Cancer marker refers to cancer tissues and cells as oncogenes, tumor suppressor genes, cancer genes and other cancer-related genes and their products produced by abnormal expression of biologically active substances. Some specificity of a cancer such as prostate cancer specific antigen (PSA), also for a total of several forms of cancer, such as carcinoembryonic antigen (CEA) and so on. An ideal cancer marker with which features:
What are the characteristics of cancer markers (1) high sensitivity, should be mainly produced by cancer cells, and stable in body fluids or cells detected.
What are the characteristics of cancer markers (2) specificity, does not exist in normal or benign cancer.
(3) may reflect, predict recurrence or progression of malignant cancers.
(4) in the blood, urine, body cavity fluid concentrations reflect the size of cancer, extent, there is no particular performance of clinical cancer recurrence can be detected.
Marker of cancer diagnosis generally can be used to determine the efficacy and monitoring of disease progression. Common cancers such as lung cancer markers are:
(1) nerve specific enolase (NSE): in the past that the NSE is a small cell lung cancer specific antigen, but now found that about 10% – 30% of non-small cell lung cancer with elevated NSE.
(2), carcinoembryonic antigen CEA: an epitope of human embryos acid glycoprotein. 2 / 3 of non-small cell lung cancer and 1 / 3 of patients with small cell lung cancer CEA levels.
(3) CYFRA21.1 (cytokeratin fragment antigen 21.1): It is a very active current research, a new marker for lung cancer, non-small cell lung cancer CYFRA21.1 sensitivity of 52% – 60%, especially squamous cell carcinoma sensitivity of more than 75%.
What are the characteristics of cancer markers (4), lung squamous cell carcinoma squamous cell carcinoma antigen (SCC) increased significantly, but lung cancer, small cell lung cancer also increased. Most cancer markers were not specific, cross-reactivity between each other, occasionally in some benign diseases and acute and chronic inflammation, it can not be used as screening or diagnostic evidence, only as a secondary diagnosis, determine the efficacy of supplementary indicators, some benign diseases such as pneumonia, influenza, etc., CEA may be slightly increased. General 10 – 15 days return to normal, do not worry too much.