Most adolescents, young adults with leukemia subtype treated with therapies meant for adults

ATLANTA — The number of adolescents and young adults with acute lymphoblastic leukemia treated with pediatric-inspired chemotherapy regimens appears to be quite low, according to results from the California Cancer Registry presented at the ASH Annual Meeting and Exposition.

Perspective from Amelia A. Langston, MD

“Abundant evidence suggests that [adolescents and young adults] with ALL have improved outcomes when treated following pediatric-inspired, as opposed to adult, ALL chemotherapy regimens,” the researchers wrote. “Given the complexity of pediatric ALL protocols, it is unclear whether this approach has been universally accepted by medical oncologists treating [adolescent and young adult patients with ALL] across the population.”

Lori S. Muffly, MD, clinical assistant professor of blood and marrow transplantation in the department of medicine at Stanford University, and colleagues used the population-based California Cancer Registry to examine characteristics of adolescents and young adults aged 15 to 39 years with newly diagnosed ALL who received treatment in California between 2004 and 2014. The researchers included sociodemographics, location of induction therapy (adult vs. pediatric setting) and treatment types in their analysis.

Among 1,591 adolescents and young adults with ALL, 61% received treatment in an adult oncology setting and 28% received treatment in a pediatric setting. The researchers could not identify the treatment setting for 11% of patients (n = 175); these individuals were omitted from further analyses.

More than one-third of patients (39%) were aged 19-29 years; 32% were aged 15-18 years and 29% were 30-39 years. The majority of patients (64%) were male and of Hispanic race/ethnicity (64%). Patients were more likely to have public vs. private insurance (46% vs. 44%).

Treatment in a pediatric setting appeared more common among patients who were younger (P < .001) and were diagnosed more recently (P = .03), as well as adolescents and young adults with public insurance (P = .01). Adolescents and young adults treated in pediatric settings were more likely than those treated in adult settings to undergo induction therapy at an NCI-designated cancer center (59% vs. 41%; P < .001). Patients treated in the adult setting also had a greater likelihood of receiving care at low-volume facilities — classified as a facility with less than one case of adolescent and young adult ALL per year — compared with those treated in the pediatric setting (27% vs. 5%; P < .001).

Most adolescents and young adults (79%; n = 1,131) had available data on ALL treatment regimens. Over the course of a decade, more than three-quarters of these patients (78%) received adult ALL treatment regimens; only 22% received pediatric-inspired regimens. Although medical oncologists appeared more likely to administer pediatric-inspired regimens over the course of the study, 62% of adolescents and young adults treated by these physicians between 2013 and 2014 received adult ALL regimens. Treatment with hyper-CVAD — which includes hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone — was the regimen used most frequently (70%).

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Multivariable regression demonstrated that younger age (19-24 years vs. 35-39 years; OR = 2.1; 95% CI, 1.4-3.2), treatment at an NCI-designated center (OR = 5.3; 95% CI, 2.5-11.3) and treatment at a higher-volume adolescent and young adult ALL facility [mid quartile vs. lowest quartile (OR, 2.3; 95% CI 1-5.2) and highest quartile vs. lowest quartile (OR, 7.4; 95% CI, 2.7-20.4)] correlated with receiving pediatric-inspired ALL regimens administered by medical oncologists. Researchers observed no such association between year of diagnosis, sex, race/ethnicity and type of insurance.

The population-level findings from this study indicate that adolescents and young adults with ALL in California “are most commonly treated in adult oncology community settings, where the volume of [adolescent and young adult patients with ALL] seen on a yearly basis is frequently very low,” the researchers wrote.

“Strikingly, as recently as 2014, [adolescents and young adults] with ALL continue to be treated predominantly with adult ALL regimens,” they continued. “Receipt of pediatric-inspired ALL regimens is significantly more likely if [adolescents and young adults] with ALL receive treatment at NCI-designated cancer centers and/or centers that treat a higher yearly volume of [adolescent and young adult patients with ALL].” – by Julia Ernst, MS

Reference:

Muffly LS, et al. Abstract 611. Presented at: ASH Annual Meeting and Exposition; Dec. 9-12, 2017; Atlanta.

Disclosures: The researchers report no relevant financial disclosures.

Perspective

Amelia A. Langston, MD

There are a number of studies demonstrating that adolescents and young adults with ALL have improved outcomes if they are treated with pediatric-like treatment regimens. These pediatric-like regimens are aggressive, complicated and very different than the treatment regimens we typically use in adults.

This study examined whether patients in the California Cancer Registry aged 15 to 39 years with ALL diagnoses received adult-like regimens or pediatric-like regimens.

The answer was quite striking. Only about 20% of patients in this registry received pediatric regimens, despite the fact that we have abundant data demonstrating patients do better when treated with more aggressive pediatric regimens. Most patients were treated at adult centers with regimens typically used for adults. Patients appeared more likely to be treated with pediatric regimens at large centers, NCI-designated cancer centers and centers that treat many adolescents and young adults.

The issue is that these pediatric regimens are much more complex and much less iterative. Pediatricians are very comfortable using those regimens, but that’s not so true for adult oncologists. It takes much more effort for an adult oncologist to treat patients with these more aggressive, more complicated regimens. I think adolescents and young adults are more likely to receive that treatment at a big center that does it all the time than at a small center that sees very few patients with ALL.

The results point to the need to refer adolescents and young adults with ALL to large centers, where there is more familiarity with these regimens that are more aggressive and more complex.

Amelia A. Langston, MD

Professor and Executive Vice Chair, Department of Hematology and Medical Oncology (Emory University School of Medicine)

Medical Director and Section Chief, Bone Marrow and Stem Cell Transplant Program (Winship Cancer Institute of Emory University)

Medical Director, Winship Cancer Network (Winship Cancer Institute of Emory University)

Disclosures: Langston reports research funding through her institution from Kite Pharmaceuticals and Novartis.