Gastrointestinal (GI) lymphoma is the most frequently diagnosed form of lymphoma in the cat and is categorized into two distinct forms based on the size of neoplastic lymphocytes. Treatments for both large- and small-cell GI lymphoma have been described previously; however, multiple chemotherapy protocols were used, a minimal amount of histopathological characterization was provided, and, in most studies, the majority of diagnoses were obtained via endoscopic pinch biopsies. Twenty-eight cats (24 with full-thickness intestinal biopsies) were diagnosed with small-cell GI lymphoma and treated with a combination of chlorambucil and glucocorticoids. The majority of cases were strongly CD3+, and many displayed epitheliotropism. The overall clinical response rate was 96%, with a median clinical remission duration of 786 days. Follow-up identified seven cats with relapsed disease—all of which were treated with a rescue protocol of cyclophosphamide and glucocorticoids; the response rate was 100%, and four of the 28 cats were diagnosed with a second malignancy.

This study is a concurrent comparison of two versions of CHOP protocols, a 19‐week CHOP and a comparatively overall dose‐intense 12‐week CHOP. The 12‐week protocol was designed to be 58% more dose intense than the 19‐week protocol for both doxorubicin and cyclophosphamide; however, it was 21% less dose intense for vincristine (VCR). Forty‐seven dogs were included for evaluation, and the characteristics of each population were similar. For dogs receiving the 19‐week CHOP protocol, 89.5% experienced a complete response, with a median progression‐free survival (PFS) of 245 days and median overall survival (OS) of 347 days. For dogs receiving the 12‐week CHOP protocol, 89.3% experienced a complete response, with a median PFS of 141 days and median OS of 229 days. When evaluated by Log‐rank analysis, the difference of PFS (P = 0.047) and OS (P = 0.013) between the groups were statistically significant. In summary, these data suggest that despite overall increased dose‐intensity, dogs receiving treatment with a 12‐week CHOP protocol experience less durable remission than our standard 19‐week protocol in this population. Additional prospective investigation will be required to explore the implication that VCR dose intensity and/or shorter overall temporal drug exposure in this protocol may result in diminished efficacy.

Combination chemotherapy holds promise for improving outcomes in malignancy when compared with single-agent approaches. Care must be taken to avoid overlapping toxicity and to utilize agents with differing mechanisms of action. A phase I dose-finding trial was performed to determine the maximally tolerated dose (MTD) of a concurrent toceranib and doxorubicin (DOX) combination protocol where toceranib dose was maintained at or near 2.75 mg kg by mouth every other day (PO EOD) while escalating DOX dosage. The dose-limiting toxicity was found to be neutropenia and the MTD of the combination was determined to be 25 mg m of DOX q 21 days given concurrently with toceranib 2.75 mg kg PO EOD. This combination was well tolerated with no excessive gastrointestinal toxicity nor novel adverse events (AEs) noted. Anti-tumour activity was observed in the majority of cases. This combination warrants further investigation in the context of phase II/III clinical trials to characterize efficacy and long-term AE profiles.

Background Metastasis of appendicular osteosarcoma is most common to the lungs and is generally considered a terminal event in dogs. Behavior and prognosis associated with cutaneous or subcutaneous metastases (CSM) is poorly defined. Objective Describe the population and gather prognostic information regarding appendicular osteosarcoma with CSM in dogs. Animals Twenty dogs with appendicular osteosarcoma and CSM. Methods Retrospective case series. Medical records were searched to identify dogs diagnosed with appendicular osteosarcoma that developed CSM. Demographic data, order of metastatic events, and CSM clinical features were evaluated. Kaplan‐Meier survival curves were constructed and log‐rank tests were used to compare survival between groups of dogs. Results In 19 dogs (95%), CSM was an incidental finding. Seventeen dogs (85%) developed pulmonary metastasis, and 1 dog (5%) developed bone metastasis. No other metastatic sites were detected before euthanasia. The median CSM‐free interval and CSM survival time were 160 days (range: 0‐542 days) and 55 days (range: 5‐336 days), respectively. The median CSM survival time was significantly longer for dogs treated with surgery and chemotherapy (94 days) or chemotherapy only (64 days) than for dogs that did not receive these treatments (11 days) (P = .002 and P = .03, respectively). No other factors were associated with survival after diagnosis of CSM. Conclusion and Clinical Importance The skin or subcutaneous tissue can be the first osteosarcoma metastatic site detected. After CSM diagnosis, the prognosis is grave with median survival <2 months. Although this finding could have been biased by case selection, treatment with surgery and chemotherapy may improve outcome.

Objectives Non-steroidal anti-inflammatory drugs (NSAIDs) are infrequently utilized in cats due to concern for renal compromise; however, recent studies demonstrate tolerability of low dose meloxicam. Toceranib phosphate is used to treat several feline cancers and is well tolerated. This study aimed to determine the tolerability and adverse event profile of combined toceranib and low dose meloxicam in cancer-bearing cats. Secondary goals involved assessing anticancer tumor efficacy and impact upon quality of life and analgesia. Methods Cats with any cancer not involving the kidneys were eligible. The study adopted a conventional 3 + 3 dose escalation design. Toceranib was administered every other day at a standard dose with meloxicam administered in an escalating fashion in subsequent cohorts, at a starting dose of 0.01 mg/kg on opposite days to toceranib, up to a maximum of 0.02 mg/kg daily, based upon previous safety studies. Laboratory work, blood pressure, tumor measurements, pain score and client-completed quality-of-life surveys were recorded every 2–4 weeks during the 12-week study period. Results Twenty-one cats were enrolled. When combined with toceranib, a meloxicam dose of 0.02 mg/kg q24h was safe and well tolerated, with no cats being withdrawn due to adverse events from the drug combination. The majority of cats demonstrated clinical benefit with stable to mildly improved tumor measurements, quality of life and pain scores. Conclusions and relevance Low dose meloxicam combined with toceranib is safe and well tolerated in cancer-bearing cats. Continued patient recruitment and data collection are needed to determine the maximum tolerated dose of meloxicam. The results of our study will guide further phase II/III trials.