Abstract
New diseases and syndromes appear intermittently in all species and it may be some time before their aetiology is identified. Although the feline leukaemia complex had been recognized for a long time, it was only in the 1970s that relationship between disease and the retrovirus FeLV was established. The associated research paved the way to a more rapid identification of HIV as a cause of AIDS in man. With other diseases the causality may be less strong; BSE is linked to new variant CJD but there are still major questions. For some syndromes the aetiology is still unclear—many will remember the epidemic of the feline dysautonomia syndrome in the early 1980s—what was the cause and why did it suddenly disappear—maybe one day the truth will come out!
In 1991, a letter to the Journal of the American Veterinary Medicine Association from Hendrick and Goldschmidt drew attention to an increasing incidence of fibrosarcoma in cats. They and others also noted that this tumour had an apparent predilection for sites routinely used for vaccination. In itself the tumour type was not new—historically fibrosarcomas account for between 12 and 25% of all feline skin tumours, but with a relatively low incidence overall. These ‘traditional’ fibrosarcomas most commonly affect the limbs but also occur elsewhere. ‘New-variant’ fibrosarcoma has several distinguishing features: its predilection for an intra-scapular site, a more malignant histological appearance, a more aggressive biological behaviour and a very high recurrence rate despite multi-modality therapy. This syndrome, vaccine-associated feline sarcoma, is now well recognized in the USA and is the subject of a large collaborative study under the auspices of the Vaccine-Associated Feline Sarcoma Task Force * , a joint effort of the American Association of Feline Practitioners, American Animal Hospital Association, American Veterinary Medical Association, and Veterinary Cancer Society. The paper by Dennis Macy in this issue (pp. 15–21) gives an excellent up to date overview of the subject as seen in the USA.
So what is the situation outside the USA? It is likely that this condition does occur in Britain as one of the implicated vaccine types is becoming more widely used. Indeed, all of us in referral institutes involved with tumours either as clinicians or as pathologists will have seen several cases that can be fitted into this syndrome. The reported incidence of this problem in the USA is low, between 1 and 10 per 10 000 vaccines administered and therefore the absolute number of cases per annum that could occur in the UK will be relatively small. Only time and epidemiological studies will define the true UK incidence. However, in the meantime, this aggressive tumour needs early and aggressive treatment to achieve a cure and referral to a specialist centre is recommended at the outset.
The Vaccine-Associated Feline Sarcoma Task Force (VAFSTF) is coordinating research in the USA in the areas of epidemiology, aetiology, and treatment. It also recognized the great potential for the vaccine-associated sarcoma to become a public relations disaster for the profession. With that in mind, the VAFSTF established a fourth objective of providing reliable education for the profession and the public. In his paper, Dr Macy reviews the epidemiological evidence, the possible aetiology, the recommendations by the VAFSTF regarding vaccination policy and sites and the treatment of this tumour (pp. 15–21). In addition to Dr Macy's review, the VAFSTF web site is worth visiting not just for an update of the research but also for its owner-advice sheet which, though American biased, covers the important issues.
