Abstract
The repertoires of serum autoantibodies differ between healthy people and cancer patients. While in healthy individuals these autoantibodies are directed against a limited number of self-proteins, in cancer patients the antibody repertoires are much further expanded with a wider range of reactivities against other proteins. Although cancer patients clearly mount humoral immune responses, they are not very effective in preventing the progression of the disease. However, the implication from the presence of these new and abnormal antibody specificities relates to their potential as novel tools for early detection before clinical manifestations. Proteomics technologies, with their unique ability to identify both tumor antigens and their cognate serum autoantibodies, hold great promise in facilitating the development of early detection kits and possibly also as conduits for the isolation of tumor antigens for immunotherapy.