Tumor Markers are biological substances like protein that can be produced in high level than normal level in patients with cancer. Tumor markers can be produced in blood, urine or any tissue of the cancer patient. Tumor markers can be produced either by tumor cell or by body cells in response to the tumor.
Tumor markers can be used to detect cancer along with other tests like X-ray. Measurement of tumor markers alone is not sufficient to diagnose cancer because tumor marker levels are increased only in some of the cancer patients. In early stages of cancer the level of tumor markers are not high than the normal. Many of the tumor markers are not specific to the cancer type. That is the level of a particular type of tumor marker can be raised by many types of cancer.
Tumor markers not only for cancer detection but also been used by doctors in deciding the type of appropriate therapy to treat the cancer patients. In many cases the level of tumor marker is proportionate to the level of cancer present in the body. Tumor markers are also used to monitor the response of patient to the cancer therapy. As decreased or normal level of these tumor marker may also indicate the complete cure of cancer from the body of patient.
At present the tumor markers are used to monitor the response of patient to the present cancer therapy and also to check the chances of recurrence of the disease. Research is going on to use these tumor markers in early detection of cancer.
Some Commonly Measured Tumor Markers:
Prostate Specific Antigen:
In all adult males low concentration of prostate specific antigen (PSA) are present, but high level of PSA are found in the patient with prostate cancer conditions like prostatitis, benign prostatic hyperplasia or tumor growth in the prostate gland. Elevated level or higher level of PSA indicates the requirement of other tests to confirm the presence of cancer.
PSA are used in monitoring the patient's response to the cancer treatment and in checking recurrence of the condition after treatment. Increased level of PSA indicates the recurrence of the cancer in already treated patients.
Small level of carcinoembryonic antigen is present in normal healthy persons but elevated level indicates the presence of cancer. Carcinoembryonic antigen is used in monitoring metastatic patient with colorectal cancer, and also to monitor for recurrence of colorectal cancer after treatment.
Elevated level of carcinoembryonic antigen may also indicate the presence of breast cancer, lung cancer, pancreatic cancer, stomach cancer, cervix cancer, ovary cancer or kidney cancer.
Alpha-fetoprotein (AFP) normally produced by a unburned developing fetus, but they are undetectable in healthy adults. Higher level of alpha-fetoprotein indicates the conditions such as primary liver cancer or germ cell cancer of the ovary or testicle.
Human Chorionic Gonadotropin:
Human chorionic gonadotropin (HCG) is normally produced during pregnancy by the placenta. Higher level of human chorionic gonadotropin may indicate the presence of liver cancer, stomach cancer, ovary cancer, pancreatic cancer or lung cancer. HCG are used to monitor the trophoblastic disease treatment and also used in choriocarcinoma screening.
About Author / Additional Info: