Leukocyte ratios correlate with outcome in several human cancers. Little is known about their prognostic significance in mast cell tumour (MCT). The aim of the study was to evaluate the prognostic significance of pretreatment leukocyte concentrations and their ratios in dogs with MCT for survival. Medical records of 92 dogs with MCT were retrospectively reviewed. Tumour diagnosis was made by tumour biopsy or fine-needle aspirate. Only dogs without prior treatment were included. Eosinophil, lymphocyte, monocyte and neutrophil concentration were obtained by ADVIA 2120™ (Siemens Healthcare, Vienna, Austria). Neutrophil-to-eosinophil ratio (NER), lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR) were calculated from collected leukocyte concentrations. Relative eosinophil concentration (REC), NER (P < 0.001), NLR (P = 0.001) and LMR (P < 0.001) were significant prognostic factors for outcome in univariate analysis. REC (P = 0.008) and NER (P = 0.001) remained independent predictors of survival in multiple analyses. Leukocyte concentrations and ratios, especially REC and NER may serve as prognostic indicators in MCT.

Objectives The purpose of this study was to specify lymphoma subtypes according to the World Health Organization (WHO) classification in a group of cats and to investigate their potential prognostic value. Methods Records of cats from the University of Veterinary Medicine Vienna suffering from lymphoma were reviewed in this retrospective study. To diagnose various subtypes specified in the WHO classification, histopathological and immunohistochemical examinations, as well as clonality assays in some cases, were performed. Results Of the 30 cats included in this study and classified according to the WHO guidelines, peripheral T-cell lymphoma was the most prevalent lymphoma subtype (37% of cases; n = 11), followed by diffuse large B-cell (23%; n = 7), intestinal T-cell (10%; n = 3), T-cell-rich B-cell (10%; n = 3), large granular lymphocytic (7%; n = 2), anaplastic large T-cell (7%; n = 2), B-cell small lymphocytic (3%; n = 1) and T-cell angiotropic lymphoma (3%; n = 1). The median survival time (MST) was 5.4 months (range 6 days to 2.2 years), with two cats still alive after 1.7 and 2.0 years, respectively. Treating cats prior to chemotherapy with glucocorticoids did not worsen their prognosis. Adding to chemotherapy, radiotherapy or surgery did not improve the clinical outcome. We observed that patients with intestinal T-cell lymphoma lived significantly longer (MST 1.7 years) than those with a diffuse large B-cell (MST 4.5 months) or peripheral T-cell lymphoma (MST 6.1 months). Cats with T-cell-rich B-cell lymphoma survived significantly longer (MST 1.2 years) than those with a diffuse large B-cell lymphoma. Conclusions and relevance A detailed diagnosis of feline lymphoma can be obtained by allocating different subtypes according to the WHO classification. From the eight detected lymphoma subtypes, two, intestinal T-cell lymphoma and T-cell-rich B-cell lymphoma, showed promising survival times in cats.

In humans B‐symptoms refer to systemic symptoms of lymphoma such as fever, weight loss, and night sweats and influence the prognosis of patients. In canine lymphoma, substage B is used to describe any clinical sign observed. Aim of the retrospective study was to compare the prognostic value of substage B with B‐symptoms to predict treatment response and survival in canine nodal diffuse large B‐cell lymphoma. Affected dogs treated with CHOP chemotherapy between 2008 and 2019 were included. B‐symptoms were defined by weight loss greater than 10% of normal weight, fever and the occurrence of unexplained resting tachypnoea substituted human night sweats. Substage B was defined as any symptoms but lymphadenopathy. Fifty‐five cases were included. B‐symptoms were present in 20/55 (36%) and substage B in 40/55 (74%) patients. No significant associations between B‐symptoms or substage B and weight, sex, breed, WHO stage and lymphoma grade were found. Treatment response was negatively associated with both substage B (P = .02) and B‐symptoms (P = .001). B‐symptoms significantly decreased progression free survival (PFS) (95 vs 330 days, P = .001) and lymphoma specific survival (LSS) (160 vs 462 days, P = .001). Data showed that B‐symptoms might be a more reliable prognostic indicator than substage B in canine nodal diffuse large B‐cell lymphoma. Prospective studies assessing B‐symptoms in a larger cohort of patients and in other common lymphoma types are warranted. The abstract was presented at the fourth meeting of the European Canine Lymphoma Network Group in Lugano, 22 June 2019 and published in the proceeding of the meeting on the page 26.

Objective. Based on cell kinetics, post-operative adjuvant chemotherapy should eradicate microscopic cancer cells. The appropriate timing of chemotherapy following amputation for osteosarcoma is unknown. We retrospectively examined the time interval (TI) between amputation and chemotherapy initiation in dogs with appendicular osteosarcoma without distant metastases, and whether TI played any role in outcome.Aims of the analysis were to evaluate whether an optimum TI for initiating adjuvant chemotherapy and/or a TI after which treatment benefit became negligible could be identified. Animals. 168 client-owned dogs.Procedures. Dogs were classified into 8 groups based on whether they received chemotherapy within 3, 5, 7, 10, 15, 20, 30 or >30 days after surgery. Univariate and multivariate analyses were performed to determine the prognostic factors of progression and survival outcomes.Results. The median TI between surgery and chemotherapy was 14 days (range, 1-210).Median time to progression of dogs receiving chemotherapy within 5 days [375 (95%CI,] was significantly longer than that of dogs treated after 5 days [202 (95%CI,]; P = 0.005]. Median overall survival of dogs receiving chemotherapy within 5 days [445 (95%CI, 345-545)] was significantly longer than that of dogs treated after 5 days [239 (95%CI,]; P = 0.003]. The survival benefit of chemotherapy was lost with a delay of 4 weeks from amputation.Conclusions and clinical relevance. The present analysis showed a significant association with survival for earlier delivery of adjuvant chemotherapy. These results suggest that the timing of chemotherapy may be an important prognostic variable.

Recent literature suggests a combination of flow cytometric determination of Ki‐67 and immunophenotype as a reliable tool to classify canine lymphomas. Immunohistochemistry (IHC) on histological samples is the gold standard technique assessing Ki‐67 index. Agreement between IHC and FCM derived Ki‐67 indices has never been investigated. The aim of this study was to investigate the agreement between IHC and FCM in the assessment of Ki‐67 expression/index, in order to evaluate whether FCM may serve as a non‐invasive alternative method for the estimation of proliferative activity in canine lymphoma. Dogs with previously untreated canine lymphoma undergoing diagnostic lymphadenectomy were prospectively enrolled. Ki‐67 expression/index was assessed by FCM and IHC and expressed as percentage of positive cells. 39 dogs classified by histopathology matched the inclusion criteria. With both methods, Ki‐67 expression/index was higher in intermediate/high‐grade lymphomas. Spearman's coefficient of correlation was ρ = 0.57; (95% CI0.33‐0.75) suggesting a moderate correlation. A Bland‐Altman plot revealed a negative constant bias of −3.55 (95% CI: −10.52 to 3.42) with limits of agreement from −45.71 to 38.61. The study confirmed agreement albeit with wide confidence intervals between the values of Ki‐67 expression/index assessed with FCM and IHC. Discrepancies were observed in a subset of cases. Possible explanation could be that Ki‐67 index in IHC is determined in the most proliferative areas of the slide, which could introduce kind of sampling bias, whereas FCM evaluates many more cells in cell suspension. Further studies are warranted to investigate this phenomenon.