Why you should care
Because cancer is no longer an “affliction of affluence.”
In the United States, pink ribbons and Movember mustaches flood social-media feeds to raise awareness of breast and prostate cancer, respectively. But in the global south, cancer is different. For starters, it’s often linked to infectious diseases. And more strikingly, it’s now home to the majority of cancer cases.
A staggering 83 percent of liver cancer cases emerged in the developing world in 2012, according to the International Agency for Research on Cancer.
What’s more, liver cancer in poor countries tends to look different. In the West, it typically emerges in men over the age of 40 with chronic liver disease. That’s not always so in the developing world. In Peru, for instance, liver cancer tends to strike youth around age 25 — sans liver disease. Aflatoxin, a substance produced by molds on peanuts and corn, may play a role. Viral hepatitis most certainly does. Mongolia has the highest rate of liver cancer in the world, which researchers attribute to the spread of hepatitis in the 1970s and 1980s, before the debut of disposable syringes in the country. While global health programs have made hepatitis B vaccines more accessible in low-income countries, whether they’re administered appropriately remains “a subject of greater debate,” says André Ilbawi of the World Health Organization.
Poor diagnostics complicate matters. Liver cancer is typically diagnosed with MRI and CT scanners, a biopsy or a blood test — which may require resources and expertise that are not readily available in low-income countries. Some researchers are looking for a different way. Ahmed El Kaffas, a postdoctoral researcher at Stanford University School of Medicine, is developing an affordable, portable, ultrasound diagnostic — currently about the size of a suitcase — to identify those at risk for liver cancer in rural villages in his native Egypt. El Kaffas’ device measures parameters from the frequency spectrum of ultrasound signals bouncing back from liver tissue, which depend on whether the tissue is diseased or healthy.
As she describes in her TED talk above, MIT bioengineer Sangeeta Bhatia has set her sights even smaller — with a paper cancer diagnostic that would work a bit like a pregnancy test. Small as it is, the diagnostic she envisions is not necessarily simple. It involves nanoparticles that would be activated by enzymes that digest the tissue scaffolds encapsulating the tumor. She would inject these nanoparticles into a patient’s bloodstream and wait about an hour for them to leak into the tumor, become activated, pass through the urine and get detected by a specially coated paper strip. Bhatia has also engineered bacteria commonly found in yogurt to churn out the urine signal, suggesting that a dollop of yogurt might offer an alternative to injection.
But “we want to be careful not to overpromise,” Bhatia cautions. Ilbawi adds that any new technology needs to be part of a larger healthcare system equipped to provide comprehensive care. And of course, like many of those focusing on the global south, they may face scarce funding and other support. Swimming in Facebook status updates, many have an out-of-sight, out-of-mind outlook. They might scoff, “It’s just Peru,” says Stéphane Bertani, who researches liver cancer there for the Research Institute for Development. “But they’re human beings too.”