Introduction: The optimal therapeutic approach for AYAs with HL remains unclear. We examined AYAs treated on 2 recent, randomized pediatric and adult North American HL studies.
Methods: The characteristics, failure free survival (FFS) and overall survival (OS) of 114 AYA HL patients (pts) [17-21 years(yr)] treated on E2496 (ABVD vs. Stanford V [SV], Gordon JCO 2013) were compared with pts >21 years on E2496. The characteristics, FFS and OS of these ECOG AYAs were compared with 391 AYAs (17-21 yr) treated on COG AHOD0031 (ABVE-PC backbone, Friedman JCO 2014). Stratified log-rank tests and propensity score analysis were utilized to compare outcome differences.
Results: In E2496, the 5-year FFS and OS rates for AYAs were 68% and 89%, respectively, with significant variations identified by pt age (Table). There was no FFS difference between ECOG AYAs treated with ABVD vs. SV (P=0.66). FFS in AYAs were inferior to those ages 21 to 44 yr (P =0.005) but appeared more similar to patients aged 45-59 yr. There was no significant difference in sex, race, or histology in COG or E2496 AYAs. Due in part to trial design differences, a larger proportion of E2496 AYAs were stage III or IV vs. COG AYAs (63% vs. 29%, P<0.001) and had B symptoms (63% vs. 27%, P<0.001); fewer E2496 pts had bulk disease (33% vs. 77%, P<0.001). There was no significant difference in extralymphatic disease, anemia or low albumin. More COG AYAs received radiotherapy (76% vs. 66%, P=0.03), though in smaller doses (21 Gy vs 36 Gy). The 5-year FFS and OS for COG AYAs were 80% and 97%, respectively. COG AYAs appeared to have superior FFS compared with E2496 AYAs (P=0.001). In multivariable analyses (controlled for stage, anemia, bulk), E2496 AYAs appeared to have worse FFS compared with COG AYAs in all strata except among those with stage I/II without anemia. Propensity score analysis matched on stage, anemia, and bulk disease confirmed inferior FFS for E2496 compared with COG AYAs (P=0.004). The AYA survival disparity across studies persisted after additional covariates were incorporated into the propensity score (ie, age, gender, B symptoms and hypoalbuminemia; P=0.026).
Conclusions: AYA HL pts treated on E2496 had inferior outcomes compared with older pts (22-44 yr) on same study, and to similarly matched AYA pts treated on COG AHOD0031. This may reflect differing treatment regimens, risk profiles, biology, or other factors. Prospective examination of these issues in AYA HL pts is warranted.
This abstract has been presented as Abstract Talk in “Pediatric HL”
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