IMPROVED SURVIVAL OUTCOMES FOR PATIENTS WITH EXTRA‐NODAL NK/T LYMPHOMA: DATA FROM 140 PATIENTS PROSPECTIVELY REGISTERED IN THE INTERNATIONAL T‐CELL PROJECT

Abstract

Introduction: Extra‐nodal NK/T cell lymphoma (NKTCL) is a distinct clinicopathological entity characterised by a cytotoxicT or NK cell phenotype and invariable Epstein Barr virus (EBV) infection of the malignant clone. An invasive nasal and upper aero‐digestive mass is the dominant clinical presentation, although extra‐nasal cases are recognised. Data from the retrospective International T‐Cell Lymphoma Project reported poor outcomes for both nasal and extra‐nasal NKTCL, with 5‐yr OS rates of 40% and 15% respectively (Au et al. Blood 2009). Method: The T‐Cell Project prospectively registered consecutive patients with newly diagnosed peripheral T cell lymphomas (PTCL) from 74 centres, in 14 countries, across 4 continents from Sep 2006 ‐Dec 2015. A key aim of this global collaborative project was to more precisely define clinical characteristics and outcome of patients with the less common subtypes of PTCL. Result: From a total of 1,369 evaluable PTCL cases, 140 (10.2%) were confirmed as NKTCL following international histopathologic panel review. As anticipated, NKTCL cases, as a proportion of all PTCL cases, varied across geographical regions (Asia 28%, South America 9.3%, U. S.A 7.6%, Europe 6.4%). The median age at diagnosis was 52.5 years with a male predominance (66%). Stage III/IV disease was seen in 39% patients, whilst bulky disease >5 cm (7.4%) and BM involvement (9.8%) were uncommon.Data on therapy was available in 111 (79%) patients, of whom 103 (93%) received chemotherapy (CHT) as part of first‐line treatment. Sixty‐four patients (58%) additionally received concurrent or sequential radiotherapy (RT), whilst 13 patients (11.7%) underwent high‐dose therapy as consolidation. Five patients (4.5%) underwent RT only, whilst 3 (2.7%) received palliative care only. Of 103 patients treated with chemotherapy, 41 (40%) received anthracycline‐containing regimens whilst 36 (35%) received Lasparaginase‐based schedules.With a median follow‐up of 39 months, (Figure Presented) the median PFS for (n = 139) NKTCL patients was 33 months (95%CI 7‐58) with marked delineation for nasal and extra‐nasal cases; 72 months (95%CI 27‐118) and 10 months (95%CI 1‐20) respectively. For the whole cohort (n = 140) the median OS was 46 months, translating to a 5‐yr OS of 56% and 34% for nasal and extra‐nasal cases respectively (p < 0.0001, Figure). Cause of death was most commonly attributable to lymphoma (61%) and infection (15%). Conclusion: This is the largest prospective international analysis of NKTCL to‐date, describing notable geographical differences in incidence and treatment approaches. With mature follow‐up, we observed significant improvements in both PFS and OS, for both nasal and extranasal subgroups, as compared to published outcomes from the previous retrospective International T‐Cell Lymphoma Project. The observed improvements in survival outcomes are most likely attributable to the adoption of modern chemotherapy regimens.