Abstract
Welcome to this special issue of JFMS on feline oncology. With cancer affecting an estimated 1 in 6 cats, 1 and being a leading cause of death in our feline patients, recognising and promptly treating the various types of cancer appropriately is a really important skill for veterinarians to acquire.
The word ‘cancer’ used to be equated with the word ‘death’. It is estimated that, in the UK, more than 1 in 3 of us will develop some form of cancer, 2 and therefore most cat owners will have some experience and probably some prejudices about treating their cats. Cancer, of course, is not necessarily a death sentence; an awful lot of tumours can be cured by good surgical practice if diagnosed and treated early enough, and surgery remains the mainstay of veterinary oncological treatment.
My aim in coordinating this selection of reviews has been predominantly to cover common cancers likely to be encountered by general practitioners. Wrapped around the disease-specific reviews is a scene-setting introduction to treating cancer in cats, and an overview of the specific implications of using cytotoxics in our feline companions.
Cause for optimism … Thoracic radiographs from a 2-year-old FeLV-negative Siamese with mediastinal lymphoma, before (left) and 1 month after (right) commencing chemotherapy. Oriental breeds with this presentation seem to have a durable response to chemotherapy
I included the rarer injection site-associated sarcoma for two reasons – firstly, as this is considered an iatrogenic tumour, it could be argued that there is a moral imperative to identify and promptly treat something that we caused; secondly, it allowed me to ask a soft tissue surgeon to give us her slant on treating cancer.
Lymphoma is a label covering a diverse group of tumours arising from lymphatic tissue. Gastrointestinal lymphoma has been reviewed recently in JFMS.3,4 We have, therefore, chosen to focus on another group of lymphomas, those designated as extranodal, which in themselves are becoming a relatively more common presentation as feline leukaemia virus (FeLV) related lymphoma becomes less frequent.
Since the elucidation of the human genome and the explosion of technology that has allowed us to fathom far more what is happening within cells – both normal and neoplastic – there has been a dramatic increase in our understanding of cancer at the molecular level, which has in turn allowed the development of more targeted treatments. These new developments in human medicine have been mirrored in canine medicine with the licensing of receptor tyrosine kinase inhibitors for dogs and have found their way into feline oncology, albeit as unlicensed products. Future cats that suffer from cancer may well benefit from a more accurate diagnosis, with identification of the specific genetic aberrations associated with an individual tumour as a routine. This would allow a targeted treatment to be used that has a better chance of a good outcome, with less potential for side effects.
We, of course, operate in the here and now and I really hope you find these articles an enjoyable and useful resource to help you treat your current patients in the best way.