Abstract: The invention relates to tumor marker proteins and their preparation from fluids from one or more cancer patients, wherein said fluids are those which collect in a body cavity or space which is naturally occurring or which is the result of cancer or medical intervention for cancer. The invention also relates to preparation of tumor marker proteins from excretions taken from patients with cancer. The tumor marker proteins are useful as immunoassay reagents in the detection of cancer-associated anti-tumor marker autoantibodies.

Abstract: A method of determining the immune response of a mammal to circulating tumour marker proteins is described in which a sample of bodily fluid, for example plasma or serum, is contacted with a panel of two or more distinct tumour marker antigens. The presence of complexes between the tumour marker antigens and any autoantibodies to the antigens present in the sample are detected and provide an indication of an immune response to a circulating tumour marker protein. The method is useful for the diagnosis of cancer, particularly for identifying new or recurrent cancer in an otherwise assymptomatic patient.