Surgical treatment and outcome of primary rib tumours in cats: eight cases (2016-2023).

OBJECTIVES: To describe the clinical features and oncologic outcome for cats with primary rib tumours. MATERIALS AND METHODS: Medical records for cats with surgically treated primary rib tumours from six veterinary referral centres were reviewed. Signalment, preoperative clinical signs, reconstruction technique, and surgical and oncologic outcome were retrieved from medical records or by telephone interview with owners and/or referring veterinarians. RESULTS: Of the eight cats with primary rib tumours, three had hemangiosarcoma, two had osteosarcoma and one cat each had chondrosarcoma, osteochondroma and osteoma. The size of the primary rib mass ranged from 2 × 2 × 1.6 cm to 9 × 7 × 7.5 cm. Three minor and one major complication developed during the immediate post-operative period. Surgery consisted of thoracic wall resection in all cats. All animals survived the procedure and the median time to discharge was 3 days. The survival time for benign tumours was 150 (case 5) and 466 (case 4) days, while for malignant tumours ranged from 105 to 550 days (cases 1 to 3, cases 6 to 8). CLINICAL SIGNIFICANCE: Hemangiosarcoma and osteosarcoma were the most represented primary rib tumours in this cohort of cats. Wide surgical excision and adjuvant chemotherapy is recommended for cats with hemangiosarcoma and osteosarcoma, but the prognosis remains guarded. Prognosis appears to be fair for the other tumour types.

Hybrid balloon valvuloplasty for management of severe mitral stenosis in four symptomatic, adult dogs.

Four adult dogs weighing <10 kg presented for the evaluation of severe mitral valve stenosis with clinical signs. Owing to the size of the dogs, a hybrid surgical and interventional approach was utilized for balloon valvuloplasty. A left lateral thoracotomy was performed to allow direct entry through the left atrial wall. Transesophageal echocardiography was utilized for the entirety of the procedure in all dogs, and fluoroscopy was additionally used in two dogs. One dog had mild to moderate intra-operative bleeding from the left atrial wall during the procedure, but no other intra-operative complications were observed. No dogs developed a clinically relevant amount of worsened mitral regurgitation. Based on mitral leaflet mobility and transmitral flow profiles, there was perceived improvement in all four dogs. One dog died 6 h after extubation due to respiratory arrest. The remaining dogs survived to discharge and had resolution of clinical signs at home and discontinuation of heart failure medications. One dog died of an unknown cause at five months and another developed atrial fibrillation, and the owners elected to euthanize at ten months after the procedure. One dog continues to do well six months after the procedure as of the time of this writing. Hybrid balloon valvuloplasty can be a viable management option for small breed dogs with severe mitral stenosis exhibiting clinical signs, and both transesophageal echocardiography and fluoroscopy can be used intra-operatively to assist in successful procedural outcomes.

Genome-wide analysis of canine oral malignant melanoma metastasis-associated gene expression.

Oral malignant melanoma (OMM) is the most common canine melanocytic neoplasm. Overlap between the somatic mutation profiles of canine OMM and human mucosal melanomas suggest a shared UV-independent molecular aetiology. In common with human mucosal melanomas, most canine OMM metastasise. There is no reliable means of predicting canine OMM metastasis, and systemic therapies for metastatic disease are largely palliative. Herein, we employed exon microarrays for comparative expression profiling of FFPE biopsies of 18 primary canine OMM that metastasised and 10 primary OMM that did not metastasise. Genes displaying metastasis-associated expression may be targets for anti-metastasis treatments, and biomarkers of OMM metastasis. Reduced expression of CXCL12 in the metastasising OMMs implies that the CXCR4/CXCL12 axis may be involved in OMM metastasis. Increased expression of APOBEC3A in the metastasising OMMs may indicate APOBEC3A-induced double-strand DNA breaks and pro-metastatic hypermutation. DNA double strand breakage triggers the DNA damage response network and two Fanconi anaemia DNA repair pathway members showed elevated expression in the metastasising OMMs. Cross-validation was employed to test a Linear Discriminant Analysis classifier based upon the RT-qPCR-measured expression levels of CXCL12, APOBEC3A and RPL29. Classification accuracies of 94% (metastasising OMMs) and 86% (non-metastasising OMMs) were estimated.

