Impact of Risk-Based therapy on late morbidity and mortality in neuroblastoma survivors: a report from the childhood cancer survivor study.

BACKGROUND: Early efforts at risk-adapted therapy for neuroblastoma are predicted to result in differential late effects; the magnitude of these differences have not been well-described.

METHODS: Late mortality, subsequent malignant neoplasms (SMN), and severe/life-threatening chronic health conditions (CHCs), graded according to CTCAE v4.03, were assessed among 5-year CCSS survivors of neuroblastoma diagnosed 1987-1999. Using age, stage at diagnosis, and treatment, survivors were classified into risk groups (low [n = 425]; intermediate [n = 252]; high [n = 245]). Standardized mortality ratios (SMR) and standardized incidence ratios (SIR) of SMNs were compared to matched population controls. Cox regression models estimated hazard ratios (HR) and 95% confidence intervals (CI) for CHC compared to 1,029 CCSS siblings.

RESULTS: Among survivors (49.8% male; median age 21 years, range 7-42; median follow-up 19.3 years, range 5-29.9), 80% with low-risk disease were treated with surgery alone, while 79.1% with high-risk disease received surgery, radiation, chemotherapy ± autologous stem cell transplant (ASCT). All-cause mortality was elevated across risk groups (SMRhigh=27.7 [21.4-35.8]; SMRintermediate=3.3 [1.7-6.5]; SMRlow=2.8 [1.7-4.8]). SMN risk was increased among high- and intermediate-risk survivors (SIRhigh=28.0 [18.5-42.3]; SIRintermediate=3.7 [1.2-11.3]), but did not differ from the US population for survivors of low-risk disease. Compared to siblings, survivors had an increased risk of grade 3-5 CHCs, particularly among those with high-risk disease (HRhigh=16.1 [11.2-23.2]; HRintermediate=6.3 [3.8-10.5]; HRlow=1.8 [1.1-3.1]).

CONCLUSION: Survivors of high-risk disease treated in the early days of risk stratification carry a markedly elevated burden of late recurrence, SMN, and organ-related multi-morbidity, while survivors of low/intermediate-risk disease have a modest risk of late adverse outcomes.