Lymphocyte-Predominant Hodgkin Lymphoma Variant: Long Term Outcome. Data From The Lh-2004 Protocol Of The Italian Association Of Pediatric Hematology And Oncology (Aieop)

Introduction Lymphocyte-predominant Hodgkin lymphoma (LPHL) is a distinct lymphoid malignancy accounting for approximately 5% of all patients with HL. The clinical course is usually indolent, and most patients are diagnosed with early-stage disease. Because of the rare nature of the disease, few large-scale studies are available.

Aim of the study to evaluate the long term outcome of patients with LPHL enrolled in the AIEOP-LH 2004 protocol that represents the 4th Italian protocol for the pediatric HL therapy.

Methods This is a retrospective study. Patients were stratified in 3 risk groups: low risk G1 (stage I-IIA without: M/T ≥0.33 or ≥4 nodal sites or hilar adenopathy), intermediate risk G2 (patients not included in G1 and G3) and high risk group G3 (stages IIIB-IV and patients with M/T ≥0.33). GR1: 3 ABVD+25,2 Gy only to PR after CT. GR2: 4 COPP/ABV+14,4 Gy if CR achieved; PR pts received 2 cycles of IEP (Ifosfamide, Etoposide and Prednisone) and RT (14,4 Gy if CR, 25,2 if PR). GR3: 4 COPP/ABV and 2 further COPP/ABV+RT if CR was achieved. PR pts: 2 IEP+14,4 Gy if CR was obtained; if not, pts received 2 additional COPP/ABV+RT according to the quality of response.

Results From June 2004 to June 2017, 89 patients with LPHD were enrolled into the protocol, 61 in G1, 19 in G2 and 9 in G3. The stratification according to stage is: 23 pts stage I (no pts with B symptoms), 47 stage II (46 IIA, 1 IIB), 17 stage III (14 IIIA, 3 IIIB), 2 stage IV (1 IVA, 1 IVB). Patients were mostly male (83,5%). The median age at diagnosis was 11,9 years. The median observation time of follow up was 8,41 years. Mediastinal involvement occurred in 12/47 stage II pts, in 6/17 stage III and in 2/2 stage IV. Bulky disease was observed in 3 pts, all in stage II. Radiotherapy was performed in 41/61 pts of G1 patients. 11 relapses and 3 progressions of disease were registered; no case of second malignancy or death occurred. 8 pts were lost to follow-up. Median time to relapse was 3,06 years. The Event-Free Survival at 10 years of LPHL patients is 83,1% versus 78,25% of classical HL patients (p=ns).

Conclusion LPHL behaves as a distinct clinical entity, often in low stage without risk factors, with a good outcome, better than classical HL. For these reasons LPHL requires its own treatment approach, guided by various clinical and pathological factors, to optimize the management and improving their outcome.