Combined chemoradiation for the management of nasal natural killer (NK)/T-cell lymphoma: elucidating the significance of systemic chemotherapy.

The objective of this analysis was to evaluate the efficacy and treatment outcome of CHOP and CHOP combined with nitrosourea chemotherapy in natural killer (NK)/T-cell lymphoma of the nasal cavity. Sixty-three patients with NK/T-cell lymphoma of the nasal cavity were treated with CHOP or CHOP combined with oral nitrosourea chemotherapy between January 1997 and June 2005. By the Ann Arbor Lymphoma Staging Classification, 57 patients (90%) had Stage IE or IIE disease and six patients (10%) had Stage III or IV disease. All patients with Stage IE or IIE disease were intended to be treated curatively with combined chemoradiation; and patients who had Stage III or IV disease were treated with chemotherapy alone with curative intention. Chemotherapy consisted of: (1) up to six cycles of the standard CHOP based regimen, or (2) up to six cycles of the standard CHOP based regimen with oral Semustine dosed at 120 mg (or Lomustine dosed at 100mg) on day 1 of each chemotherapy cycle. External beam radiation therapy was delivered by daily conventional fractionation by Co-60 or 6MVx linear accelerator for patients with Stage IE or IIE disease. The radiation dose to the tumor bed was between 36 and 50 Gy with a median dose of 45 Gy. Fifty-three patients received chemotherapy prior to radiation, and four patients were treated with involved field radiation before chemotherapy. The median follow up for all 44 surviving patients was 31 months (range: 6-104 months). The 2-year progression-free survival (PFS) and overall survival (OS) rates were 60% and 70%, respectively. The PFS and OS of patients who were treated with or without oral nitrosourea in addition to CHOP were 73% vs. 44% (P=0.035) and 75% vs. 64% (P=0.276), respectively. Nine patients with Stage IE or IIE diseases developed disease progression during their planned treatment and died within 10 months after the initiation of treatment; Six patients who achieved complete response (CR) after planned chemoradiation developed systemic recurrence and died at 13-48 months despite salvage treatment; one patient died of Hemophagocytic Syndrome during radiotherapy after achieving CR from chemotherapy. Three patients with Stage III or IV disease died during chemotherapy or during salvage treatment at 2, 4, and 19 months, respectively. Among the 59 patients who received chemotherapy as their initial treatment, 29, 6, 12, and 12 patients had complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) respectively after chemotherapy. The 2-year overall survival rates for these four groups of patients were 100%, 75%, 60%, and 17%, respectively (P<0.0001). Multivariate analysis revealed that International Prognostic Index (IPI) for Lymphoma, perforation of nasal septum as a presenting symptom, "B" symptoms, ECOG performance, as well as response after chemotherapy, were significant independent prognostic factors for this group of patients. The extent of response after induction chemotherapy is significantly related to the treatment outcome of patients with nasal NK/T-cell lymphoma. CHOP based chemotherapy combined with oral nitrosourea followed by involved field radiotherapy may provide improved treatment results compared to conventional CHOP chemotherapy and radiation. This strategy needs to be optimized and tested in a prospective trial for its efficacy.