Background: Classical Hodgkin Lymphoma (cHL) is considered highly treatable, but early identification of patients at risk of relapse after initial treatment remains challenging. Disease progression may involve innate features not captured by current prognostic criteria, which can be uncovered through comprehensive molecular analysis. We conducted deep gene expression analysis to identify molecular markers predictive of relapse in cHL patients.
Patients and Methods: We retrospectively reviewed local clinical records to include patients with confirmed cHL diagnosed between 2004 and 2019, aged 18-65, at any disease stage, and treated with systemic chemotherapy (e.g., ABVD or like regimens including BV-AVD). Baseline diagnostic biopsies underwent gene expression analysis using nCounter Nanostring Technology with the PanCancer Immune profiling panel. Genomic data were correlated with clinical, laboratory, and radiomic data, focusing on Progression-Free Survival (PFS) as the primary outcome. Immunohistochemistry was used for validation purposes.
Results: We identified 185 cHL patients, with available FFPE material for 155 cases. Among them, 32% were over 45 years old, 46% had stage III-IV disease, and 10% had Bulky disease. After a median follow-up of 67 months (range, 6–171 months), 31 PFS events were observed, resulting in a 4-year PFS rate of 80.4% (95%CI 74.1–87.3). Using Cox Proportional Hazard modeling, we identified 66 genes significantly associated with PFS (p<0.05). Among these, 41 genes were positively linked to improved PFS, suggesting a protective role and 25 genes were associated with reduced survival probability. Correlation analysis and gene ontology revealed a 7-gene signature related to B-cell pathways. Unsupervised clustering based on this signature identified two distinct patient clusters (Figure 1A). The low B-cell cluster (C0) had higher clinical event rates (p=0.03) and lower PFS rates compared to high B-cell clusters (p=0.007) (Figure 1B). Additionally, high PAX5 expression (a pivotal B-cell regulator) correlated significantly with better PFS (4-year PFS of 90%, 95%CI 82.7-97.3) compared to lower expression levels (4-year PFS: 71%, 95%CI 61.3-82.4) (Figure 1C). Evaluation of PAX5 immune staining in the tumor microenvironment supported its potential prognostic role.
Conclusion: These results suggest gene expression analysis could aid in early relapse detection and underscore the immune-modulatory role of B-cells in cHL progression.
Benedetta Donati, Tanja Lazic, Maria Elena Nizzoli, Alberto Bavieri, Rexhep Durmo, Riccardo Valli, Attilio Gennaro, Cristian Ascione, Alessia Ruffini, Stefano Pozzi, Annibale Versari, Francesco Merli, Alessia Ciarrocchi, Stefano Luminari