Impact of risk-stratified therapy on health status in survivors of childhood Acute Lymphoblastic Leukemia: a report from the Childhood Cancer Survivor Study

BACKGROUND Prior studies have identified that survivors of childhood acute lymphoblastic leukemia (ALL) report poor health status. It is unknown how risk-stratified therapy impacts the health status of ALL survivors. METHODS We estimated and compared the prevalence of self-reported poor health status among adult (≥18 years) survivors of childhood ALL diagnosed at age <21 years from 1970 to 1999 and sibling controls, excluding proxy reports. Therapy combinations defined treatment groups representative of 1970s therapy (70s), standard- and high-risk 1980s and 1990s therapy (80sSR, 80sHR, 90sSR, 90sHR), and relapse/bone marrow transplant (R/BMT). Log-binomial models, adjusted for clinical and demographic factors, compared outcomes between groups using prevalence ratios (PR) with 95% confidence intervals (CI). RESULTS Among 5,119 survivors and 4,693 siblings, survivors were more likely to report poor health status in each domain including poor general health (13.5% vs. 7.4%; PR = 1.92; 95% CI, 1.69-2.19). Compared with 70s, 90sSR and 90sHR were less likely to report poor general health (90sSR: PR = 0.75; 95% CI, 0.57-0.98; 90sHR: PR = 0.58; 95% CI, 0.39-0.87), functional impairment (90sSR: PR = 0.56; 95% CI, 0.42-0.76; 90sHR: PR = 0.63; 95% CI, 0.42-0.95), and activity limitations (90sSR: 0.61; 95% CI, 0.45-0.83; 90sHR: PR = 0.59; 95% CI, 0.38-0.91). An added adjustment for chronic conditions in multivariable models partially attenuated 90sSR risk estimates. CONCLUSIONS Risk-stratified ALL therapy has succeeded in reducing risk for poor general health, functional impairment, and activity limitations among more recent survivors of standard- and high-risk therapy. IMPACT Future research into the relationship between risk-stratified therapy, health status, and late health outcomes may provide new opportunities to further improve late morbidity among survivors.