Diagnostic and prognostic importance of chromosomal aberrations identified in 61 dogs with lymphosarcoma.

To determine the diagnostic and/or prognostic importance of chromosomal aberrations identified in dogs with malignant (non-Hodgkin's) lymphoma, clinical stages for 61 dogs with lymphosarcoma were determined, the lymph node(s) were histopathologically graded, and the malignant tissue lymphocytes were karyotyped. The results from life table survival curve analysis demonstrated that first remission length and survival time were significantly longer in 15 of 61 (25%) dogs that had a trisomy of chromosome 13 as the primary chromosomal aberration than in those dogs (46/61, 75%) with other primary chromosomal aberrations (P < 0.05). Sex, age, weight, histopathologic subtype and grade, World Health Organization (WHO) clinical stage, WHO and modified Karnofsky performance status, chromosomal modal number, and treatment protocol were of no prognostic importance in predicting first remission length or survival time (P > 0.05). Multivariate analysis did not identify a significant correlation between the prognostic groups or within the various prognostic subsets (P > 0.05). The pathogenesis of canine and human non-Hodgkin's lymphoma, as observed cytogenetically, differs.