Evaluation of information presented within soft tissue sarcoma histopathology reports in the United States: 2012-2015.

Despite the existence of the American College of Veterinary Pathology guidelines for tumour biopsy specimens, anecdotally the authors' have seen inconsistency of reporting of information on the pathology report for canine soft tissue sarcomas (STSs). If crucial aspects are not reported this can result in slower or impeded patient care. This retrospective study evaluated 255 STS histopathology reports submitted from across the United States. Reports were evaluated by a single observer to assess for information contained in 5 main categories: patient history and signalment, gross and microscopic description, grading, histologic margins and the comments section. Inclusion criteria for histopathology reports included a final diagnosis of STS, having a microscopic description and resulting from the initial surgical resection. The majority of the reports stated the patient signalment (91.2%) and clinical history (90.8%). However, only 64.8% of the reports had a gross description of the specimen. Histologic margin description was present in 229 reports (91.6%), however, only 149 reports (59.6%) stated an objective measurement of these margins. Histologic classification was stated in 50.0% of the reports, while grade was given on 97.2% of the reports. Variability in histopathologic reporting including histologic margin description for resected canine STS was identified. Given surgical treatment is the mainstay for STS and histopathological assessment plays an important role in determination of whether additional surgery, radiation or chemotherapy is needed. Standardization or checklists like the American College of Pathology utilize may be helpful to ensure histopathologic characteristics are reported that may guide further treatment recommendations.

Canine spinal meningiomas and nerve sheath tumours in 34 dogs (2008-2016): Distribution and long-term outcome based upon histopathology and treatment modality.

The purpose of this retrospective, multicentre case series was to describe the outcome following surgery and/or radiation of spinal meningiomas and nerve sheath tumours (NSTs) based upon treatment modality, with a specific aim to evaluate the survival times and time to recurrence following treatment for each histopathological diagnosis. Our hypothesis was that the addition of radiation therapy modalities to treatment will yield longer time to recurrence of clinical signs and survival time. Thirty-four dogs met the inclusion criteria of histopathologically diagnosed extramedullary spinal meningioma or NST. Sixteen extramedullary spinal meningiomas and 18 NSTs were diagnosed. A diagnosis of meningioma was associated with a significantly longer survival time compared with NSTs, with median survival times (MST) of 508 days (95% confidence interval [CI]: 66-881) vs 187 days (95% CI: 76-433; P = .02). Dogs (seven) treated with stereotactic radiation therapy (SRT) for recurrence after surgery alone or SRT alone as their initial treatment gained an additional 125 to 346 days survival time.

Outcome following treatment of soft tissue and visceral extraskeletal osteosarcoma in 33 dogs: 2008-2013.

Extraskeletal osteosarcoma (EOS) is a rare, highly malignant mesenchymal neoplasm arising from viscera or soft tissues characterised by the formation of osteoid in the absence of bone involvement. Owing to the rarity of these neoplasms very little information exists on treatment outcomes. The purpose of this study was to describe the outcome following surgical treatment of non-mammary and non-thyroidal soft tissue and visceral EOS in dogs. Thirty-three dogs were identified; the most common primary tumour site was the spleen. Dogs that had wide or radical tumour excision had longer survival times compared with dogs that had only marginal tumour excision performed [median survival time of 90 days (range: 0-458 days) versus median survival time of 13 days (range: 0-20 days)]. The use of surgery should be considered in the management of dogs with non-mammary and non-thyroidal soft tissue and visceral EOS.

Chemotherapy effectiveness and mortality prediction in surgically treated osteosarcoma dogs: A validation study.

