Immunophenotypic and Clinical Differences Between the Nasal and Extranasal Subtypes of Upper Aerodigestive Tract Natural Killer/T-Cell Lymphoma

Purpose: To investigate, in a large cohort of patients, the immunophenotypic and clinical differences of nasal and extranasal extranodal nasal-type natural killer/T-cell lymphoma of the upper aerodigestive tract (UADT-NKTCL) and examine the relevance of the immunophenotype on the clinical behavior, prognosis, and treatment. Methods and Materials: A total of 231 patients with UADT-NKTCL were recruited. One hundred eighty-one patients had primary location in the nasal cavity (nasal UADT-NKTCL), and 50 patients had primary extranasal UADT-NKTCL. Results: Patients with extranasal UADT-NKTCL had more adverse clinical features, including advanced-stage disease, regional lymph node involvement, B symptoms, and poor performance status, than patients with nasal UADT-NKTCL. In addition, CD56 and granzyme B were less frequently expressed in extranasal UADT-NKTCL. The 5-year overall survival rate was 74.1% for the entire group and 76.0% for early-stage disease. The 5-year overall survival rate for extranasal UADT-NKTCL was similar or superior to that of nasal UADT-NKTCL for all disease stages (76.9% vs 73.4%, P=.465), stage I disease (75.9% vs 79.2%, P=.786), and stage II disease (83.3% vs 50.3%, P=.018). CD56 expression and a Ki-67 proliferation rate ≥50% predicted poorer survival for extranasal UADT-NKTCL but not for nasal UADT-NKTCL. Conclusions: Patients with nasal and extranasal UADT-NKTCL have significantly different clinical features, immunophenotypes, and prognosis. Extranasal UADT-NKTCL should be considered as a distinct subgroup apart from the most commonly diagnosed prototype of nasal UADT-NKTCL