Clinicians and researchers hope to improve care for more patients by building on success in treating children and extending new beneficial therapies to different leukemia subtypes
 
 
31 August 2023, CLEVELAND:  Leukemia treatment outcomes have improved significantly over the past decade, particularly in the case of acute lymphocyte leukemia, and especially in the pediatric population. Now, researchers and doctors are hoping to expand the treatment success rate across all age groups and all leukemia subtypes, says an expert from global health system Cleveland Clinic ahead of World Leukemia Day on September 4.
 
Leukemia is a group of cancers characterized by rapid, uncontrolled growth of abnormal blood cells called leukemia cells. It can occur in both children and adults and according to the World Cancer Research Fund International, it is the 13th most prevalent cancer globally.
 
In patients with leukemia, age has a considerable impact on outcomes and treatment approaches, says oncologist John C. Molina, MD, EdM, who is trained in Pediatric Hematology/Oncology and Adult Hematology and works with adolescent and adult patients at Cleveland Clinic’s Leukemia & Myeloid Disorders Division. 
 
Dr. Molina points out that in recent years the greatest treatment success rates have been seen in children aged one to nine who have acute lymphoblastic leukemia (ALL), with nine out of 10 cured if they have favorable-risk ALL that is more chemotherapy-sensitive.. Explaining the successes, he says, “Childhood leukemias tend to have a more favorable biology and children are mostly diagnosed with a more favorable-risk subtype of leukemia. In addition, children’s higher tolerance level for chemotherapy, and the fact that so many children are enrolled in clinical studies, contribute to better outcomes.”
 
Perspectives are shifting, however, says Dr. Molina, and more intensive, pediatric-inspired treatment regimens with better outcomes are increasingly being administered to older patients. “Currently, this includes patients aged up to 40, but this will likely be extended even further due to improvements in supportive care that can help older patients better tolerate the treatment,” he says. 
 
Other factors related to age that Dr. Molina and colleagues consider when creating treatment plans are the psychosocial and health needs unique to patients’ stages of life, for example, the need for fertility preservation and the availability of a support network.
 
Outlook and new therapies
Treatment outcomes for leukemia depend on which of the four main subtypes is diagnosed, says Dr. Molina. Leukemia is classified as ‘acute’ or ‘chronic’ based on how mature the leukemia cells are, and as ‘myeloid’ or ‘lymphocytic’ depending on which cell lineage the leukemia cells arise from in the bone marrow. 
 
Generally, says Dr. Molina, people diagnosed with chronic myeloid (CML) and chronic lymphocytic leukemias (CLL) can live a normal life and the outlook is positive with currently available treatments. On the other hand, acute myeloid (AML) and acute lymphocytic leukemia (ALL) are more aggressive subtypes and develop more rapidly, but the treatment options are quickly advancing and the outlook for patients is improving. 
 
Of the two acute leukemias, ALL is the more commonly diagnosed type among children and young adults, while AML is more associated with ageing. However, this does not mean that ALL is a pediatric disease, or that AML does not exist in the pediatric populations, Dr. Molina says. “ALL spans the age spectrum, peaking in early childhood and again around the age of 50, and about half of all cases occur in people over the age of 20. Similarly, although rare, children can be diagnosed with AML.”
 
Commenting on the development of new treatments, Dr. Molina points out that advances in treating a specific subtype or age group can often benefit other subtypes or age groups as well. He gives the example of recently FDA-approved CAR T-cell therapies in ALL. This therapy sees the extraction of a patients’ own T cells – a type of white blood cell that forms part of the immune system – which are modified to recognize and destroy cancer cells, before being multiplied and infused back into the patient’s bloodstream. “CAR T-Cell therapy began in the pediatric space and is now being used for adults with ALL. In addition, institutions such as Cleveland Clinic are investigating how its success in ALL can be translated to AML, which has a different biology and more heterogeneous cancer cells,” he says. 
 
According to Dr. Molina, development of immunotherapies such as CAR T-cell is important as they can improve outcomes while potentially reducing or even replacing chemotherapy exposure and its long-term consequences for patients. “Upcoming trials at Cleveland Clinic and other institutions will investigate how these therapies can be integrated into treatment plans earlier, and whether they could ultimately replace chemotherapy and bone marrow transplants as part of the curative approach,” he says.
 
“This is an exciting time in the field of leukemia, and we are cautiously optimistic about these ongoing trials, which we aim to make as accessible and inclusive as possible,” Dr. Molina concludes.