[Clinical features and treatment outcome of extranodal nasal-type NK/T-cell lymphoma of the extra-upper aerodigestive tract].

Objective: To investigate the clinical features and prognosis of extranodal nasal-type NK/T-cell lymphoma of the extra-upper aerodigestive tract (extra-UADT NKTCL). Methods: The clinical data of 159 patients with extra-UADT NKTCL from the China Lymphoma Collaborative Group (CLCG) database between November 2001 and December 2015 were retrospectively analyzed. Kaplan-Meier survival analysis and Log-rank test were used to evaluate the prognosis. The Cox regression model is used for multi-factor analysis. Results: Extra-UADT NKTCL commonly occurs in skin and soft tissues (106/159, 66.7%) and gastrointestinal tract (31/159, 19.5%). The incidences of elevated lactate dehydrogenase (LDH) and Ann Arbor Ⅲ~Ⅳ stage were 47.8% (76/159) and 64.2% (102/159), respectively. The 3-year overall survival (OS) and progression-free survival (PFS) rates were 43.6% and 27.9%, respectively. The corresponding OS rates of primary skin/soft tissue site and gastrointestinal tract site were 41.0% and 59.4% (P=0.281), while the PFS rates were 24.8% and 48.3%, respectively (P=0.109). Combined modality treatment improved the 3-year OS of all the patients (58.4% vs 33.9%, P=0.001) and 3-year PFS (40.7% vs 20.7%, P=0.008) when compared with chemotherapy alone. LDH elevation, Ann Arbor synthesising and ≥2 junction external bits were intrusive as independent risk factors for total survival (P<0.05), LDH elevation and ≥2 junction outer bits were intrusive as independent risk factors for progressionless survival(P<0.05). The distant extranodal dissemination was the primary failure patterns. Conclusions: Extra-UADT NKTCL appears to have distinct clinical characteristics and poor outcome. Compared with chemotherapy alone, combined modality treatment may improve the prognosis of patients with extra-UADT NKTCL.