Canine osteosarcoma is the most common bone cancer, and an important cause of mortality and morbidity, in large purebred dogs. Previously we constructed two multivariable models to predict a dog's 5-month or 1-year mortality risk after surgical treatment for osteosarcoma. According to the 5-month model, dogs with a relatively low risk of 5-month mortality benefited most from additional chemotherapy treatment. In the present study, we externally validated these results using an independent cohort study of 794 dogs. External performance of our prediction models showed some disagreement between observed and predicted risk, mean difference: -0.11 (95% confidence interval [95% CI]-0.29; 0.08) for 5-month risk and 0.25 (95%CI 0.10; 0.40) for 1-year mortality risk. After updating the intercept, agreement improved: -0.0004 (95%CI-0.16; 0.16) and -0.002 (95%CI-0.15; 0.15). The chemotherapy by predicted mortality risk interaction (P-value=0.01) showed that the chemotherapy compared to no chemotherapy effectiveness was modified by 5-month mortality risk: dogs with a relatively lower risk of mortality benefited most from additional chemotherapy. Chemotherapy effectiveness on 1-year mortality was not significantly modified by predicted risk (P-value=0.28). In conclusion, this external validation study confirmed that our multivariable risk prediction models can predict a patient's mortality risk and that dogs with a relatively lower risk of 5-month mortality seem to benefit most from chemotherapy.

Stereotactic radiation therapy for treatment of canine intracranial meningiomas.

The objective of this study is to determine the rate of toxicity, median survival time (MST) and prognostic factors in dogs with presumed intracranial meningiomas that were treated with stereotactic radiation therapy (SRT). Patient demographics, neurological history, details of SRT plans and response to treatment (including toxicity and survival times) were examined for potential prognostic factors. Overall MST (MST) due to death for any cause was 561 days. There was a mild to moderate exacerbation of neurological symptoms 3-16 weeks following SRT treatments in 11/30 (36.7%) of dogs. This presumed adverse event was treated with corticosteroids, and improvement was seen in most of these dogs. Death within 6 months of treatment as a result of worsening neurologic signs was seen in 4/30 (13.3%) of dogs. Volume of normal brain that received full dose at a prescription of 8Gy × 3 fractions was predictive of death due to neurological problems within this 6-month period.

Treatment of canine cranial cruciate ligament disease. A survey of ACVS Diplomates and primary care veterinarians.

OBJECTIVE: To describe veterinarians' treatment recommendations and decision-making factors for dogs with cranial cruciate ligament disease (CCLD). METHODS: An online survey of American College of Veterinary Surgeons (ACVS)-Diplomates (surgeon group) and primary care veterinarians (practitioner group) was performed. The survey included questions on treatment recommendations for common case scenarios (small or large breed dog with complete or partial CCLD), treatment decision factors, non-surgical treatment options, and actual treatment, if any, provided for a client-owned dog as well as one owned by their family or close friend. RESULTS: The response rate was 42% for the surgeon group (n = 305/723) and four percent for the practitioner group (n = 1145/ 27,771). Extracapsular stabilization (ES) was the most common treatment recommendation for CCLD in small (9.1 kg) breed dogs amongst surgeons and practitioners. Tibial plateau levelling osteotomy (TPLO) was the most common treatment recommendation for CCLD in large (27.2 kg) breed dogs amongst both groups. The two most important treatment decision factors were dog size (78% of practitioners, 69% of surgeons) and activity level (63% of practitioners, 52% of surgeons). The most common treatment provided for a dog of their own or close relation in the surgeon group was TPLO (64%) followed by ES (15%), whereas in the practitioner group it was ES (38%) followed by TPLO (30%). CLINICAL SIGNIFICANCE: Extracapsular stabilization and TPLO are the most commonly employed surgical procedures in the surveyed population; dog size and activity level (but not age) are the major factors influencing treatment decisions.

Bi-institutional retrospective cohort study evaluating the incidence of osteosarcoma following tibial plateau levelling osteotomy (2000-2009).

