Interim PET-guided treatment for early-stage NLPHL: a subgroup analysis of the randomized GHSG HD16 and HD17 studies.

The optimal first-line treatment for nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) diagnosed in early stages is largely undefined. We, therefore, analyzed 100 NLPHL patients treated in the randomized HD16 (early-stage favorable; n = 85) and HD17 (early-stage unfavorable; n = 15) studies. These studies investigated the omission of consolidation radiotherapy (RT) in patients with a negative interim positron emission tomography (iPET) (ie, Deauville score <3) after chemotherapy (HD16: 2× doxorubicin, bleomycin, vinblastine, and dacarbazine [ABVD]; HD17: 2× escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone [BEACOPP] plus 2× ABVD). Patients with NLPHL treated in the HD16 and HD17 studies had 5-year progression-free survival (PFS) rates of 90.3% and 92.9%, respectively. Thus, the 5-year PFS did not differ significantly from that of patients with classical Hodgkin lymphoma treated within the same studies (HD16: P = .88; HD17: P = .50). Patients with early-stage favorable NLPHL who had a negative iPET after 2× ABVD and did not undergo consolidation RT tended to have a worse 5-year PFS than patients with a negative iPET who received consolidation RT (83% vs 100%; P = .05). There were 10 cases of NLPHL recurrence. However, no NLPHL patient died during follow-up. Hence, the 5-year overall survival rate was 100%. Taken together, contemporary Hodgkin lymphoma-directed treatment approaches result in excellent outcomes for patients with newly diagnosed early-stage NLPHL and, thus, represent valid treatment options. In early-stage favorable NLPHL, consolidation RT appears necessary after 2× ABVD to achieve the optimal disease control irrespective of the iPET result.