical cancer or precancerous lesions by visual inspection using Lugol’s iodine or acetic acid and low-cost DNA tests to detect HPV infections have been shown to be feasible and effective in many parts of Africa, including Kenya and South Africa. Previous studies based on simulation modeling have reported that screening once or twice in a lifetime between ages 35-55 using these low-cost/low-tech screening methods can reduce cervical cancer by about 30%. Early detection is the only viable option for reducing the currently high cervical cancer burden in sub-Saharan Africa because the available vaccines are only recommended for adolescent girls. Screening would be appropriate even for vaccinated girls once they reach the recommended screening age since the vaccines do not provide protection for 30% of chronic human papillomavirus (HPV) infections that cause cervical cancer.
Increasing public awareness of early signs and symptoms of cancers of the breast, cervix, colorectum, oral cavity, urinary bladder, and prostate may increase detection of these diseases at earlier stages when there are more options for treatment and survival rates are higher. Every effort must be made to expand the capacity of health care delivery systems to provide timely and effective treatment to patients diagnosed with early stage disease in order for increased awareness initiatives to result in improved patient outcomes.
The writer is Abdul Samed Zurak.
He is the Chairman/Founder of Zurak Cancer Foundation.
Contact him through his email on firstname.lastname@example.org