Cancer is arguably the biggest medical problem of the 21st century – but whose problem is it?
The other day, I was talking to a group of friends during lunchtime about the demographics of cancer incidence. In the midst of the discussion, a postdoctoral cancer researcher walked in to microwave his lunch. Overhearing the conversation, he shyly intervened, “Sorry to interrupt, but when you think about it, cancer is generally a problem of the wealthy, isn’t it?” Intrigued by the comment, I decided to spend the next few days investigating whether this was, in fact, the case.
As it turns out, the statistics provided by the World Health Organization (WHO) indicate that my colleague was wrong. The annual number of global cancer cases, which punched in at 14 million in 2012, is expected to rise to 22 million within the next two decades. Over 60% of these new cases – and 70% of all cancer-related deaths – will occur in Africa, Asia, and the Central and South Americas. Moreover, certain viral infections are more prevalent in low-income countries (LIC) and more likely to lead to cancer. For example, human papilloma virus infections (HPV), together with hepatitis B and C infections, contribute to as much as 20% of the cancer deaths in low and middle income countries.
So why is cancer often thought of as a problem of the privileged? A large part of the reason for this paradigm is that the general population of high-income countries (HIC) often has a higher life expectancy, and the risk of developing cancer increases with age. According to WHO, a girl born in Japan today can expect to live to 85 years-old with sufficient food, health care, and education, and have $550 a year on average to spend on medication, whereas a girl born in Sierra Leone can only expect to live until 38.
However, with the advent of better vaccinations and global disease management strategies, the average life expectancy in many LIC has increased drastically. According to Clio Infra – a Netherlands-based database – countries such as South Korea, Ethiopia, and India have seen a significant increase in the average age of their populations since the mid-20th century. And as the life expectancy rises, so does the incidence of cancer.
The limited availability of medical technology and health professionals, as well as the resultant underreporting of cancer cases, also plays an integral part in the discrepancy between the perceived and actual cancer incidence in LIC. Two-thirds of the world lacks access to basic medical imaging. While people in HIC have 1,700 X-ray scans per 1000 persons per year, only 30 people per 1000 in LIC have access to this technology. This lack of imaging technology reinforces the idea that there is a lower incidence of cancer – since there are fewer cancer diagnoses – while also contributing to the higher number of cancer fatalities due to less early detection of abnormal tissue growth.
Furthermore, current cancer research focusses disproportionately on cancers that affect HIC. According to the American Cancer Society – arguably the largest cancer-related funding agency in the world – there were 816 grants for cancer research as of August 1st, 2015. 198 of them, worth over $83 million, have gone towards breast cancer research, whereas only 2 of the 816 grants have been awarded to study pharyngeal cancer – a type of cancer that occurs 3 times as often in LIC compared to HIC.
In the past few decades, cancer has emerged as a global epidemic. While academic and medical efforts in the 20th century helped alleviate many of the acute diseases that disproportionately affect LIC, it is clear that the current medical efforts in LIC need to shift to a new paradigm, one that includes screening for and treating diseases (such as cancer) that develop later in life.
The next time I saw my postdoc colleague in the lunchroom, I said to him, “To answer your question from a few days ago: I did some research and cancer is actually damaging low-income regions of the world the most.” He nodded and replied, “That’s why I’m here trying to find solutions.”
- de Martel C, et al. (2012). “Global burden of cancers attributable to infections in 2008: a review and synthetic analysis.” The Lancet Oncology. 13: 607-615.
- Maru, DS, et al. (2010). “Turning a blind eye: the mobilization of radiology services in resource-poor regions.” Globalization and Health. 6: 18.
- Mason, B. (2004). “World health report: Life expectancy falls in poorest countries.” World Socialist Web Site.
- World Cancer Report 2014. World Health Organization.
- World Radiography Day: Two-thirds of the world’s population has no access to diagnostic imaging. PAHO WHO.