Author: Sierra Alef-Defoe
What is the main predictor of outcome for a child with cancer? Many would guess a characteristic of the cancer diagnosis or of the patient, such as the type of tumor or the age of the child. But these factors are secondary compared to where in the world the patient lives. In a high-income country (HIC), over 80% of children survive cancer. Meanwhile, only 20% of children in low- or middle-income countries (LMICs) survive. The majority of the world’s children — over 80% — live in LMICs, while fewer than 20% live in HICs. This “80/20 paradox” shows that childhood cancer is an important global health problem, and that pediatric oncology needs to embrace a global perspective.
A picture of childhood cancer in a LMIC
Imagine you’re an experienced cancer doctor, working in a public hospital in a capital city in a LMIC. A child presents to you with an abdominal tumor that you suspect is Burkitt lymphoma; a childhood cancer common in this setting. To confirm the diagnosis, you would like to do a biopsy and molecular profiling, but the laboratory equipment isn’t working — donated medical machinery that did not come with training or tools for maintenance. The palpable tumor presents a relatively simple case to diagnose compared to blood cancers which can more easily be mistaken for dengue fever or malaria. In LMICs, cancers of the blood, lymph (such as Burkitt), kidney, and eye are the most common in children.
Reasonably effective treatment for Burkitt lymphoma can cost less than 100 USD per patient. However, you are awaiting the supplier’s next shipment, and you already have patients waiting for those drugs. The drug supply chain poses a major challenge in LMICs, from refrigeration to financing. Access to radiotherapy, complex surgery, and palliation pose even larger challenges. Bone marrow transplantation, which is used to treat certain leukemias, is beyond reach for most of the world’s children.
You worry the child’s disease may be advanced due to delay in diagnosis. The parents explain that they took the child to a village healer when she first had symptoms. When the child’s condition didn’t improve, the family fundraised for months to make the 2-day bus trip to the hospital. In the time since the symptoms first presented, a treatable early stage tumor may have become a complicated metastatic disease. These diagnostic delays are common when resources and health literacy are limited.
The patient is underweight, as her father is out of work and can’t afford enough food for the family, which includes a mother also caring for three other siblings. Last year, the child suffered from a severe case of malaria. Malnutrition and infectious diseases are common in children with cancer in LMICs, making it harder for their bodies to tolerate intense cancer medicines.
It is challenging for the family to get to the hospital, and the financial burden is devastating, putting them at risk of treatment abandonment. If the family sees the child’s tumor shrink early on, or if she suffers from side effects, they may not travel back and pay for further treatment. This would put the child at risk of relapse, which could reinforce her community’s beliefs/suspicions that cancer is untreatable or that biomedicine doesn’t work.
The global burden of childhood cancer
Cancer incidence for all age groups is now higher in LMICs than in HICs, as they undergo an ‘epidemiological transition,’ where non-communicable diseases become more prominent as communicable diseases decline. But communicable diseases persist as well, imposing a double burden of disease. Rather than being secondary to communicable diseases, cancer is exacerbated by them — Epstein-Barr Virus, HIV, and hepatitis increase risk of Burkitt lymphoma, Kaposi sarcoma, and liver cancer, respectively.
The World Health Organization (WHO) estimates that globally, there are 300,000 cases of childhood cancer per year. These estimates are imprecise, given that most of the world’s children are not covered by reliable cancer registries. Modern simulations suggest that the incidence may be even higher, with as many as 43% of cases undiagnosed.
Of the estimated 100,000 cancer deaths in children globally, 90% are in LMICs. These children are 4 times more likely to die from cancer than their counterparts in HICs, a disparity that underlines the severe inequalities in child cancer outcomes around the world.
In the pediatric oncology sphere, we highlight our “international collaboration,” but it is mostly limited to the U.S., Canada, European countries, Japan, and Australia. These HICs, accounting for the minority of child cancers (2), produce the majority of research and recommendations. Virtually all cancer research is done in white populations without regard for genetic variation and environmental differences around the world. Just as “global health” grew from “international health” to reflect the nuances of health and disease worldwide, pediatric cancer must move from an international to a global approach.
While advancing health outcomes in LMICs is challenging, we know that it’s possible from the tremendous progress made in HIV/AIDS. The infrastructure built to fight HIV can also serve to fight child cancer, exemplifying how various disease interest groups can work in tandem to advance health outcomes.
In just one generation, high-income countries have seen child cancer advance from a terminal diagnosis to a largely treatable one. We have overcome the largest hurdle — today, we know how to treat most childhood cancers. We also know how to improve outcomes in LMICs; by research and training partnerships (twinning programs), cancer registries, health insurance schemes, and health system capacity building. Implementing proven solutions could take childhood cancer from terminal to treatable on a global scale.
In 2018, the WHO announced ambitious goals to double the child cancer cure rate by 2030. The pediatric oncology community should seize this attention and advance our work to a global scale. Likewise, global health experts should highlight pediatric oncology as an opportunity to tangibly improve children’s health outcomes worldwide. We can build a world where children with cancer can have the best care possible no matter where in the world they live.
With thanks to: Jeremy Slone and Bonkolab Writing Club