A study of nearly 25,000 young people with ALL reveals significant gaps in survival rates between white, Hispanic, and Black patients, as well as worse outcomes among those of lower socioeconomic status. Biological or genetic factors accounted for some, but not all, of the disparity.

“Our study shows that race and ethnicity-based disparities continue to exist and are substantial,” said Sumit Gupta, MD, of The Hospital for Sick Children in Toronto, Canada.

“All groups do well overall, but some do substantially better than others.

There is an urgent need to examine the factors leading to these different outcomes among different racial and ethnic groups.”

The researchers analysed health records of 24,979 patients diagnosed with ALL at age 30 or younger who enrolled in clinical trials of the Children’s Oncology Group – a large network of paediatric oncology centres and clinical trials across North America, Australia, and New Zealand – between 2004 and 2019.

White patients on average had a five-year event-free survival rate of 87.4%, compared with 82.8% for Hispanic patients and 81.9% for Black patients.

In the U.S., patients on Medicaid, an indicator of low socioeconomic status, had a five-year event-free survival rate of 83.2% compared with 86.3% among U.S. patients not on Medicaid.

The analysis showed similar patterns for overall survival rates, although the magnitude of the disparities in overall survival was higher.

While some genetic mutations in leukaemia cells differed between racial and ethnic groups, they did not fully account for the observed differences in survival. “Based on the data, it is unlikely that leukaemia biology fully explains these disparities,” said Dr. Gupta. Differences in socioeconomic status among racial groups also do not fully explain the racial disparities, he noted.

Dr. Gupta said research to determine the specific reasons for these disparities is needed, particularly looking at the role of differences in access to health care, in treatments offered, or in the types of support children and families receive during cancer treatment.

Since the study focused on young people who were enrolled in clinical trials, which implies a certain level of access to care, he said the racial disparities observed in the study may be even more pronounced in the general population.

Source: ASH