Where are all of the pediatric cancer patients?

There are times where new research completely changes the way one looks at a problem.  The two articles we discuss on this episode changed the way I think about global oncology.  Prior to reading the articles, if you asked me what is the most common reason for mortality in global pediatric oncology, I would have probably said substandard or unavailable care.  It’s been demonstrated over and over in the literature, as care quality improves, survival curves dramatically increase. However, this answer is likely wrong. The real answer is a patient not being diagnosed. As you will hear today, it is estimated that there are around 400,000 new cases of childhood cancer each year for kids ages 0-14, and 43% of of these kids are not being diagnosed and therefore not receiving any treatment at all.  43%! That amounts to between 180,000 – 200,000 patients per year going undiagnosed, and around 3 million going undiagnosed by 2030. For comparison, prior to this study the best estimates reported a global incidence of 224,000 per year, meaning we now think we are not diagnosing almost as many patients as the number of previously estimated total cases.  This is a public health catastrophe! This means that medical care availability and strong health systems that can accurately diagnose and refer pediatric patients with cancer are key to improving survival.

To better understand what these numbers mean and how they were estimated, I will be talking to two researchers, Dr. Jennifer Yeh and Zachary Ward, who together with their collaborators recently published papers in Lancet Oncology estimating global incidence and survival of childhood cancer using sophisticated simulation techniques.  Large scale simulations using super computers and fancy statistics may be new for many people in the medical field (including me) and understanding the reliability of these estimates may be difficult.  In this episode we will talk through not only the numbers the researchers reported, but how they went about calculating them, with the hope that the listener will come away with a better conceptual understanding of the techniques they used and greater confidence to interpret their findings for themselves.  This is not the last you will hear about these statistics.  In future episodes we are going to circle back around to these findings and discuss their implication for the biomedical side of global oncology as well as the public health and health policy sides, so stay tuned!

Paper 1 – Estimating the total incidence of global childhood cancer: a simulation-based analysis

Paper 2 – Global childhood cancer survival estimates and priority-setting: a simulation-based analysis

About the guests:

Dr. Jennifer Yeh, PhD is a decision scientist whose research focuses on improving health outcomes at the population level. She has extensive experience applying decision-analytic modeling and cost-effectiveness analysis methods to evaluate clinical guidelines and health policy. Her research focuses primarily on cancer control and spans across the cancer continuum, ranging from gastric cancer prevention to childhood cancer survivorship. Dr. Yeh has developed and applied methods of decision analysis, simulation modeling and economic evaluation to identify opportunities to enhance cancer screening and surveillance programs. In particular, she has developed novel approaches that incorporate the effects of early life exposures on long-term health outcomes. Her work on childhood cancer survivorship focuses on how treatment-related risks for secondary cancers, cardiac events and other late effects impact long-term health and quality of life. She was recently awarded a grant from the American Cancer Society to evaluate secondary cancer screening guidelines for childhood cancer survivors.

Dr. Yeh is an Assistant Professor of Pediatrics at Harvard Medical School and Associate Scientific Researcher in the Division of General Pediatrics at Boston Children’s Hospital. She graduated from the University of Colorado at Boulder with a B.A. in Biology, received an M.S. in Health Policy and Management from the Harvard T.H. Chan School of Public Health, and completed her doctorate from the Health Policy PhD program at Harvard University, concentrating in Decision Sciences. Upon completing a NCI-sponsored post-doctoral fellowship at the Harvard T.H. Chan School of Public Health and Dana Farber/Harvard Cancer Center, she was awarded a NCI K07 Career Development Award. She is a current recipient of an American Cancer Society Research Scholar Grant.


Zachary Ward, MPH is a decision scientist and PhD candidate with research interests in computational science and global health. His research has been published in journals such as the New England Journal of MedicineThe Lancet Oncology, and Health Affairs.

He has worked as a programmer/analyst at the Center for Health Decision Science at the Harvard T.H. Chan School of Public Health since 2011, and entered the Decision Sciences concentration of the Ph.D. Program in Health Policy at Harvard University in 2015.  He is also pursuing a secondary field in Computational Science and Engineering. He received his undergraduate degree in Global Health Management from Seattle Pacific University and his Masters of Public Health from l’Ecole des Hautes Etudes en Santé Publique (EHESP) in Paris, with a concentration in Epidemiology.

Originally from Kenya, Zach has worked with various community-based NGOs in Tanzania, Malawi, and Rwanda, creating health information systems and management tools.  At Harvard he has developed microsimulation models focused on various topics, including childhood obesity, childhood cancer, and maternal mortality.