Study Shows Survival Advantage for Certain Leukemia Patients Treated in Pediatric Cancer Centers

By Thomas Crocker
Saturday, September 1, 2018
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Adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) have better survival rates if treated in pediatric cancer centers versus adult centers, according to a recent study in Blood Advances.

Only 5,960 new cases of ALL are expected in 2018, according to the American Cancer Society. However, the condition is a staple of practice for pediatric oncologists, as it is most likely to develop during childhood.

For about a decade, researchers have known that AYAs — patients age 15–39 — fare better when treated with pediatric protocols, according to Lori Muffly, MD, MS, Clinical Assistant Professor of Medicine–Blood and Marrow Transplantation at Stanford University. Recently, Dr. Muffly and other researchers conducted a population-based study to assess the impact of care setting (pediatric versus adult cancer center) on outcomes in AYAs with ALL. The study is one of the first to explore that issue, according to Elysia Alvarez, MD, MPH, Assistant Professor of Clinical Pediatrics at the University of California, Davis. It builds on a 2017 pilot study by a number of the same researchers that involved data from a regional cancer registry.

Comparing Care Settings

For the more recent study, researchers used a statewide database, the California Cancer Registry, to find 1,795 cases of ALL diagnosed in AYAs from 2004 to 2014; they included 1,473 in their analysis. To determine each patient’s treatment regimen, the group looked at facility-level data supplied to the state registry by regional registries.

“[W]e took the really innovative approach of going into the text fields in the cancer registry ... to abstract treatment information to get at [patients’] initial regimens,” says Theresa Keegan, PhD, MS, Associate Professor in the Division of Hematology and Oncology at the UC Davis Comprehensive Cancer Center and a co-author of the study. “This is not something that’s commonly available in the cancer registry. We were able to show from our [2017 pilot study] and now this statewide work that we could capture this data and determine pediatric versus adult setting.”

Two-thirds of the patients in the study received treatment in an adult cancer center, and of that number, only 33 percent received pediatric regimens in those facilities. Nearly 87 percent of younger AYAs — patients age 15–18 — were treated in a pediatric setting. However, only 16 percent of 19- to 24-year-old patients received care in pediatric cancer centers, and more than 98 percent of 25- to 39-year-old patients were treated in adult cancer centers.

Patients treated in pediatric settings as well as those treated in National Cancer Institute (NCI)-designated Comprehensive Cancer Centers or Children’s Oncology Group (COG) centers enjoyed sizable advantages in overall survivability, with hazard ratios of 0.53 for pediatric settings and 0.80 for the latter two settings. The data showed a positive trend that may indicate greater recognition in the medical community of the importance of referring AYAs to pediatric cancer centers: The percentage of AYAs who received care in such centers increased by more than seven points during the study period.

What Sets Pediatric Centers Apart?

To the study’s authors, pediatric cancer centers’ expertise is key.

“[ALL] is the bread and butter of pediatric oncologists,” says Dr. Muffly, lead author. “Would you rather go to a surgeon who performs two heart transplants a year or 150?”

“There’s a standard of care given at [pediatric cancer centers] that’s elevated compared to other centers,” Dr. Alvarez says. “[T]here’s more ability to administer chemotherapy per the protocol, enroll patients on [new] protocols, and have social services and things like that, that AYAs might need.”

The findings echo those of a 2017 study by a group that included Julie Wolfson, MD, MSHS, Assistant Professor of Pediatrics and a member of the Institute for Cancer Outcomes and Survivorship at the University of Alabama at Birmingham. Using data from Los Angeles County, California, that group found that 15- to 29-year-old ALL patients treated in specialized cancer centers enjoyed much higher survival rates than peers who did not visit such centers. The reasons for that advantage are likely multifactorial and include supportive care, a multidisciplinary approach to care, clinical trial enrollment and the dual presence of clinical work and research, according to Dr. Wolfson, who treats patients at Children’s of Alabama.

She says compliance is likely a key factor in the advantage patients in the pediatric model hold.

“The internal medicine model is very individualistic, [whereas] the pediatric model is more of a paternalistic model where the system will not let you fall off,” Dr. Wolfson says. “From many different angles, the system is reminding you, supporting you and helping you to stay on time. Adherence on the patient’s part to staying on schedule is probably enhanced ... in a pediatric model due to the differences in the ways we operate.”

Dr. Muffly says referring clinicians must carefully assess which care setting will give their patients the best opportunity to do well. ALL is extremely rare in adults and potentially curable, she says, but management of the disease is evolving rapidly.

“When you see a patient with ALL, strong consideration should be [given to] where they would receive the most up-to-date, comprehensive care in 2018,” Dr. Muffly says.