Genomic tools are helping to guide the search for new insights into uncommon childhood cancers like pediatric Acute Myeloid Leukemia (AML) and lymphomas — insights that, researchers hope, will improve survival rates and better spare survivors of childhood cancers from long-term treatment-associated health effects in adulthood, according to experts who spoke Saturday, December 5 at the 57th American Society of Hematology (ASH) Annual Meeting.
Most newly-diagnosed childhood cancers are acute lymphoblastic leukemias (ALL). But myeloid malignancies — those affecting the red blood cells — represent 20% of childhood leukemias, and these, along with Hodgkin and non-Hodgkin lymphomas, account for 15% of all malignancies diagnosed before age 14 years in the United States, said E. Anders Kolb, MD. He is director, Blood and Bone Marrow Transplant Program, Nemours Center for Cancer and Blood Disorders, Alfred I. duPont Hospital for Children in Wilmington, Del.
Myeloid malignancies and lymphomas are often referred to as the “other” childhood cancers, he said.
Despite advances, children diagnosed with acute myeloid leukemia (AML) suffer “a considerable survival gap,” Kolb noted. “As a result, these cases contribute significantly to childhood cancer mortality.”
In contrast, pediatric and adolescent Hodgkin lymphoma “is one of the most curable forms of childhood cancer,” noted Kara M. Kelly, MD, pediatric oncologist, Department of Pediatrics, Division of Pediatric Hematology/Oncology/Stem Cell Transplantation department, Columbia University Medical Center, in New York, N.Y. The challenge these patients face is that their long-term survival rates decline in adulthood because of long-term side effects like secondary cancers and cardiovascular disease, resulting from cancer treatment in childhood.
As a result of these chronic-disease-associated premature deaths among long-term survivors, Hodgkin Lymphoma has one of the highest societal burdens of cancer, in terms of lost productivity, Kelly noted. “This impacts not only the individual patient, but society as a whole,” she said.
In the era of precision medicine, however, Kolb and Kelly are hopeful that next-generation gene sequencing and biomarkers can help identify ways to address both challenges, improving survival rates and reducing toxicities for children with these “other” pediatric cancers.
“The major challenge is to optimize the balance between overall survival and treatment-related toxicity,” said Kelly. “Despite our good overall survival rates, there really is no standard of care or stratified-risk strategy for pediatric Hodgkin [Lymphoma].”
There is no consensus about chemotherapy or radiotherapy strategies, imaging standards are outdated and lacking evidence, and the underlying biology is “not yet advanced enough to guide treatment,” she lamented.