The World Health Organization says about half a million Africans die of cancer each year, or six percent of global cancer deaths annually.
The leading cancers in Africa affect the breast, cervix and prostate, according to WHO.
Dr. Andre Ilbawi, the technical officer for cancer control at WHO headquarters in Geneva, says the cause of the illness in Africa is not always clear, though factors that may contribute to breast cancer include alcohol use, obesity and lack of physical activity.
Weakened immune systems also play a role, making people susceptible to many infections and diseases, including the human papilloma virus, or HPV, which can cause cervical cancer.
"Women in Africa have a higher rate of HIV, which makes worse the effect of HPV," Ilbawi said, "so we see the combination of infectious causes really can explain the majority of cervical cancer cases in Africa and elsewhere."
Ilbawi says other infections, besides HPV, also can lead to cancer.
"We know the immune system plays a very important role in fighting cancer. And in some situations, infections can cause cancer themselves," he said. "It's not always as easy as saying malaria triggers cancer years down the line for someone exposed to malaria, but we do know there are some cause and effects for infectious causes of cancer in Africa. Some include hepatitis B and C, [which] contribute to liver cancer. … There are infections in the stomach that can contribute to gastric cancer … so infections both directly and by weakening the immune system can contribute to cancer cases."
Not all cancers are fatal, especially if detected early. The WHO is working to encourage governments to adopt measures that are low cost, but high impact, especially on the local, or primary care, level.
"Early diagnosis has a strategic position in health expenditures because if we are able to detect cancer early, then the costs of treatment are lower," Ilbawi said. "We know from high-income countries that detecting cancer at stage one or two [out of four] reduces the cost of treatment between two- to four-fold in some settings."
He also says earlier detection makes it likely that less toxic medications can be used.
WHO guidelines suggest inexpensive ways to improve cancer detection, beginning by educating the public and health workers on how to recognize potential symptoms.
"We need that provider to identify high-risk symptoms and say to a patient, 'I understand you are having bleeding in your stool or a lump or mass that may be concerning to you. It could be many possible diseases. But what you need to do is get from the primary care level to the diagnostic facilities, where you can access biopsy and pathology to confirm whether it's cancer,'" Ilbawi said.
"The first-level provider is critical because that's where most patients go first. And we have to bring those providers into the health system for cancer — not just focus on high-cost treatment at a centralized facility when most people can't get there, can't afford those treatments or get there far too late," he added.
Other low-cost options include providing social workers and patient navigators who can help direct patients to facilities that provide blood and tissue testing — and treatment.
Ilbawi says therapies for cancer patients do not have to be costly. They might involve surgery, chemotherapy, and oral and hormonal treatments.
The WHO advises countries on how to improve cancer care, including insurance and other mechanisms that make treatment more affordable.
Ibawi says it's a coordinated effort that includes governments, advocacy groups, the U.N. and donors. Together, they help identify where strategic investments can help improve health services and extend the lives of hundreds of thousands of people.