BackgroundMolecular techniques that detect canine lymphoma cells by their clonal antigen receptor gene rearrangement play an increasing role for diagnosis as well as for monitoring minimal residual disease during and after cytostatic therapy. However, the methods currently available are time-consuming and/or cost-intensive thus impeding the use in clinical routine. The aim of the present study was to develop and evaluate a real-time polymerase chain reaction (PCR) with subsequent melting curve analysis (MCA) for the detection of clonally rearranged antigen receptor genes in dogs with B and T cell lymphoma on non formalin-fixed and paraffin-embedded lymph node samples.ResultsIn lymph node aspirates from 30 dogs with multicentric B cell lymphoma, real-time PCR with MCA detected clonal rearrangement in 100% and conventional PCR with polyacrylamide gel electrophoresis (PAGE) in 93% of samples. Both methods correctly identified clonality in 80% of lymph node aspirates of 10 dogs with T cell lymphoma. None of the two PCR systems detected clonal rearrangement in samples from 9 dogs with lymph node hyperplasia. Using a dilutional series with regular lymphoid desoxyribonucleic acid (DNA), detection limits of lymphoma DNA were as low as 0.8% and 6.25% for B and T cell clonal rearrangement with real-time PCR and MCA and at 3.13% and 12.5% with the conventional system. Median absolute detection limits of lymphoma DNA were shown to be at 0.1 ng and 1 ng for the B and T cell immunophenotype with the real-time PCR system and at 10 ng each with conventional PCR and PAGE.ConclusionsReal-time PCR with MCA is a convenient and reliable method with a good analytical sensitivity. Thus, the method may assist the detection of clonal antigen receptor gene rearrangement in canine lymphoma patients in a clinical setting also in the presence of small amounts of neoplastic cells.

Background: Different chemotherapy regimes have been described for feline lymphoma with varying outcomes. Hypothesis: In cats with lymphoma, a long-term, multiagent chemotherapy protocol will be effective and carry acceptable toxicity.Animals: Twenty-three cats with histologically or cytologically confirmed diagnosis of lymphoma. Methods: Prospective, single-arm clinical trial in which cats were treated with a chemotherapy protocol consisting of a cyclic combination of L-asparaginase, vincristine, cyclophosphamide, doxorubicin, methotrexate, and prednisolone with a planned total treatment time of 122 weeks.Results: Complete remission (CR) rate was 74% (n 5 17). Fourteen percent of cats attained partial remission (PR). Median duration of first CR was 264 days (range, 45-2,485 days). Six-month, 1-, and 2-5-year remission rates were 75, 50, and 34%, respectively. Duration of PR ranged between 23 and 63 days. Median survival in cats with CR was 296 days (range, 50-2,520 days). Six-month, 1-, 2-, and 3-5-year survival rates in cats with CR were 82, 47, 34, and 27%, respectively. Survival of cats achieving PR ranged between 38 and 120 days. Of the analyzed variables, only anatomical location had a significant influence on remission duration (P5.022). Actual median treatment time in cats with CR was 128 days (18 weeks). Hematologic and gastrointestinal toxicosis was infrequent and mostly low grade.Conclusions and Clinical Importance: In this population of cats with lymphoma, chemotherapy was effective. With infrequent and mostly low-grade toxicosis, tolerability of the protocol may be considered good.

In this group of dogs the 12-week maintenance-free chemotherapy protocol was well tolerated and had satisfactory results.

The aim of this prospective clinical trial was to investigate the efficacy and toxicity of a short-term, maintenance-free chemotherapy protocol in feline lymphoma. Twenty-six cats with confirmed diagnosis of high-/intermediate-grade lymphoma were treated with a 12-week protocol consisting of cyclic administration of L-asparaginase, vincristine, cyclophosphamide, doxorubicin and prednisolone. Complete (CR) and partial remission (PR) rates were 46 and 27%, respectively. Median duration of first CR was 394 days compared with a median PR duration of 41 days. No factor was identified to significantly influence the likelihood to reach CR. Overall survival amounted to 78 days (range: 9-2230 days). Median survival in CR cats was 454 days and in PR cats was 82 days. Toxicosis was mainly low grade with anorexia seen most frequently. In cats achieving CR, maintenance-free chemotherapy may be sufficient to attain long-term remission and survival. Factors aiding in prognosticating the likelihood for CR, strategies enhancing response and targeting chemotherapy-induced anorexia need to be identified in future.

Background: Treatment of lymphoma in dogs by long-term chemotherapy has favorable results. However, the efficacy of short-term, maintenance-free treatment protocols on remission and survival times in dogs has not been determined.Hypothesis: That treatment using a 12-week chemotherapy protocol would be associated with satisfactory treatment outcome in dogs with lymphoma.Animals: 77 dogs with histologically or cytologically confirmed diagnosis of lymphoma. Methods: Prospective clinical trial in which dogs were treated with a 12-week chemotherapy protocol consisting of Lasparaginase, vincristine, cyclophosphamide, doxorubicin, and prednisolone.Results: Complete remission rate was 76.3%. Multivariate logistic regression analysis revealed that clinical substage (P 5 .006) and immunophenotype (P 5 .003) had a significant influence on the likelihood of a dog achieving complete remission. Median duration of first complete remission was 243 days (range 19-1,191 days). The 6-month, 1-year, and 2-year remission rates were 68%, 28%, and 16%, respectively. In the multivariate analysis of patient variables, immunophenotype (P 5 .022) revealed a significant influence on first remission duration. Toxicosis was mild with the exception of 1 treatment-associated death.Conclusions and Clinical Importance: In this group of dogs the 12-week maintenance-free chemotherapy protocol was well tolerated and had satisfactory results.

Appendicular osteosarcoma (OSA) is a highly metastatic tumour in dogs. The aim of the study was to compare thoracic radiographs with thoracic computed tomography (CT) in the staging of canine appendicular OSA. In all, 39 canine patients histologically diagnosed with OSA were reviewed in the retrospective study. All dogs underwent radiographic examination as well as CT examination of the thoracic cavity. Pulmonary nodules were detected radiographically in two cases (5%), whereas the CT imaging showed that pulmonary nodules were evident in 11 cases (28%, P = 0.024). There was an improved detection of small pulmonary nodules in the lung parenchyma with CT (P = 0.021). The number of nodules in CT examination had a significant negative influence on survival time (P = 0.005). However, whether nodules were present in CT or not did not influence overall survival (P = 0.368). CT examination was superior to thoracic radiography in the screening and detection of pulmonary nodules in dogs with OSA.

Akin to the situation in humans, dogs are frequently affected by tumors of the prostate. The malignancies share many similarities between both species, for example, median age at the onset of the disease and metastatic behavior. In human prostatic tumor samples, investigations of prepared metaphase spreads showed a variety of chromosomal aberrations, with trisomies of chromosomes 7, 8, and 17 as the leading cytogenetic abnormalities. In this article we present one case of a canine adenocarcinoma of the prostate, including clinical examination and establishment of a cell line from a tumor sample obtained from the affected 10-year-old male Briard. Searching for similarities between both species in respect to chromosomal changes within the tumor samples, we investigated prepared metaphases of the canine cell line cytogenetically. These investigations presented a highly rearranged karyotype showing a large biarmed marker consisting of material from chromosomes 1 and 2 in addition to centromeric fusions between dog chromosomes 1 and 5 that both could be identified in every metaphase investigated, while centric fusions of chromosomes 4 and 5 occurred in up to 50% of the metaphases. The cell line grew very well and showed evidence of being spontaneously immortalized when it crossed the 20th passage.

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