Purpose: To evaluate the CHIPS (Childhood Hodgkin International Prognostic score) in patients with intermediate risk (IR) Hodgkin Lymphoma (HL) randomized to +/- 21 Gy of involved filed radiation (IFRT) after completing 4 cycles of ABVE-PC. These patients had achieved a rapid early response (RER) to 2 cycles of ABVE-PC (RER) and complete response (CR) at the end of chemotherapy.
Methods: Patients enrolled on COG AHOD were <21 years with IR HL. The CHIPS score was derived from clinical data on 1103 patients who had received 4 ABVE-PC and radiation. Four factors (fever, low albumin, large mediastinal adenopathy, stage 4) were identified as independent predictors of EFS. CHIPS was then examined in the cohort of RER who achieved CR and were randomized to receive or not receive IFRT.
Results: There were 664 RER/CR patients with CHIPS scores available; 329 were randomized to no RT and 335 were randomized to RT. 4 year EFS was similar between CHIPS cohorts except for CHIPS 1. CHIPS 1 patients showed an advantage to the addition of IFRT (p=0.035). CHIPS 0 patients did well with or without IFRT. CHIPS 3 patients had poor outcomes with or without RT.
Conclusion: CHIPS was derived based on patients treated on COG protocol AHOD0031 who received IFRT after ABVE-PC chemotherapy. For this report, we compared CHIPS in the RER/CR cohort randomized to IFRT vs. no IFRT. Although the overall randomization to +/- RT (Friedman, JCO 2015) did not detect any advantage to the addition of IFRT, this sub-analysis shows that 1) CHIPS was predictive of outcome in both the radiated and the un-irradiated cohort and 2) there may be a benefit for IFRT in the CHIPS 1 cohort. As in the overall cohort, CHIPS 2 and 3 patients should be considered for augmented therapy.