Affiliation:
1. Białobrzeska Veterinary Clinic Warsaw Poland
2. Department of Diagnostics and Clinical Sciences Institute of Veterinary Medicine, Faculty of Biological and Veterinary Sciences Nicolaus Copernicus University Torun Poland
3. Division of Veterinary Epidemiology and Economics Institute of Veterinary Medicine Warsaw University of Life Sciences (SGGW) Warsaw Poland
4. Division of Animal Pathology Department of Pathology and Veterinary Diagnostics Institute of Veterinary Medicine Warsaw University of Life Sciences (SGGW) Warsaw Poland
Abstract
AbstractBackgroundThe aim of this study was to determine and describe the prognostic role of the morphological subtype determined according to the updated Kiel classification in dogs with high‐grade T‐cell lymphomas (HGTCLs) depending on the treatment applied.ObjectivesThe HGTCLs were classified into three subtypes according to the updated Kiel classification: pleomorphic mixed (PM), lymphoblastic lymphoma/acute lymphoblastic leukaemia and plasmacytoid (P). The treatment was divided into a palliative therapy (PlT) group and a chemotherapy (ChT) group.MethodsThe study was conducted between 2009 and 2017, and it enrolled 58 dogs in which cytomorphological and immunocytochemistry diagnoses were HGTCL.ResultsOverall survival (OS) was significantly longer in the ChT group (median OS—4 months, interquartile range [IQR] from 2 to 8 months) than in the PlT group (median OS—6 weeks, IQR from 1 week to 3 months).In the PlT group, PM subtype and glucocorticosteroids (GCSs) treatment proved significantly and independently linked to longer OS and approximately three‐fold lower risk of death during the study period (adjusted hazard ratio [HRadj] = 0.26, confidence interval [CI] 95%: 0.08–0.81; p = 0.020 and HRadj = 0.30, CI 95%: 0.11–0.77; p = 0.013, respectively), although due to small group size, precision of estimations was poor (wide CI 95%).In the ChT group, >7 days elapsing between diagnosis and the beginning of chemotherapy and GCS treatment prior to chemotherapy were significantly associated with lower chance of complete remission (CR; p = 0.034 for both); GCS treatment prior to chemotherapy was significantly associated with shorter OS (p = 0.016); chemotherapy based on the modified CHOP protocol was significantly associated with higher chance of CR (p = 0.034) and longer OS (p = 0.039); and CR was significantly linked to longer OS (p = 0.001).Clinical significanceThe morphological subtype of HGTCL has some prognostic value in dogs treated palliatively (with PM subtype associated with longer OS than P subtype); however, this effect is no longer visible when a dog is treated with chemotherapy.