Because radiation and chemo is an unproven modality of treatment for treating soft tissue sarcoma. Clients should avoid taking the advise of any veterinarian who promotes, in the market place, that VAS cats need Chemo or radiation. Clients who have feline or canine vaccine caused soft tissue sarcoma who wish to try chemo or radiation should discuss their situation with a knowledgeable veterinarian who has no commercial interest in making a profit from radiation and chemo soft tissue sarcoma treatment.
The use of this modality of treatment in cats, dogs and humans should be restricted to appropriate research settings.
see
calls for a study that shows chemo and radiation work for VAS
http://evidencebasedvet.com/forum/viewtopic.php?t=128