PB1788 B‐SYMPTOMS, PERFORMANCE STATUS, AND RESPONSE TO FIRST THERAPY AS SURVIVAL PREDICTIVE FACTORS FOR PERIPHERAL T‐CELL LYMPHOMA AT PROGRESSION/RELAPSE: A SINGLE INSTITUTE ANALYSIS

Background: Peripheral T‐cell lymphoma (PTCL) is a heterogeneous group of aggressive lymphomas that account for 5‐15% of non‐Hodgkin lymphomas. PTCL, not otherwise specified (PTCL‐NOS), is the most common subtype that accounts for 25.9% of PTCL, followed by angioimmunoblastic T‐cell lymphoma (AITL), NK/T‐cell lymphoma (NKTCL), Adult T‐cell Leukemia/Lymphoma (ATLL), ALK‐positive anaplastic large cell lymphoma (ALK+ ALCL), and ALK‐negative ALCL (ALK‐ ALCL) (Vose J. et al., 2008). The Prognostic Index for PTCL‐NOS (PIT; Gallamini A. et al., 2004) is a prognostic model widely used for PTCL‐NOS. There are, however, no established risk factors developed specifically for PTCL after progression/relapse. Aims: We analyzed the survival outcomes of PTCL after first progression/relapse, and report on newly identified prognostic factors for relapsed/refractory PTCL. Methods: We identified 144 patients with newly diagnosed PTCL‐NOS, AITL, ALK+ ALCL, ALK‐ ALCL, NKTCL and ATLL between 2005‐2017 in our institution. We then analyzed 57 cases with either disease progression or relapse after first line therapy (PTCL‐NOS n   =   33, AITL n   =   10 , ALK‐ ALCL n   =   4 , ALK+ ALCL n   =   1 , NKTCL n   =   9 ). Overall survival (OS) and progression‐free survival (PFS) were estimated, using the Kaplan‐Meier method, and then further compared by PIT groups. Additionally, possible prognostic factors were compared by log rank test. Variables that remained significant in univariate analysis were incorporated in multivariate analysis using the Cox proportional hazard regression model to further investigate independent prognostic factors. For patients who underwent autologous or allogeneic stem cell transplant (SCT), response to therapy was evaluated before SCT. Results: Seventy‐nine patients (60%) experienced progression/relapse after first line therapy. After excluding patients who did not receive salvage treatment at our institution, we analyzed the remaining 57 cases with progression/relapse (PTCL‐NOS n   =   33 , AITL n   =   10 , ALK‐ ALCL n   =   4 , ALK+ ALCL n   =   1 , NKTCL n   =   9 ). The overall response rate (ORR) and complete response (CR) rates at progression/relapse were 46% (95% CI: 32.4‐59.3%) and 25% (95% CI: 14.1‐37.8%), respectively. The median OS was 13 months (95% CI: 6‐23 months) and PFS was 3 months (95% CI: 2‐7months). There were no cases with ATLL in progression/relapse as all patients with ATLL were either too frail to receive salvage therapy after first progression/relapse, or proceeded to SCT in first remission. Neither PIT at diagnosis nor at first progression/relapse was predictive of OS after relapse. Moreover, there was no correlation between PIT and OS in an analysis limited to the patients with PTCL‐NOS. Multivariate analysis revealed that presence of B‐symptoms (HR: 4.83, 95% CI: 2.10‐11.0, P  < .001) and performance status (PS) greater than 1 (HR: 6.13, 95% CI: 1.84‐20.4, P  = .003) were significantly associated with inferior OS. Achieving complete or partial remission after first line therapy was associated with superior OS (HR 9.34, 95% CI 0.16‐0.71, P  = .003). Complete or partial remission after first line therapy was the only independent predictive factor for PFS (HR 0.31, 95% CI: 0.15‐0.65, P  = .002). Summary/Conclusion: The presence of B‐symptoms and poor PS at progression/relapse were associated with poor OS. Achieving complete or partial remission after first line therapy was associated with better OS. To our knowledge, B‐symptoms and response to previous therapy have never been reported as independent prognostic factors. A study with a larger sample size and longer follow‐up period is warranted to further assess the validity of these factors.