Auto-antibodies in breast cancer: a new diagnostic tool?
Session type: Parallel sessions
University of Nottingham, UK
Measurement of cancer associated antigens (eg CA15-3, CA125, CEA) in serum are essentially markers of disease bulk and as such are not useful for screening or detection of early disease. New approaches based on amplification of the early carcinogenesis signal are required to facilitate detection of cancer at a stage before the tumour has spread. The immune system identifies the presence of a cancer and through the humoral response provides an in-vivo amplification signal which is inherently specific since the body does not normally produce autoantibodies to normal antigens.
However a substantial problem to the clinical utility of autoantibodies lies in the heterogeneity of most solid tumours which means that no one antigen is immunodominant. Measuring autoantibodies to only one cancer associated antigen is therefore unlikely to be sensitive enough to make this approach useful as a screening test. One the other hand measuring autoantibodies to multiple antigens is technical challenging, not to mention more expensive, since the requirements for specificity using a panel approach are greater than measuring only one analyte.
Autoantibodies have been detected to different types of cancer and have been reported to be detectable up to 4 years before mammography for breast cancer and 5 years before screening CT for lung cancer. Recent work has reported that 40% of early stage lung cancers are detectable (with a 90% specificity) using a panel of autoantibodies. The panel identified small cell (SCLC) and non-small cell lung cancers (NSCLCs) equally and also picked up both early and late stage disease and all types if NSCLCs. Work is ongoing trying to identify a different panel of antigens which will be useful in the earlier detection of breast cancer.
Declaration of competing interest for John Robertson: John Robertson is the founder and shareholder in a University of Nottingham spinout company, Oncimmune, which has developed autoantibody technology arising from academic research.