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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate expression of cyclooxygenase (COX)-1 and COX-2 in the urinary bladder epithelium of clinically normal dogs and in transitional cell carcinoma cells of dogs.

Animals—21 dogs with transitional cell carcinoma of the urinary bladder and 8 dogs with clinically normal urinary bladders.

Procedure—COX-1 and COX-2 were evaluated by use of isoform-specific antibodies with standard immunohistochemical methods.

Results—COX-1, but not COX-2, was constitutively expressed in normal urinary bladder epithelium; however, COX-2 was expressed in neoplastic epithelium in primary tumors and in metastatic lesions of all 21 dogs and in new proliferating blood vessels in 3 dogs. Also, COX-1 was expressed in the neoplastic cells.

Conclusions and Clinical Relevance—Lack of expression of COX-2 in normal bladder epithelium and its substantial expression in transitional cell carcinoma cells suggest that this isoform may be involved in tumor cell growth. Inhibition of COX-2 is a likely mechanism of the antineoplastic effects of non steroidal antiinflammatory drugs. (Am J Vet Res 2000;61:478–481)

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in American Journal of Veterinary Research

Abstract

Objective—To determine the accuracy of 3-D and 2-D ultrasonography for quantification of tumor volume in dogs with transitional cell carcinoma (TCC) of the urinary bladder.

Animals—10 dogs with biopsy-confirmed TCC.

Procedures—The urinary bladder of each dog was distended with saline (0.9% NaCl) solution (5.0 mL/kg), and masses were measured via 3-D and 2-D ultrasonography. Masses were also measured via 3-D ultrasonography after bladders were distended with 2.5 and 1.0 mL of saline solution/kg. Subsequently, the bladder was deflated and distended with CO2 (5.0 mL/kg); CT was performed after IV contrast medium administration. Tumor volumes were calculated via 3-D ultrasonography, 2-D ultrasonography, and CT (reference method) and compared via ANOVA, Deming regression, and Bland-Altman plots. Repeated-measures ANOVA was used to assess effects of bladder distension on 3-D tumor volume measurements. Repeatability of measurements was estimated via the coefficient of variation for each method.

Results—Repeatability was considered good for all 3 methods. There was no significant difference in tumor volume measurements obtained via 3-D ultrasonography at different degrees of urinary bladder distension. Results of Deming regression and Bland-Altman plots indicated excellent agreement between tumor volume measurement with 3-D ultrasonography and CT, but not between 2-D ultrasonography and CT.

Conclusions and Clinical Relevance—Tumor volume in dogs with TCC of the urinary bladder was accurately measured via 3-D ultrasonography. Use of 3-D ultrasonography can provide a less expensive and more practical method for monitoring response to treatment than CT and was more accurate than 2-D ultrasonography.

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in American Journal of Veterinary Research

Abstract

Objective—To evaluate the use of piroxicam for the treatment of oral squamous cell carcinoma in dogs.

Design—Prospective case series.

Animals—17 dogs with measurable oral squamous cell carcinoma.

Procedure—Dogs were treated with piroxicam at a dosage of 0.3 mg/kg (0.14 mg/lb) of body weight, PO, every 24 hours until progressive disease or unacceptable signs of toxicosis developed or the dog died.

Results—One dog had a complete remission (maxillary tumor), and 2 dogs had partial remissions (lingual tumor and tonsillar tumor). An additional 5 dogs had stable disease, including 1 with a maxillary tumor, 2 with mandibular tumors, and 2 with tonsillar tumors. Variables associated with tumor response were not identified. Median and mean times to failure for the 3 dogs that had a remission were 180 and 223 days, respectively. Median and mean times to failure for the 5 dogs with stable disease were 102 and 223 days, respectively. Time to failure was positively associated with tumor response and negatively associated with tumor size. One dog had mild adverse gastrointestinal tract effects that resolved with the addition of misoprostol to the treatment regimen.

Conclusions and Clinical Relevance—Results suggest that piroxicam may be useful in the treatment of dogs with oral squamous cell carcinoma; response rate was similar to that reported for other cytotoxic treatments. Larger-scale studies are warranted to determine what role piroxicam may have, alone or in combination with other treatments, for the treatment of dogs with oral squamous cell carcinoma. (J Am Vet Med Assoc 2001;218:1783–1786)

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in Journal of the American Veterinary Medical Association

Objective

To determine whether cisplatin administered at a dosage of 60 mg/m2 of body surface area, IV, every 21 days, would induce remission of transitional cell carcinoma of the urinary bladder in dogs.

Design

Retrospective analysis of medical records.

Animals

18 dogs with histologically confirmed transitional cell carcinoma of the urinary bladder.

Procedure

Clinical staging was performed by means of physical examination, contrast cystography or ultrasonography, and thoracic radiography prior to and 42 days after the initiation of cisplatin treatment. Dogs with clinical signs of tumor progression were reevaluated earlier than 42 days in some instances. Complete remission (CR) was defined as complete resolution of measurable tumor. Partial remission (PR) was defined as a ≥ 50% reduction in tumor volume without development of new tumors. Stable disease was defined as < 50% change in tumor volume at 42 days without development of new lesions. Progressive disease (PD) was defined as ≥ 50% increase in tumor volume or development of new tumors at any time. Dogs were reevaluated at 42-day intervals until they had a CR, developed PD, or developed unacceptable adverse effects.

Results

Three dogs had a PR, 4 had stable disease, and 9 had PD. Tumor response could not be assessed in 2 dogs: 1 dog developed grand mal seizures 3 hours after the first dose of cisplatin was given and was euthanatized; the other dog continued to have clinical signs of urinary tract obstruction and was euthanatized 8 days after the first dose of cisplatin. Four dogs developed renal azotemia that was suspected to be secondary to cisplatin nephrotoxicity.

Clinical Implications

The cisplatin dosage was higher than that reported in studies of dogs with transitional cell carcinoma of the bladder. Even with this higher dosage, none of the dogs had a CR, and only 3 of 18 had a PR. A more effective, less toxic treatment for transitional cell carcinoma in dogs is needed. (J Am Vet Med Assoc 1996;209:1588–1591)

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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To measure programmed cell death ligand-1 (PD-L1) mRNA expression in archived primary nodal diffuse large B-cell lymphoma (DLBCL) specimens of dogs and determine whether that expression was associated with progression-free survival time (PFST).

SAMPLE Archived tumoral lymph node specimens from 42 dogs with DLBCL and lymph node specimens from 10 healthy dogs (controls).

PROCEDURES Archived tumoral and control lymph node specimens underwent multiplex qPCR analysis with probes and primers against canine PD-L1 and glyceraldehyde 3-phosphate dehydrogenase (housekeeping gene) to determine PD-L1 mRNA expression. The 2−ΔΔCt method was used to calculate the fold change in PD-L1 expression in DLBCL specimens relative to that in control lymph nodes. Kaplan-Meier and Cox proportional hazard analyses were used to evaluate the association of various tumoral and clinical factors with PFST.

RESULTS The fold change in PD-L1 mRNA expression in DLBCL specimens relative to control specimens ranged from 0.21 to 7.44. Twenty-one of 42 (50%) DLBCL specimens had a PD-L1-fold change > 1, which suggested PD-L1 was overexpressed in those specimens. Median PFST was 249 days for dogs with DLBCL. The PFST was not associated with PD-L1 mRNA expression but was associated with thrombocytopenia at the time of diagnosis (hazard ratio, 2.56; 95% confidence interval, 1.28 to 5.15).

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that tumoral PD-L1 mRNA expression varied among dogs with DLBCL and that PD-L1 MRNA was overexpressed in half the study population. Therefore, anti–PD-L1 therapies may be clinically beneficial for some dogs with DLBCL.

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in American Journal of Veterinary Research

Abstract

Objective—To determine whether use of topical flea and tick products increases the risk of transitional cell carcinoma (TCC) of the urinary bladder in Scottish Terriers.

Design—Case-control study.

Animals—87 adult Scottish Terriers with TCC (cases) and 83 adult Scottish Terriers with other health-related conditions (controls).

