PHILADELPHIA — Some Latino children diagnosed with acute lymphoblastic leukemia (ALL) were more likely to relapse than non-Hispanic white children, according to data presented at the 2022 AACR Annual Meeting, held April 8-13. The study found that in patients with no minimal residual disease (MRD), often considered a strong predictor of cure, relapse was more common in the Latino population.
ALL is the most common cancer in children. Thanks to advances in treatment, the five-year survival rate for children diagnosed with ALL is about 90 percent.
Nevertheless, about 15 percent of children with ALL will experience a relapse, explained the study’s lead author, Philip Lupo, PhD, professor of pediatrics at Baylor College of Medicine, director of the Epidemiology and Population Sciences Program at Texas Children’s Cancer and Hematology. Center, and a member of the Dan L Duncan Comprehensive Cancer Center at Baylor.
“Outcomes after a relapse are much worse, with only 35 percent of children surviving after a recurrence of the disease,” Lupo said. “In addition, poor outcomes are more common in Latinos, who are also more likely to develop ALL compared to non-Latino whites.”
Detection of MRD in the bone marrow after the first month of treatment is the strongest prognostic factor for ALL relapse. However, about half of all recurrences occur in children who are MRD negative. In this study, Lupo and colleagues sought to examine associations between MRD status and Latino ethnicity and characterize other factors associated with relapse.
The researchers examined data from the Consortium Reducing Ethnic Disparities in Acute Leukemia (REDIAL), which included patients diagnosed with ALL at six major pediatric cancer centers in the southwestern United States. The study included 1,620 children diagnosed with ALL between 2004 and 2018 with a median age at diagnosis of 5 years. The majority were Latino (60.1 percent) and male (56.9 percent).
A total of 382 (23.5 percent) of the subjects were MRD positive. Of these, 73 (19.1 percent) experienced a relapse, compared with 136 of 1,238 (11.0 percent) MRD-negative patients. Among the MRD-positive patients, Latinos were less likely to relapse compared to non-Latino whites. However, Latinos who were MRD negative were about 65 percent more likely to relapse than non-Latino whites. This finding suggests that MRD status may not be such a strong prognostic factor in predicting relapse risk in Latino children with ALL compared to non-Latino whites, according to Lupo.
Among other factors identified in the study, patients diagnosed with ALL after age 15 were nearly twice as likely to relapse as patients aged 1 to 5. Patients enrolled in a therapeutic clinical trial for ALL were less likely to relapse.
Lupo said the study highlights the importance of investigating the causes of health disparities in cancer.
“We were surprised that Latinos who were MRD negative were more likely to have ALL relapses compared to non-Latino whites,” he said. “This highlights the need to identify factors that contribute to relapse in Latinos so that we can achieve better outcomes for children of all racial and ethnic backgrounds.”
Lupo said that while MRD should still be considered an important prognostic factor in ALL, this study indicates it may not have the same prognostic implication for all populations.
The REDIAL consortium also continues to explore other ethnic differences in ALL and acute myeloid leukemia. They are investigating why Latinos are more likely to develop leukemia and are also investigating the frequency and risk factors that may increase the development of treatment-related toxicities.
Lupo noted that a limitation of the study is that the researchers did not have complete information on all factors that could have influenced relapse risk. He added that future research will incorporate other important factors into predictive models of ALL outcomes, including biological features inherent in the leukemia, heritable genetic factors and social determinants of health.
This study was funded by St. Baldrick’s Foundation and the National Cancer Institute. Lupo declares no conflict of interest.
COI statement
dr. Lupo declares no conflict of interest.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of any press releases posted on EurekAlert! by sponsoring institutions or for the use of information through the EurekAlert system.
Comments are closed.