Researchers Develop Prognostic Model for Natural Killer Lymphoma

Researchers have developed 2 prognostic models for natural killer lymphoma that can be used to develop risk-adapted treatment strategies for patients with extranodal natural killer T-cell lymphoma (ENKTL). The models are specifically for patients being treated without anthracycline-based therapy.¹

Because the clinical outcomes of patients with ENKTL has improved tremendously due to novel treatment approaches with non-anthracycline-based chemotherapy and frontline use of concurrent chemoradiotherapy or radiotherapy, researchers sought to develop a new prognostic model based on the outcomes in this contemporary era.

For the retrospective study, researchers analyzed data from 527 patients with newly diagnosed, previously untreated ENKTL who received non-anthracycline-based chemotherapy with or without upfront concurrent chemoradiotherapy or radiotherapy with curative intent. Patients were treated at 38 hospitals in 11 countries.

Results showed that age greater than 60 years, stage 3 or 4 disease, distant lymph-node involvement, and non-nasal type disease were significantly associated with progression-free and overall survival.

Researchers then used these data to develop the prognostic index of natural killer lymphoma (PINK). In this model, patients are stratified as being low-risk (no risk factors), intermediate-risk (1 risk factor), or high-risk (≥ 2 risk factors), which were associated with a 3-year overall survival rate of 81% (95% CI, 75 – 86), 62% (95% CI, 55 – 70), and 25% (95% CI, 20 – 34), respectively.

A second prognostic index, PINK-E, was developed using data from 328 patients with data for Epstein-Barr virus DNA. Researchers found that a detectable viral DNA titre was independently associated with overall survival.

For this model, patients were classified as low-risk (0 or 1 risk factor), intermediate-risk (2 risk factors), or high-risk (≥ 3 risk factors), which were associated with survival rates of 81% (95% CI, 75 – 87), 55% (95% CI, 44 – 66), and 28% (95% CI, 18 – 40), respectively.

Researchers then validated and confirmed their novel prognostic models in an independent cohort of patients, but found that the PINK-E model was only significantly associated with the high-risk group compared with the low-risk group.

Reference

1. Kim SJ, Yoon DH, Jaccard A, et al. A prognostic index for natural killer cell lymphoma after non-anthracycline-based treatment: a multicentre, retrospective analysis [published online ahead of print February 9, 2016]. Lancet Oncol. doi: 10.1016/S1470-2045(15)00533-1.