Treatment Outcome of Localized Extranodal NK/T Cell Lymphoma in Nasal and Upper Aerodigestive Tract: A Single Institue Experience in Korea.

Purpose: Extranodal natural killer (NK)/T-cell lymphoma presents mostly with localized disease at diagnosis and shows predominant nasal involvement. However, the optimal treatment is not established and the role of chemotherapy as a front-line therapy is still unclear. Furthermore, treatment outcome of extranasal NK/T cell lymphoma, especially upper aerodigestive tract lymphoma has not well been documented. Thus, we performed a retrospective analysis in localized extranodal NK/T cell lymphomas occurring from nasal and upper aerodigestive tract treated with combination chemotherapy of CEOP-B as a front-line therapy.

Methods: Between January 2000 and April 2005, 43 patients with newly diagnosed extranodal NK/T-cell lymphoma were treated with CEOP-B combination chemotherapy. On day 1, cyclophosphamide, epirubicin, vincristine and bleomycin were intravenously infused, and prednisolone was orally administered for 5 days. Chemotherapy was repeated with 21 days up to 6 cycles and response was assessed every two cycles. 26 patients were treated with chemotherapy alone, while radiation therapy was given sequential to chemotherapy in 17 patients.

Results: 30 males and 13 females were enrolled. The median age of the patients was 40 years (range 20–74). Most patients had low international prognostic index scores (low: 31, low intermediate: 12). 29 patients had nasal cavity/nasopharynx involvement, and 14 patients had upper aerodigestive tract involvement. 14 CR including CR-u (CR: 8, CR-u: 6) and 16 PR was observed after the 2^nd cycle. 4 CR-u and one CR were observed from patients with PR after the completion of chemotherapy. Thus, the overall CR rate was 44.2% (19/43) and overall response rate was 67.4% (29/43). There was no difference of response rate to chemotherapy between the lymphomas from nasal cavity/nasopharynx and from the upper aerodigestive tract. However, all the 7 patients with disease progression had their primary lesion in the nasal cavity. The median overall survival for all patients was 26.87 months (95% CI: 8.71–45.03) and the median disease-free survival is 15.27 months (95% CI: 2.92–27.62). When the two groups were classified according to the site of involvement, the upper aerodigestive tract lymphomas showed longer overall survival than the nasal cavity/nasopharynx lymphomas with marginal significance (p = 0.0643). However, there was no difference in regards to disease-free survival (p = 0.1078). The patients treated with chemotherapy alone have shown the median disease-free survival (15.27 months, 95% CI: 5.77–24.76) similar to the patients treated with chemotherapy and radiotherapy (19.03 months, 95% CI: 1.07–41.97). In the univariate and multivariate analysis, there was no clinical and laboratory factors predicting reduced survival except age (older than 60 years old).

Conclusions: The frontal use of chemotherapy achieved a response rate comparable to the previous results in localized extranodal NK/T cell lymphoma, but the addition of radiation failed to show survival benefit. NK/T cell lymphomas occurring from upper aerodigestive tract showed better treatment outcomes than nasal NK/T cell lymphomas.