British Veterinary Study Group Autumn Meeting
7th November 2010
On 6th and 7th November I attended the annual autumn meeting of the BVDSG.
The theme for the weekend was Oncology and delegates were given the latest information on common skin tumours such as Mast Cell Tumours and Squamous Cell Carcinoma and the rarer ones such as the lymphoid and histiocytic tumours.
One of the most common skin tumours we see is the Mast Cell Tumour and a lot of research has been done on this neoplasm, which can look just about like any other skin tumour. The current textbooks which most vets have are now out of date regarding the management of mast cell tumours. Because this tumour has such a wide ranging array of appearances it is recommend that ALL skin tumours should be examined cytologically. The procedure, called a fine needle aspirate is easy to perform inthe consulting room and the characteristic mast cells are , in the vast majority of cases, easy to identify. Early diagnosis is very important as some Mast Cell Tumours are malignant and aggressive.
The majority of mast cell tumours are benign, but they should be removed and sent off to the lab for histopathological grading and staging should be made by examining draining lymph nodes etc. Some mast cell tumours are so large at the time of diagnosis that they are unable to be removed surgically and there have been some excting developments with new targeted drug therapies. For the last year there has been a drug available from France called Masivet (mastinib) which works best on the 30% cases which have a specific mutation but can work on other cases. A a similar drug, called Palladia (toceranib) has just been released in the UK with promising results. Both drugs are licensed for non-resectable tumours. Annual costs for a Labdrador would be in the region of £4000 with Masivet and around £3600 with Palladia. Treatment is what is termed cytostatic (rather than cytotoxix) so may only work if the drug is continued indefinitely, but there are reported cases where the tumour has not returned when the drug is stopped. Further research on both these new drugs is still ongoing.
Squamous Cell Carcinoma a common tumour seen both in cats and dogs, usually in unpigmented skin and is commonly the result of ultraviolet light damage from the sun, but there is now increasing interest in the role of papillomaviruses in the pathogenesis of these tumours. It is important that cats with white ears/unpigmented noses are kept out of the sun, particularly in the middle of the day.and the same can be said with white dogs such as English Bull Terriers or Dalmations. Owners should also consider use of sun blocks and sun blocking suits available for small children!
