Use of electrochemotherapy in veterinary oncology patients
Sofia Chichorro Ramos and others, North Downs Specialist Referrals, Bletchingley
Electrochemotherapy (ECT) involves the application of electric pulses while administering an anti-cancer agent, which increases the permeability of cell membranes and allows more of the drug dose to enter the tumour. Results from using the technique in cats and dogs have been promising but there have been no studies to date involving control groups or with lengthy follow-up times. The authors review the evidence from ECT in both veterinary and human patients and assess the advantages and limitations of this technique. They conclude that in soft tissue sarcomas, mast cell tumours and squamous cell carcinomas, ECT has shown favourable outcomes, and that toxicity is both mild and uncommon. Further work is needed to confirm these findings in trials with longer follow-up and larger cohorts as well as in trials directly comparing the outcomes in cases treated using ECT and surgery alone.
Veterinary and Comparative Oncology, 22
Rate of metastasis in canine thyroid cancer patients
Owen Skinner and others, University of Missouri, Columbia
Thyroid tumours are the most common form of endocrine neoplasm in dogs and regional lymph node metastases are frequently found on post-mortem examination. The authors investigated the rate of histopathologically confirmed metastasis in dogs undergoing thyroid carcinoma thyroidectomy and evaluated the effectiveness of immunohistochemistry in identifying lesions that were not visible using haematoxylin and eosin staining. Their findings in 70 dogs showed that cervical lymph node metastasis was uncommon in dogs with follicular carcinoma but it affected most dogs with medullary carcinoma and nearly half of those dogs with mixed follicular/medullary carcinoma. Extirpation of ipsilateral medial retropharyngeal and identifiable deep cervical lymph nodes is recommended with thyroidectomy until further data on metastatic risk becomes available.
Journal of the American Veterinary Medical Association, 262
Toceranib phosphate in treating feline macroscopic mammary adenocarcinoma
Isabel Del Portillo Miguel and others, University of Edinburgh
Mammary tumours in feline patients are frequently malignant and have a high metastatic rate to the regional lymph nodes and lungs. Surgical removal is the preferred first-line treatment for localised tumours, but post-operative adjunctive chemotherapy is often recommended by oncologists. Toceranib phosphate (Palladia; Pfizer) is a tyrosine kinase inhibitor that has been used successfully in treating feline squamous cell carcinomas and mast cell tumours and appears to be well tolerated in this species. The drug was administered to 17 cats with confirmed mammary adenocarcinoma. Clinical benefits were seen in 12 cats: one had a complete response, five had a partial response and six had stable disease. Eight cats showed signs of toxicity, but these effects were generally mild and could be effectively managed with supportive care.
Journal of Feline Medicine and Surgery, 26
Squamous cell carcinomas affecting the external genitalia of male dogs
Pavlos Natsios and others, University of Zurich, Switzerland
Squamous cell carcinomas are less frequently present on the external genitalia of male dogs than other parts of the body, perhaps due to greater levels of melanin pigment in these areas offering a protective effect. The authors examine the records from 15 such cases examined at a university centre between 1994 and 2000. The dogs belonged to various breeds, with a median weight of 28kg. Seven had white and eight had non-white coats. Each patient was treated surgically by scrotal and preputial ablation, penile amputation or scrotal urethrostomy. The surgical outcomes were satisfactory with eight dogs still alive after a median 23-month follow-up. Dogs with poorly differentiated tumours were more likely to experience tumour recurrence and reduced survival times.
Topics in Companion Animal Medicine, 61, 100887
Increasing uptake of radioactive iodine in dogs with thyroid carcinoma
Stephanie Scheemaeker and others, Ghent University, Belgium
Unresectable thyroid tumours in dogs can be effectively treated by administering radioactive iodine-131, which is absorbed preferentially by the cancerous cells. However, the iodine is less able to enter metastatic cells than the primary tumour, and so dogs with secondaries may show an unsatisfactory response to treatment. The authors investigated the effects of administering recombinant thyroid-stimulating hormone on iodine uptake. Tested in a crossover study involving nine client-owned dogs with thyroid carcinoma, the treatment significantly increased tumour radioactive iodine uptake. This effect would appear to improve the efficiency of radioactive iodine treatment in line with the “as low as reasonably achievable” (ALARA) principle intended to minimise the risks of environmental exposure to radioactivity.
Journal of Veterinary Internal Medicine, 38, 2273-3381
Dogs with anal sac adenocarcinoma treated with modified closed anal sacculectomy
Emma Davey and Cassandra Prpich, Colorado Animal Specialty and Emergency, Boulder
Apocrine gland anal sac adenocarcinoma is an epithelial neoplasm responsible for about 2 percent of canine skin tumours and around 17 percent of perianal malignancies. Standard treatment involves surgical excision of the tumour, anal sacculectomy of the affected side(s) and removal of any metastatic regional lymph nodes. The authors applied a modified version of this technique in 47 dogs and compared the findings with those using the conventional approach. This modified closed anal sacculectomy technique resulted in a lower local recurrence rate and a comparable post-operative complication rate. They state that applying this method will likely reduce the need for adjuvant radiation therapy and potentially reduce the number of patients undergoing chemotherapy.
Veterinary Surgery, 53, 973-979
Suspected paraneoplastic syndrome associated with gastric adenocarcinoma in a dog
Albert Thomas and others, Perth Veterinary Specialists, Osborne Park, Western Australia
Antidiuretic hormone (ADH) is important in both osmoregulation and blood volume regulation. Inappropriately high ADH levels may occur in patients with various disease conditions, including babesiosis, aspiration pneumonia, liver disease, etc. The authors describe a case in which a dog with gastric adenocarcinoma produced excessive ADH, as part of a suspected paraneoplastic syndrome. The dog was a five-year-old male Australian Kelpie who presented with chronic vomiting, hyponatraemia, hypokalaemia, hypochloraemia and increased urinary sodium. Computed tomography identified a gastric tumour and histopathology confirmed a pyloric gastric adenocarcinoma. The tumour was surgically removed using a Billroth I procedure and the electrolyte abnormalities rapidly resolved.
Australian Veterinary Journal, 102, 510-513
Surgical treatment of forelimb osteochondroma in a ferret
Alyssa Ungemach and others, North Carolina State University, Raleigh
Ferrets are susceptible to endocrine system neoplasms such as insulinoma and adenoma but reports of musculoskeletal tumours are uncommon in this species. The authors describe one such case, an osteochondroma, consisting of cartilage-capped osseous outgrowths arising from endochondral ossification. The ferret was a one-year-old neutered male which presented with swelling of the left elbow, associated with the cubital joint. The case was referred to a specialist centre where computed tomography examination revealed lesions in the limb and spine consistent with osteochondroma. A left forelimb amputation with total scapulectomy was carried out. Three months post-operatively, the owner reported a return to normal activity with no evidence of neurological signs.
