Novel and simple prognostic index for nasal natural killer/T-cell lymphoma.
BACKGROUND
Few studies have investigated the prognostic factors for nasal natural killer (NK)/T-cell lymphoma.


METHODS
This was a retrospective multicenter clinical study. The clinical records of 36 patients with nasal NK/T-cell lymphoma who had been first treated between 1996 and 2011 were collected from 12 hospitals.


RESULTS
High serum levels of C-reactive protein (≥1.0 mg/dL), lactate dehydrogenase (≥350 IU/L), and soluble interleukin-2 receptor (sIL-2R; ≥600 U/mL) were associated with worse prognosis. A prognostic score was devised by totaling the number of these 3 predictors: 0 or 1 = score 0; and 2 or 3 = score 1. As for tumor invasion, local invasion beyond the nasal cavity was associated with poor prognosis, and a prognostic score was devised as: tumor restricted to nasal cavity, yes = score 0; no = score 1. A novel prognostic index (NPI) was established based on these scores from 0 to 2. Disease-specific survival rates at 5 years were: 90.0% for NPI = 0; 29.3% for NPI = 1; and 0.0% for NPI = 2.


CONCLUSION
Our NPI is valid for anticipating prognosis of nasal NK/T-cell lymphoma.