Procedure—Owners of study dogs were recruited through private veterinary practices and the Scottish Terrier Club of America. History of exposure to flea and tick products 1 year prior to diagnosis of TCC for case dogs and during a comparable period for control dogs was obtained through a questionnaire. Risk of TCC associated with exposure to flea and tick products was determined by means of univariate and multiple logistic regression analysis.

Results—After adjustment for host factors, Scottish Terriers treated with topical spot-on flea and tick products containing fipronil or imidacloprid did not have an increased risk of TCC, compared with Scottish Terriers that had never been exposed to any flea and tick products. The risk of TCC associated with use of older topical flea and tick products such as shampoos, dips, powders, sprays, and collars could not be evaluated because of the low number of owners in the study population that had used such products.

Conclusions and Clinical Relevance—Results suggest that use of topical spot-on flea and tick products does not increase the risk of TCC in Scottish Terriers. ( J Am Vet Med Assoc 2004;225:389–394)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the effects of vegetable consumption and vitamin supplementation on the risk of developing transitional cell carcinoma (TCC) of the urinary bladder in Scottish Terriers.

Design—Case-control study.

Animals—92 adult Scottish Terriers with TCC (cases) and 83 Scottish Terriers with other conditions (controls).

Procedure—Owners of dogs with TCC completed a questionnaire regarding their dogs' diet and intake of vitamin supplements in the year prior to diagnosis of TCC; owners of control dogs completed the questionnaire for a comparable time period. The risk (odds ratio [OR]) of developing TCC associated with diet and vitamin supplementation was determined by use of logistic regression.

Results—After adjustment for age, weight, neuter status, and coat color, there was an inverse association between consumption of vegetables at least 3 times/wk (OR, 0.30; 95% confidence interval [CI], 0.15 to 0.62) and risk of developing TCC. For individual vegetable types, the risk of developing TCC was inversely associated with consumption of green leafy vegetables (OR, 0.12; 95% CI, 0.01 to 0.97) and yellow-orange vegetables (OR, 0.31; 95% CI, 0.14 to 0.70). Consumption of cruciferous vegetables was not significantly associated with a similar reduction in risk of developing TCC (OR, 0.22; CI, 0.04 to 1.11). The power of the study to detect a 50% reduction in TCC risk associated with daily vitamin supplementation was considered low (25%).

Conclusions and Clinical Relevance—Results suggest that consumption of certain vegetables may prevent or slow the development of TCC in Scottish Terriers. (J Am Vet Med Assoc 2005;227:94–100)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether exposure to lawn or garden chemicals was associated with an increased risk of transitional cell carcinoma (TCC) of the urinary bladder in Scottish Terriers.

Design—Case-control study.

Animals—83 Scottish Terriers with TCC (cases) and 83 Scottish Terriers with other health-related conditions (controls).

Procedure—Owners of study dogs completed a written questionnaire pertaining to exposure to lawn or garden chemicals during the year prior to diagnosis of TCC for case dogs and during a comparable period for control dogs.

Results—The risk of TCC was significantly increased among dogs exposed to lawns or gardens treated with both herbicides and insecticides (odds ratio [OR], 7.19) or with herbicides alone (OR, 3.62), but not among dogs exposed to lawns or gardens treated with insecticides alone (OR, 1.62), compared with dogs exposed to untreated lawns. Exposure to lawns or gardens treated with phenoxy herbicides (OR, 4.42) was associated with an increased risk of TCC, compared with exposure to untreated lawns or gardens, but exposure to lawns or gardens treated with nonphenoxy herbicides (OR, 3.49) was not significantly associated with risk of TCC.

Conclusions and Clinical Relevance—Results suggest that exposure to lawns or gardens treated with herbicides was associated with an increased risk of TCC in Scottish Terriers. Until additional studies are performed to prove or disprove a cause-and-effect relationship, owners of Scottish Terriers should minimize their dogs' access to lawns or gardens treated with phenoxy herbicides. (J Am Vet Med Assoc 2004; 24:1290–1297)

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in Journal of the American Veterinary Medical Association