GRH Oncology

  This month, Highcroft Veterinary Referrals oncology specialist Owen Davies continues his advice on how to deal with a canine mast cell tumour, beginning with how to stage mast cell tumours.

Abdominal masses are a common presentation in feline patients, and clinical signs commonly include weight loss, inappetence, vomiting and diarrhoea. The first step in investigation is to consider the likely differential diagnoses and obtain base line haematology and biochemistry to assess for red or white blood cell changes. Investigation of the mass should include abdominal ultrasound to confirm organ of origin, and needle aspirates or trucut biopsy. Ultrasound may give a good indication of the likelihood of successful resection and guide the decision to proceed with additional staging or surgery. The most common abdominal mass in cats is intestinal lymphoma, staging should include testing for FIV/FeLV, and thoracic radiographs if the budget permits. As lymphoma is a systemic disease, chemotherapy is indicated, regardless of staging and surgical intervention. In some patients, however, it is of benefit to excise the mass prior to chemotherapy, in the case of obstruction for example. Other intestinal tumours in felines include carcinoma, mast cell tumour and sarcoma. Abdominal masses may also arise from mesenteric lymph nodes and other organs such as liver, spleen pancreas, bladder or adrenal gland. This session uses a case-based approach to discuss differentials for and investigation of feline abdominal masses.

Disease free intervals (DFI) of 252 days are achieved with CHOP protocols and of 147 days with short COP type. Median survival times (MST) in DLBCL are independent of the induction protocol as long as rescue therapy including doxorubicin is used at relapse. Peripheral T-cell LSAs and lymphoblastic T-cell LSAs are often doxorubicin resistant; with alkylating agent-based protocols like MOPP, LOPP o VELCAP-TSC remission times (175-200 days) are longer than with CHOP. Indolent T-zone LSAs have a favourable prognosis with TSM ranging from 21.2 to 33.5 months without therapy or with chlorambucil and prednisolone. This webinar is provided by BSAVA Education Partner IDEXX. A collection of IDEXX ‘topic of the month’ webinars is available here.

Mammary tumours are the most common type of neoplasia in entire female dogs, representing approximately 50% of all tumours reported, although recently quoted to be as high as 70% of all cancer types. This chapter deals with canine mammary tumours; feline mammary tumours.