RISK STRATIFICATION BASED ON NCCN‐IPI AT THE TIME OF DIAGNOSIS IN COMBINATION WITH POST‐TREATMENT PET‐CT SCAN FOR THE TREATMENT OF NODAL PERIPHERAL T‐CELL LYMPHOMA

Abstract

Background: Nodal peripheral T-cell lymphomas (PTCLs) consist of PTCL not otherwise specified (NOS), angioimmunoblastic T-cell lymphoma (AITL), anaplastic large-cell lymphoma-anaplastic lymphoma kinase positive (ALCL-ALK+), and ALCL-ALK−. Clinical assessments before and after treatment are essential to predict survival in nodal PTCL. However, limited data are available regarding the prognostic significance of National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) as a pre-treatment clinical tool and post-treatment PET-CT scan indicating tumor viability in patients with nodal PTCL. The primary aim was to establish a risk model for nodal PTCL based on NCCN-IPI and post-treatment PET-CT scan. Method: In this retrospective, multicenter, cohort study, patients were eligible if they were diagnosed with nodal PTCL from Jan 2005 to June 2016, received systemic chemotherapy, and had the results of PET-CT scan at the time of diagnosis and at the end of treatment, which was assessed using 5-point Deauville score. The study excluded ALCL-ALK+. Results: A total of 396 patients were screened. Seventy patients were excluded from the analysis: unavailable pre- or post-treatment PET scans, no systemic treatment, uncertain histology, and ALCL-ALK+. Thus, 326 patients were analyzed. The median age was 61 years (range, 18–86) and 209 (64%) were male. PTCL-NOS (N = 172, 53%) was the most common subtype, and AITL (N = 111, 34%) and ALCL-ALK− (N = 43, 13%) followed. Patients were categorized into low (N = 42, 13%), low-intermediate (LI, N = 108, 33%), high-intermediate (HI, N = 136, 42%), and high (N = 40, 12%) risk groups according to the NCCN-IPI. Based on the Deauville criteria, post-treatment PET-CT scan was scored as 1 (N = 130, 40%), 2 (N = 47, 14%), 3 (N = 60, 18%), 4 (N = 27, 8%), and 5 (N = 62, 19%). Because the number of progression in Deauville score 3 (40/60, 67%) was significantly different from score 2 (21/47, 45%; P = 0.023) and 4 (24/27, 89%; P = 0.030), we categorized patients into 3 groups: Deauville score 1–2, 3, and 4–5. With a median follow-up of 54.7 months (IQR, 30.2–84.5), 5-year PFS rate was 35.7% (95% CI, 30.0–41.4), and OS rate was 47.1% (95% CI, 40.8–53.4). NCCN-IPI risk and post-treatment PET-CT scan were independently associated with PFS in multivariate analysis (for LI NCCN-IPI, hazard ratio [HR] 1.615, 95% CI 0.838–3.113; HI NCCN-IPI, HR 3.063, 95% CI 1.626–5.769; high NCCN-IPI 4.475, 95% CI 2.231–8.977; P < 0.001: for post-treatment Deauville score 3, HR 1.895, 95% CI 1.281–2.801; score 4–5, HR 6.916, 95% CI 4.948–9.667; P < 0.001). We stratified patients into 5 groups based on risk of progression: low (low NCCN-IPI and Deauville score 1–2), INT-1 (low NCCN-IPI and score 3, or LI NCCN-IPI and score 1–2), INT-2 (HI NCCN-IPI and score 1–2), high (high NCCN-IPI and score 1–2, or LI to high NCCN-IPI and score 3), and very high (score 4–5). The risk model showed a strong association with PFS and OS (Figure 1). Keywords: peripheral T-cell lymphomas (PTCL); positron emission tomography (PET); prognostic indices.