A New Simplified Prognostic Index Integrating the Type of Extra-Nodal Involvement and Age for Ann Arbor Stage IV Hodgkin Lymphoma Patients Diagnosed at TEP-Scanner Era: A Retrospective Analysis from Lymphoma Study Association (LYSA) Centers

Purpose International Prognostic Index (IPS) is the most widely used risk stratification index for advanced stage Hodgkin's lymphoma (HL). The use of (18F)-fluorodeoxyglucose PET/CT at diagnosis allows a better characterization of extra-nodal involvement (ENI). We investigated if the type of ENI could affect the prognosis of stage IV HL patients diagnosed with PET/CT and if a specific prognostic index could be defined for these patients (pts). Patients and methods We retrospectively analyzed 220 stage IV HL patients treated from 2005 to 2015 in three LYSA centers. We considered the local investigator interpretation based on the nuclear medicine physician PET/CT report. Regarding ENI, six subgroups were identified: involvement of lung and/or pericard and/or pleural, liver, diffuse and/or focal bone involvement, digestive system, and other involvements; we also considered bone marrow involvement based on the results of bone marrow biopsy. The main outcome was event free survival (EFS) defined by relapse, progression, death from any cause and initiation of a new therapy. For prognostication, we first evaluated the six variables of IPS-6 (corresponding to IPS without "stage IV" item) in this population. ENI was tested adjusted on the retained IPS variables. Univariate and multivariate Cox models were used to assess their prognostic ability for EFS. Cross-validation (10-fold) was used to select the more robust variables avoiding optimism. The finally selected variables constituted a score that was tested on overall survival (OS). Results Among the 220 stage IV patients, 135 (61%) were male. Median age was 33 years (range, 16-86) and 72 pts (33%) were ≥45 years. 130 pts (59%) presented constitutional symptoms. Nodular sclerosis subtype was observed in 163 pts (74%), mixed cellularity subtype in 25 pts (11%) and 47/157 pts (30%) presented EBV-positive HL. For biological parameters of IPS, 158 pts (80%) had low albumin level 15G/L in 42pts (19%) and lymphocyte count Conclusions: For stage IV HL defined by PET/CT, we developed a simple prognostic score based on age (≥45y) and liver involvement that identify a subgroup of patients with a poor outcome. These findings need to be validated in independent cohorts. Based on these results, whether HL pathogenesis differs by ENI sites should be investigated. Disclosures Bachy: Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda: Research Funding; Beigene: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Amgen: Honoraria. Karlin:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support. Sarkozy:ROCHE: Consultancy. Traverse-Glehen:Takeda: Research Funding; Astra Zeneca: Other: Travel. Salles:F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Servier: Honoraria, Other: Advisory Board; Novartis: Consultancy, Honoraria; BMS: Honoraria, Other: Advisory Board; Morphosys: Honoraria; Janssen: Honoraria, Other: Advisory Board; Abbvie: Honoraria; Pfizer: Honoraria; Amgen: Honoraria; Celgene: Honoraria, Other: Advisory Board, Research Funding; Epizyme: Honoraria; Gilead: Honoraria, Other: Advisory Board; Acerta: Honoraria; Merck: Honoraria; Servier: Honoraria; Takeda: Honoraria. Casasnovas:Takeda: Consultancy; Gilead: Consultancy, Research Funding; AbbVie: Consultancy; Roche: Consultancy, Research Funding; Bristol-Meyers Squibb: Consultancy; Merck: Consultancy. Ghesquieres:Celgene: Consultancy; Gilead: Consultancy; Sanofi: Consultancy.