Prognostic biomarkers in patients with localized natural killer/T‐cell lymphoma treated with concurrent chemoradiotherapy

Concurrent chemoradiotherapy has become one of the standard management approaches for newly diagnosed localized nasal natural killer (NK)/T‐cell lymphoma (NKTCL). Few data are available on the prognostic biomarkers of NKTCL among patients treated with concurrent chemoradiotherapy. To evaluate the prognostic significance of immunophenotypic biomarkers for patients treated with concurrent chemoradiotherapy, latent membrane protein 1 (LMP1), cutaneous lymphocyte antigen (CLA) and cell origin were examined in samples from 32 patients who were enrolled in the Japan Clinical Oncology Group 0211 trial and treated with concurrent chemoradiotherapy. LMP1 and CLA were positive in 66% (19/29) and 29% (9/31) of the cases examined, respectively. The median follow‐up duration was 68 months (range, 61–94). The patients with LMP1‐positive tumors showed a better overall survival (OS) than the patients with LMP1‐negative tumors (hazard ratio, 0.240; 95% confidence interval [CI], 0.057–1.013; 80% CI, 0.093–0.615; P = 0.035). All five patients with LMP1‐negative tumors who experienced disease progression died of lymphoma, and both patients with local failure had LMP1‐negative tumors. There was no significant difference in OS according to CLA expression. A total of 27 (84%) cases were of NK‐cell origin, two were of αβ T‐cell origin and three were of γδ T‐cell origin. In contrast to those with tumors of NK‐cell origin, all five patients with NKTCL of T‐cell origin were alive without relapse at the last follow up. Our results indicate that LMP1 expression is a favorable prognostic marker and suggest that a T‐cell origin of the tumor may be a favorable prognostic marker for patients with localized NKTCL treated with concurrent chemoradiotherapy. Latent membrane protein 1 expression correlates with a favorable overall survival in patients with localized NK/T‐cell lymphoma (NKTCL) treated with concurrent chemoradiotherapy. All patients with NKTCL of T‐cell origin survived more than 5 years without recurrence in a clinical trial of concurrent chemoradiotherapy.