Treatment outcomes and prognostic factors of feline splenic mast cell tumors: A multi-institutional retrospective study of 64 cases.

BACKGROUND: Mast cell tumors (MCT) are common splenic tumors in cats, but there is limited information on treatment outcomes of cats with this disease. MATERIALS AND METHODS: This retrospective study evaluated treatment outcomes in 64 cats with splenic MCT. Cats were categorized into the following treatment groups: splenectomy (A, n = 20); splenectomy with chemotherapy (B, n = 20); chemotherapy alone (C, n = 15); or supportive care (D, n = 9). RESULTS: Median tumor specific survival (MTSS) was: 856, 853, 244, 365 days for groups A, B, C, and D, respectively. The MTSS was not significantly different between the 4 groups. However, comparing cats that had splenectomy (A and B) versus those that did not (C and D), the MTSS was 856 and 342 days, respectively (p=0.008). None of the prognostic factors analyzed significantly influenced survival. CONCLUSION: Splenectomy (+/- chemotherapy) significantly prolongs survival in cats with mast cell tumors. The role of chemotherapy remains unknown.

Association between environmental factors including second-hand smoke and primary lung cancer in dogs.

OBJECTIVES: To estimate prevalence of exposure to environmental tobacco smoke and other environmental toxins in dogs with primary lung tumours and to analyse association between exposure and lung tumour development. MATERIALS AND METHODS: In this case-control study, an owner survey was developed to collect data on patient characteristics, general health care and environmental exposures. Dogs diagnosed with primary lung carcinomas formed the Case group. Dogs diagnosed with mast cell tumours served as Control Group 1 and dogs diagnosed with neurologic disease served as Control Group 2. Associations between diagnosis of primary lung tumour and patient and environmental exposure variables were analysed using bivariate and multivariate statistical methods. RESULTS: A total of 1178 owner surveys were mailed and 470 surveys were returned and included in statistical analysis, including 135 Cases, 169 dogs in Control Group 1 and 166 dogs in Control Group 2. An association between exposure to second-hand smoke and prevalence of primary lung cancer was not identified in this study. CLINICAL SIGNIFICANCE: Second-hand smoke is associated with primary lung cancer in people but a definitive association has not been found in dogs. The results of this study suggest that tobacco smoke exposure may not be associated with primary lung cancer development in dogs but study limitations may have precluded detection of an association.

Treatment of feline intermediate- to high-grade lymphoma with a modified university of Wisconsin-Madison protocol: 119 cases (2004-2012).

CHOP-based (cyclophosphamide, doxorubicin, vinca alkaloid, prednisolone) chemotherapy protocols are often recommended for treatment of feline lymphoma. While maintenance-free CHOP-based protocols have been published and readily used in dogs, there is limited literature regarding similar maintenance-free protocols in cats. The purpose of this study was to describe the outcome of cats with intermediate- to high-grade lymphoma that were prescribed a modified 25-week University of Wisconsin-Madison (UW-25) chemotherapy protocol. A secondary objective was examination of potential prognostic factors. One hundred and nineteen cats from five institutions treated with a UW-25-based protocol were included. The Kaplan-Meier median progression-free interval (PFI) and survival time (MST) were 56 and 97 (range 2-2019) days, respectively. Cats assessed as having a complete response (CR) to therapy had significantly longer PFI and MST than those with partial or no response (PFI 205 versus 54 versus 21 days, respectively, P < 0.0001 and MST 318 versus 85 versus 27 days, respectively, P < 0.0001).

Randomized phase III trial of piroxicam in combination with mitoxantrone or carboplatin for first-line treatment of urogenital tract transitional cell carcinoma in dogs.

BACKGROUND: Reported response rates of transitional cell carcinoma (TCC) in dogs to piroxicam in combination with either mitoxantrone or carboplatin are similar; however, it is unknown whether either drug might provide superior duration of response. HYPOTHESIS/OBJECTIVES: To determine if the progression-free interval (PFI) of dogs with TCC treated with mitoxantrone and piroxicam was different than that of dogs receiving carboplatin and piroxicam. The hypothesis was that the efficacy of mitoxantrone is no different from carboplatin. ANIMALS: Fifty dogs with TCC without azotemia. METHODS: Prospective open-label phase III randomized study. Either mitoxantrone or carboplatin was administered every 3 weeks concurrently with piroxicam with restaging at 6-week intervals. Twenty-four dogs received carboplatin and 26 received mitoxantrone. RESULTS: Response was not different between groups (P = .56). None of the dogs showed complete response. In the mitoxantrone group, there were 2 (8%) partial responses (PR) and 18 (69%) dogs with stable disease (SD). In the carboplatin group, there were 3 PR (13%) and 13 (54%) dogs with SD. The PFI was not significantly different between groups (mitoxantrone = 106 days; carboplatin = 73.5 days; P = .62; hazard ratio 0.86; 95% confidence interval 0.47-1.56). Dogs with prostatic involvement experienced a shorter survival (median, 109 days) compared to dogs with urethral, trigonal, or apically located tumors; this difference was significant (median 300, 190, and 645 days, respectively; P = .005). CONCLUSIONS AND CLINICAL IMPORTANCE: This study did not detect a different in outcome in dogs with TCC treated with either mitoxantrone or carboplatin in combination with piroxicam.