The Neutrophil-to-Lymphocyte Ratio Is Prognostic in Patients with Early Stage Peripheral T-Cell Lymphoma

Introduction: Peripheral T-cell lymphoma (PTCL) encompasses a group of rare and aggressive lymphomas. PTCL, unspecified (PTCLU) is the most common subtype of PTCL, and carries a poor prognosis. The International Prognostic Index (IPI) and the Prognostic Index for PTCLU (PIT) scoring systems are powerful risk-stratification tools in patients with PTCL. The neutrophil-to-lymphocyte ratio (NLR) has shown to be prognostic in patients with advanced stage PTCLU (Beltran Leuk Lymphoma 2016). The aim of this study was to evaluate whether the NLR is a prognostic factor in patients with early stage PTCLU.

Methods: We included patients with a pathological diagnosis of PTCLU who were diagnosed and treated at our institution between 2001-2016. We excluded cases with stage 3 or 4 disease. IRB approval was obtained prior to research. Pathological samples were reviewed by hematopathologists to confirm the diagnosis. Pertinent clinicopathological data were collected through chart review, and are presented using descriptive statistics. The NLR was calculated by dividing the neutrophil by the lymphocyte count, and dichotomized in NLR>=4 and NLR<4. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate Cox models were fitted to evaluate hazard ratios (HR) for overall survival (OS).

Results: 48 patients with a diagnosis of early stage PTCL were included in this analysis. Histologically, 40 patients (83%) were PTCL, unspecified, 7 (15%) were anaplastic large cell lymphoma, and 1 (2%) was enteropathy-associated T-cell lymphoma. The median age at diagnosis was 60 years (range 18-83 years) with a slight male predominance (82%). Clinically, 49% of patients were 60 or older, 34% presented with ECOG>1, 36% with elevated LDH, and 65% with extranodal disease; 44% had stage II and 56% had stage I disease. No patient had bone marrow involvement. 30% of patients presented with high/high-intermediate IPI score and 34% with high/high-intermediate PIT score. 27% of patients had a NLR >=4. There were no differences in age, LDH levels, extranodal involvement and stage between NLR>=4 and NLR<4. There was a trend towards worse ECOG performance status in NLR>=4 patients (p=0.06). The 3- and 5-year OS rates were 67% (95% CI 50-80%) and 52% (95% CI 29-71%), respectively. High/high-intermediate IPI score was associated with a worse outcome (HR 4.9, 95% CI 1.7-14.2; p=0.004), as well as high-high-intermediate PIT score (HR 3.9, 95% CI 1.2-12.7; p=0.03). According to NLR, NLR>=4 patients had a higher risk of death (HR 9.9, 95% CO 3.2-30.1; p<0.001). In a multivariate analysis adjusting for IPI and PIT scores, NLR>=4 was the only independent factor associated with a worse survival (HR 6.2, 95% CI 1.9-20.9; p=0.003).

Conclusion: The NLR appears as a novel and easy to use prognostic factor for OS in previously untreated patients with early-stage PTCL. Our findings support the need for validation of the NLR in larger retrospective or prospective studies in patients with PTCL.