In an analysis from the Childhood Cancer Survivor Study reported in the Journal of Clinical Oncology, Dixon et al found that 5-year survivors of childhood acute lymphoblastic leukemia (ALL) diagnosed and treated with risk-stratified therapy in the 1990s had reduced morbidity and health-related late mortality compared with those treated in the 1970s. The researchers found those treated in the 1990s had health-related late mortality and second malignant neoplasm risks comparable to the general population.
Study Details
The study involved data from 6,148 survivors of childhood ALL (median age = 27.9 years, range = 5.9–61.9 years) diagnosed between 1970 and 1999. Outcomes were assessed according to groups defined by therapy combinations and treatment intensity, including 1970s-like treatment (70s), standard (SR)- or high-risk (HR) 1980s-like treatment (80sSR, 80sHR), and SR or HR 1990s-like treatment (90sSR, 90sHR).
“Risk-stratified therapy has reduced late morbidity and mortality among contemporary survivors of standard-risk ALL, represented by 90sSR. Health-related late mortality and second malignant neoplasm risks among 5-year survivors of contemporary, standard-risk childhood ALL are comparable to the general population.”— Dixon et al
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Key Findings
Overall, 20-year all-cause late mortality was 6.6%.
Health-related late mortality was similar among the 70s group (2.4%), 80sSR group (2.5%), and 80sHR group (3.2%). Compared with the 70s group, health-related late mortality was significantly reduced in the 90sSR group (0.3%, rate ratio = 0.2, 95% confidence interval [CI] =0.1–0.4) and in the 90sHR group (0.6%, rate ratio = 0.3, 95% CI = 0.1–0.7).
Compared with age-, sex-, race-, and year-matched U.S. population incidence rates from the Surveillance, Epidemiology, and End Results program, health-related late mortality was comparable in both the 90sSR group (standardized mortality ratio = 1.3, 95% CI = 0.8–2.0) and the 90sHR group (standardized mortality ratio = 1.7, 95% CI = 0.7–3.5).
Compared with the 70s group, only the 90sSR group had a reduced cumulative incidence of second malignant neoplasms (3.4% vs 0.7%; rate ratio = 0.3, 95% CI = 0.1–0.6). The incidence in the 90sHR group was 2.1%. The incidence in the 90sSR group did not differ from that in the U.S. population (standardized incidence ratio = 1.0, 95% CI = 0.6–1.6).
The 90sSR group had a reduced risk of severe chronic health conditions vs the 70s group (20-year cumulative incidence = 11.0% vs 22.5%) and lower risk for impaired memory (prevalence ratio = 0.7, 95% CI = 0.6–0.9) and impaired task efficiency (prevalence ratio = 0.5, 95% CI = 0.4–0.7).
The investigators concluded, “Risk-stratified therapy has reduced late morbidity and mortality among contemporary survivors of standard-risk ALL, represented by 90sSR. Health-related late mortality and second malignant neoplasm risks among 5-year survivors of contemporary, standard-risk childhood ALL are comparable to the general population.”
Stephanie B. Dixon, MD, MPH, of St. Jude Children’s Research Hospital, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by grants from the National Cancer Institute and American Lebanese Syrian Associated Charities. For full disclosures of the study authors, visit ascopubs.org.
