Lili Duda, VMD
Last Modified: July 28, 2002
Dear OncoLink "Ask The Experts,"
Can you please explain the Wisconsin Protocol? I understand it to be the most effective treatment for canine lymphoma.
Lili Duda, VMD, Section Editor of the OncoLink Veterinary Oncology Menu, responds:
The most effective protocols for canine lymphoma combine several drugs, each of which has individual activity against the malignant lymphocytes. The drugs that are included in the Wisconsin Protocol, and most protocols for canine lymphoma are: vincristine (Oncovin), cyclophosphamide (Cytoxan), L-asparaginase (Elspar), doxorubicin (Adriamycin), and prednisone. This protocol also includes small amounts of methotrexate and chlorambucil, which are a little less common, but still considered standard drugs for lymphoma.
The theory behind combining drugs is that there are many subpopulations of cancer cells, and some of the populations will be resistant to drugs a and b, but sensitive to c, others will be sensitive to c, but not a or b, etc. In addition, some drugs act synergistically, so that the effectiveness of two drugs together exceeds that of the simple sum of each drug individually. There are a variety of different ways to combine drugs, and there are many effective combinations that have been published and/or that are routinely used by different veterinary hospitals. Any protocol has to balance the chance of working effectively against the cancer with the side effects that the chemotherapy drugs are going to cause. Once a patient is started on a protocol, individual drug dosages might have to be modified or even eliminated to suit the particular sensitivity of the patient and the effectiveness of that particular drug on the cancer. This is why it is beneficial to have a board-certified oncologist who has large amounts of experience with these drugs oversee treatment of lymphoma.