Clinical Outcomes of Elderly Patients with Advanced-Stage Classic Hodgkin Lymphoma Who Received an ABVD Regimen: A Multi-Center Retrospective Study in Japan (HORIZON study)

Introduction The prognosis of classic Hodgkin lymphoma (cHL) in young adults has improved following advances in current therapeutics. However, evidence of elderly patients with cHL has limited due to its rarer. To analyze clinical outcomes and risk factors in elderly patients with advanced-stage cHL who received a doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) regimen, we conducted a nationwide multi-center retrospective study in Japan (UMIN000033264). Methods The key eligibility criteria of the current study were as follows: 1) patients with histologically diagnosed cHL between 2007 and 2016 in each institution; 2) advanced-stage cHL (stage III, IV or IIB with bulky or extranodal lesion); 3) age at diagnosis > 60 years; and 4) had received at least one cycle of an ABVD regimen as initial treatment including a modified ABVD regimen (dacarbazine dose reduced to 250 mg/m 2 at first cycle). Patients with human immunodeficiency virus infection or methotrexate-associated cHL were excluded. The primary endpoint was 5-year overall survival (OS). Secondary endpoints included progression-free survival (PFS) and event-free survival (EFS), the latter defined as the time from a diagnosis of cHL to disease progression or relapse, subsequent systemic chemotherapy for cHL, or death due to any cause in this study. The average relative dose intensity (ARDI) of ABVD was calculated as the sum of the relative dose intensity of each drug divided by four. Results A total of 171 patients from 45 institutions were included in this study. The central pathological review could be performed in 140 cases (82%), in which histological subtypes of cHL were determined as follows: mixed cellularity, 89 (64%); nodular sclerosis, 33 (24%); lymphocyte-deleted, 4 (3%); lymphocyte-rich, 2 (1%); not otherwise specified, 12 (9%). The median age was 71 years (interquartile range [IQR] 65-76). The number of patients in each 10-year age group was 79 (46%) for 61-70 years, 78 (46%) for 71-80 years, and 14 (8%) for > 81 years. The numbers of patients with ECOG performance status (PS) ≥2 and B symptoms were 33 (19%) and 85 (50%), respectively. Bulky mediastinal diseases were found in four patients (2%). The risk factors used for the International Prognostic Score (IPS), including male sex, stage IV, hypoalbuminemia, anemia, leukocytosis, and lymphopenia, were not significantly different among these age groups. The median number of cycles of ABVD was 6 (IQR:5-7), and 66% of patients comple