Abstract P136

The prognostic value of ΔSUVmax and TARC in the first-line treatment of classical Hodgkin lymphoma

Background: In classical Hodgkin lymphoma (cHL), early risk stratification and response assessment are the cornerstones of therapy. The advanced interpretation of positron emission tomography / computed tomography (PET/CT) results and the inclusion of other biomarkers may provide a unique approach to the response assessment in cHL.

Aim: Our aim was to investigate the prognostic value of the change in standardized uptake value (∆SUVmax) and thymus and activation-regulated chemokine (TARC) to predict disease progression during the first-line treatment of cHL.

Methods: We retrospectively analysed adult patients with cHL, treated with a curative intent, standard therapy. The analysed PET/CT assessments were performed at baseline and after 2 cycles of first-line therapy. ∆SUVmax was calculated with the following formula: (baseline SUVmax – interim SUVmax)/baseline SUVmax × 100. TARC levels were measured by an immunoassay. Cut-off values were determined by the receiver operating characteristics (ROC) analysis. Survival analysis was performed by the Kaplan-Meier method via the log-rank test.

Results: Altogether, 81 patients had sufficient data for analysis. The presence of a ∆SUVmax of >80%, and a TARC level of ≤850 pg/mL after 2 cycles of therapy were independent prognostic factors for longer progression-free survival (PFS) (p=0.045 and p=0.017, respectively). The PFS of patients without any of these two risk factors differed from the patients positive for one or both parameters (p=0.03). According to the German Hodgkin Study Group’s (GSHG) risk group classification system, patients with an advanced stage cHL had a better PFS if none of the risk factors were present (p=0.019). There was no difference in PFS between patients with a Deauville Score (DS) of 1-2, with the presence of any of the risk factors, and patients with DS 3. This group of patients experienced an inferior PFS compared to DS 1-2 patients without any risk factors (p=0.04) and a superior PFS versus patients with a DS of 4-5 (p=0.003).

Conclusion: Interim PET/CT response should be discussed in the light of ∆SUVmax and TARC values. Determining patient populations at elevated risk of shorter PFS should be addressed adequately in everyday practice. Our results can draw attention to patients requiring more rigorous monitoring.