Antibodies to CK8 (e.g. CAM 5.2) can be used to differentiate
lobular carcinoma of the breast from ductal carcinoma of the
breast. CAM 5.2, an antibody that reacts with an
epitope found on both CK8 and CK18, is used in
immunohistochemistry to demonstrate certain forms of cancer. In normal tissue, it reacts mainly with secretory
epithelia, but not with squamous epithelium, such as that found in the skin, cervix, and esophagus. However, it also reacts with a range of malignant cells, including those derived from secretory epithelia, but also some squamous
carcinomata, such as
spindle cell carcinoma. It is considered useful in identifying microscopic
metastases of breast carcinoma in lymph nodes, and in distinguishing
Paget's disease from
melanoma. It also reacts with
neuroendocrine tumors. Keratin 8 is often used together with keratin 18 and
keratin 19 to differentiate cells of epithelial origin from hematopoietic cells in tests that enumerate
circulating tumor cells in blood. ==Interactions==