18F-FDG-PET/CT response after first-line treatment as a prognostic factor for survival in peripheral T-cell lymphoma: a Spanish retrospective study.

BACKGROUND: An accurate assessment of tumor viability after first-line treatment is critical for predicting treatment failure in peripheral T-cell lymphomas (PTCLs). 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) has been adopted as the preferred assessment method in clinical trials, but its impact in clinical practice should be examined. This study aims to determine the prognostic significance of18F-FDG-PET/CT for survival following first-line treatment in PTCL patients. RESEARCH DESIGN AND METHODS: Retrospective observational study including 175 patients diagnosed with PTCL between 2008 and 2013 in 13 Spanish sites. RESULTS: Fifty patients were evaluated with18F-FDG-PET/CT following first-line therapy: 58% were18F-FDG-PET/CT-negative and 42% were18F-FDG-PET/CT-positive. Disease progression occurred in 37.9% of18F-FDG-PET/CT-negative patients and in 80.9% of18F-FDG-PET/CT-positive patients (p = 0.0037). Median progression-free survival and overall survival were 67 and 74 months for18F-FDG-PET/CT-negative patients, and 5 (p < 0.0001) and 10 months (p < 0.0001), respectively, in18F-FDG-PET/CT-positive patients. After multivariate analysis, only B symptoms emerged as a negative predictive factor of complete response (RR 7.08; 95% CI 1.60-31.31; p = 0.001). CONCLUSIONS: 18F-FDG-PET/CT identifies high-risk PTCL patients who will have poor prognosis and survival following first-line treatment. However, more research is needed to confirm the best treatment options for PTCL patients.

Clinical and pathological characteristics of peripheral T-cell lymphomas in a Spanish population: a retrospective study.

We investigated the clinicopathological features and prognostic factors of patients with peripheral T-cell lymphoma (PTCL) in 13 sites across Spain. Relevant clinical antecedents, CD30 expression and staining pattern, prognostic indices using the International Prognostic Index and the Intergruppo Italiano Linfomi system, treatments, and clinical outcomes were examined. A sizeable proportion of 175 patients had a history of immune-related disorders (autoimmune 16%, viral infections 17%, chemo/radiotherapy-treated carcinomas 19%). The median progression-free survival (PFS) and overall survival (OS) were 7·9 and 15·8 months, respectively. Prognostic indices influenced PFS and OS, with a higher number of adverse factors resulting in shorter survival (P < 0·001). Complete response (CR) to treatment was associated with better PFS (62·6 vs. 4 months; P < 0·001) and longer OS (67·0 vs. 7·3 months; P < 0·001) compared to no CR. CD30 was expressed across all subtypes; >15% of cells were positive in anaplastic lymphoma kinase-positive and -negative anaplastic large-cell lymphoma and extranodal natural killer PTCL groups. We observed PTCL distribution across subtypes based on haematopathological re-evaluation. Poor prognosis, effect of specific prognostic indices, relevance of histopathological sub-classification, and response level to first-line treatment on outcomes were confirmed. Immune disorders amongst patients require further examination involving genetic studies and identification of associated immunosuppressive factors.