Anti-
tumor antibodies have potential as
cancer biomarkers. There is relatively limited identification of anti-
tumor antibodies in response to
ovarian cancer, compared with studies for other
cancers. There is also very limited information on the prevalence of anti-
tumor antibodies among
ovarian cancer patients. Although most anti-
tumor antibodies react with
antigens common to both
tumor and normal tissue, the anti-
tumor response tends to be confined to individuals with
ovarian cancer, similar to other
cancers.
Antibodies to HOXA7, a
differentiation antigen, have the highest reported prevalence in
ovarian cancer (67%).
Antibodies to other ubiquitous
antigens including NY-ESO-1,
Ep-CAM (
epithelial cell adhesion molecule), HSP-90 (
heat shock protein 90), and mutated p53 have been identified in
ovarian cancer. Anti-
tumor antibody specificity reflects the heterogeneity of
antigen expression in
tumors. Tests based on panels of a combination of anti-
tumor antibodies may be more predictive for
ovarian cancer, as no single specificity accounts for ovarian
tumors. In addition to characterization of anti-
tumor antibodies as diagnostic markers, study of anti-
tumor antibodies is likely to provide insights into mechanisms of
tumor development. There is evidence of
antibodies to
tumor antigens and of activated T cells, suggesting immune recognition of
tumor antigens occurred. Nonetheless, as
tumors are not 'rejected', it is likely that there are alterations in the immune system. The basis for
tumor growth in the face of immune activity remains to be determined.