OBJECTIVES: To evaluate the incidence and risk factors for occurrence of osteosarcoma (OSA) following tibial plateau levelling osteotomy (TPLO). METHODS: Medical records of client-owned dogs that underwent consecutive TPLO procedures at two institutions were retrospectively reviewed. Referring veterinarians and owners were contacted for follow-up. Each institutional cohort was assessed separately, and the incidence density rate and median time to occurrence of OSA at the TPLO site and at other sites were calculated. Marginal Cox regression was used to calculate hazard ratios and 95% confidence intervals for potential risk factors for occurrence of OSA. RESULTS: There were 472 CLINIC A (Colorado State University Veterinary Teaching Hospital) and 1992 CLINIC B (SAGE Centers for Veterinary Specialty and Emergency Care) TPLO cases with over one year of follow-up available. There were five and six dogs within the cohorts that developed OSA at the site of TPLO, and seven and 22 dogs that developed OSA at other anatomical sites, respectively. The incidence density rates of OSA at the TPLO site were 30.4 and 10.2 per 10,000 dog-years at risk, and other sites were 42.6 and 37.5 per 10,000 dog-years at risk. The median time to occurrence of OSA of TPLO site OSA was 4.6 and 4.4 years, which was longer than that of other site OSA of 2.9 and 3.4 years. CLINICAL SIGNIFICANCE: There is a low incidence of OSA following TPLO surgery. The longer time to occurrence for TPLO site OSA is similar to that for fracture-associated sarcoma, and could indicate a similar underlying pathophysiology rather than spontaneous OSA occurrence.

Comparison of carboplatin and doxorubicin-based chemotherapy protocols in 470 dogs after amputation for treatment of appendicular osteosarcoma.

BACKGROUND: Many chemotherapy protocols have been reported for treatment of canine appendicular osteosarcoma (OSA), but outcome comparisons in a single population are lacking. OBJECTIVE: To evaluate the effects of protocol and dose intensity (DI) on treatment outcomes for carboplatin and doxorubicin-based chemotherapy protocols. ANIMALS: Four hundred and seventy dogs with appendicular OSA. METHODS: A retrospective cohort study was performed comprising consecutive dogs treated (1997-2012) with amputation followed by 1 of 5 chemotherapy protocols: carboplatin 300 mg/m(2) IV q21d for 4 or 6 cycles (CARBO6), doxorubicin 30 mg/m(2) IV q14d or q21d for 5 cycles, and alternating carboplatin 300 mg/m(2) IV and doxorubicin 30 mg/m(2) IV q21d for 3 cycles. Adverse events (AE) and DI were evaluated. Kaplan-Meier survival curves and Cox proportional hazards regression were used to compare disease-free interval (DFI) and survival time (ST) among protocols. RESULTS: The overall median DFI and ST were 291 days and 284 days, respectively. A lower proportion of dogs prescribed CARBO6 experienced AEs compared to other protocols (48.4% versus 60.8-75.8%; P = .001). DI was not associated with development of metastases or death. After adjustment for baseline characteristics and prognostic factors, none of the protocols provided a significant reduction in risk of development of metastases or death. CONCLUSIONS AND CLINICAL IMPORTANCE: Although choice of protocol did not result in significant differences in DFI or ST, the CARBO6 protocol resulted in a lower proportion of dogs experiencing AEs, which could be advantageous in maintaining high quality of life during treatment. DI was not a prognostic indicator in this study.

Haemangiosarcoma in the uterine remnant of a spayed female dog.

A 11-year-old, female, spayed greyhound was presented with a haemorrhagic discharge from the vulva. Clinical examination, vaginoscopy and a computed tomography scan showed an irregular egg-sized mass in the region of the cervix and uterine stump. An endoscopic grab biopsy (incisional) suggested a malignant mesenchymal tumour. Following this, surgical excision of the cranial vagina, cervix and the uterine remnant was performed. The final diagnosis of haemangiosarcoma was based on histological examination of the larger excisional biopsy specimen and was confirmed by positive immunolabelling of the neoplastic endothelial cells for the von Willebrand factor.