Prognostic Factors and Treatment Outcome in Lymphocyte Predominant and Classical Hodgkin’s Lymphoma: A Comprehensive Analysis of the German Hodgkin Study Group.

Introduction: Lymphocyte predominant Hodgkin lymphoma (LPHL) differs in histological and clinical presentation from classical Hodgkin lymphoma (cHL). Treatment of LPHL patients using standard approaches leads to complete remission (CR) in more than 95% of patients. However, differences in terms of relapse rates, overall survival (OS) and freedom from treatment failure (FFTF) between LPHL and cHL patients were suggested by a recent intergroup analysis. To obtain a more comprehensive picture, we reviewed all LPHL-cases registered in the GHSG database comparing patient characteristics and treatment outcome with cHL patients.

Patients and methods: We retrospectively analyzed 8298 HL patients treated within the GHSG trials (HD4 to HD12). 394 patients had LPHL and 7904 cHL. From 394 LPHL patients, 63% were in early favorable stage, 16% in early unfavorable and 21% in advanced stage of disease. Of the 7904 cHL patients analyzed, 22% were in early favorable, 39% in early unfavorable and 39% in advanced stages. 9% of LPHL patients had B symptoms compared to 40% in cHL patients.

Results: 91% LPHL vs. 86% cHL patients in early favorable stages, 86% vs. 83% in early unfavorable and 79% vs. 75% in advanced stages reached CR/CRu. 0.3% LPHL patients developed progressive disease (PD) compared to 3.7% cHL patients. The relapse rate of LPHL patients was very similar to cHL (8.1% vs. 7.9%). There were 2.5% secondary malignancies in LPHL and 3.7% in cHL patients. 4.3% LPHL patients and 8.8% cHL patients died. The FFTF rates for LPHL and cHL patients at a median observation of 41 or 48 months were 88% and 82% (p=0.0093), respectively. The OS for LPHL and cHL patients was 96% and 92%, respectively (p=0.0166). The analysis between LPHL stages showed significant differences in FFTF (p=0.0239). According to a multiple Cox-regression analysis, advanced stage (p=0.0089) and lymphocytes < 8% of white cell count was shown as negative prognostic factors for FFTF and age ≥ 45 years (p=0.008) as negative factor for OS in LPHL patients. Hb value < 10.5 g/dl was shown as negative factor for both, FFTF and OS (p=0.0125, p=0.0002).

Conclusion: This is the largest analysis comparing LPHL and cHL patients. We found differences in FFTF and OS rates between both groups and differences in FFTF between LPHL stages. New treatment protocols for LPHL patients with reduced intensity schedules are to be discussed.