Retrospective analysis of clinical characteristics, treatment outcomes and prognosis of patients with natural killer/T‑cell lymphoma

Natural killer/T-cell lymphoma (NKTCL) is the most common T-cell non-Hodgkin lymphoma in China; however, the clinical characteristics and optimal treatment remain unclear. The present study aimed to retrospectively assess the clinical features of patients with NKTCL and to determine treatment strategies. A total of 200 patients who were diagnosed with NKTCL and admitted to the Cancer Center, Union Hospital (Wuhan, China) between June 2013 and June 2022 were identified. Clinical data from these patients were collected and analyzed to evaluate the clinical features, treatment outcomes and prognostic factors. A total of 171 patients diagnosed with NKTCL were ultimately enrolled. Patients were diagnosed at a median age of 45 years and had a male-to-female ratio of 2:1. Out of the 171 patients, 117 were in the early stage (stage I/II; 68.4%) and 54 were in the advanced stage (stage III/IV; 31.6%) of NKTCL. Among these patients, B symptoms were present in 60.2% of patients (103/171) and the Eastern Cooperative Oncology Group performance status was scored as 0-1 in 93.6% of patients (160/171). Most patients had a low-to-moderate risk of international prognostic index (147/171; 86.0%), prognostic index for NKTCL (PINK; 122/171; 71.3%) and PINK with extended features (112/171; 65.5%). At baseline, it was demonstrated that Epstein-Barr virus DNA was positive in the serum of 166/171 patients (2.9%). Combined chemotherapy and radiotherapy at 54 Gy revealed a promising effect with the highest overall response rate (ORR) of 98.2%, a 4-year progression-free survival (PFS) rate of 82.5% [95% confidence interval (CI), 75.1-89.9%] and an overall survival (OS) rate of 92.2% (95% CI, 86.9-97.5%) for the early-stage group. Pegasparase-based chemotherapy was used to treat advanced-stage patients, resulting in a 4-year PFS rate of 62.3% (95% CI, 47.4-77.2%) and an OS rate of 63.5% (95% CI, 48.2-78.8%). The regimen containing the programmed cell death protein 1 inhibitor camrelizumab demonstrated an ORR of 100% in both the early- and advanced-stage cohorts. Moreover, stage and an age of >60 years were independent prognostic factors for poor PFS, whilst stage and elevated lactate dehydrogenase were independent prognostic factors for poor OS. In conclusion, the results indicated promising efficacy for pegaspargase-based chemotherapy in terms of response rates and survival outcomes for both early- and advanced-stage patients. However, further refinement of treatment strategies is needed.