CANCER MARKERS:

The immune system plays very important roles at different stages of cancer. A weak or deficient immune system may be the primary cause of cancer. A healthy and strong immune system may prevent or help overcome cancer. New immune markers may appear or get exaggerated during cancer and they help in diagnosis as well as monitoring (prognosis) of cancer. The results of such markers should be looked at in conjunction with the history, type and stage of the disease.

What are Cancer Markers?

Cancer markers are different types of protein molecules produced by the immune system as cancer grows and may be detectable even before cancer reaches a detectable size. There are many types of cancer makers and some are more specific to a certain organ than other. The common cancer markers are discussed here:

ALPHA FETOPROTEIN (AFP):

It is a protein normally produced during pregnancy. The levels are raised in various cancers e.g.

1. Liver cancers (hepatocellular)
2. Testicular cancers (non-seminomatous).
3. Some gastrointestinal cancers and normal pregnancy as mentioned above.

CA 15.3:

This is a carcinogenic Antigen. The values are often elevated in patients with:

1. Breast cancers.
2. Certain non-malignant conditions such as cirrhosis, benign diseases of ovaries & breast.

CA 19.9:  are commonly found in gastric/pancreatic or stomach cancer and is recommended along with CEA. 

CA125 and CA 125-11:

This is a widely used marker for various types of cancers. CA 125-11 is the newer and better version. The test is used for diagnosis as well as assessing response to treatment. A decreasing level suggests good response whereas an increasing level may suggest increased growth of tumor or recurrence or spill into the peritoneum. It may be recommended for the following types of cancers:

1. Cancers of the reproductive system including the uterus, fallopian tubes and ovaries.
2. May be elevated in cancer of the pancreas, lungs, breast and colon.
3. It may be normally raised during menstruation, pregnancy or in individuals with ovarian cysts, pericarditis, hepatitis, cirrhosis of the liver or peritonitis and even in 1-2% of healthy individuals.

CARCINOEMBRYONIC ANTIGEN (CEA):

1. It is a screening test for colorectal cancer and may be done in patients with constipation, bleeding, changed bowel habits and other complaints related to bowel.
2. It may also be recommended for other tumors of the gastrointestinal tract including benign as well as malignant tumors.
3.  It can also help detect Medullary thyroid cancer (MTC).

EVP:

This is Ebstein Bar Virus protein which is used as a screening test for nasopharyngeal carcinoma. EBV has a special relation with this cancer. The antibodies to EBV are elevated in nasopharyngeal carcinoma.

DR-70:

It is a collective screening test for13 different cancers. It is highly specific and catches cancer long before you would suspect anything was amiss. Cancers that can be detected by the test are of the lung, colon, breast, stomach, liver, rectum, ovary, cervix, esophagus, thyroid, and pancreas, trophoblastic and malignant lymphoma.

Pylori Probe:

It is newer test which can detect the presence of Helicobacter Pylori in the stomach which is the primary cause of ulcers and a potential cause of stomach cancer. The accuracy of the test is not known.

ADDITIONAL  MARKERS FOR BLADDER CANCER:

Over the past few years, a number of new tests have been devised to aid the diagnosis of bladder cancer. All these tests are done on a sample of urine. These tests include:

1. The bladder-tumor-associated antigen test:  It is a strip test and the results are interpreted by seeing the change in the color of strip which turns yellow if positive and green if negative for cancer. The test is designed to pick a protein which is produced by the bladder tumor.
2. The fibrin/fibrinogen degradation products test: Fibrinogen degradation products may be increased in the urine in the presence of bladder cancer.
3. NMP22^TM assay.The NMP22^TM assay measures specific proteins from the nuclear matrix (cell center). It can detect transitional cell carcinoma (TCC) with a sensitivity of roughly 67%, meaning that 67% of existing TCCs are detected. But, perhaps more importantly, the NMP22^TM assay is able to predict the recurrence of bladder cancer.
4. New protein test could be twice as accurate in detecting bladder cancer according to a report in The Scotsman

PANEL OF MARKERS FOR BREAST CANCER:

1. CA 15.3
2. CA125.
3. DR-70

PANEL OF MARKERS FOR COLON/COLORECTAL CANCER:

1. Carcinoembryonic antigen (CEA)
2. DR-70
3. PreGen-26: it is a new test done on stool sample and is used for patients with hereditary non-polyposis colorectal cancer (HNPCC). There is an 80% life time risk of developing cancer in these patients.

PANEL OF MARKERS FOR LUNG CANCER:

1. CA125
2. DR-70
3. T/Tn antigen

PANEL OF MARKERS FOR OVARIAN AND CERVICAL CANCER: 

1. CA125 levels
2. DR-70
3. Pap Smears/PAPNET

PANEL OF MARKERS FOR PANCREATIC/STOMACH CANCER:

1. CA 19.9
2. DR-70

PANEL OF MARKERS FOR THYROID CANCER:

1. CEA markers can also help detect Medullary thyroid cancer (MTC).
2. DMSA scan for Medullary thyroid cancer (MTC).
3. DR-70

TESTS FOR PROSTATE CANCER:

1. PSA
2. Free PSA (fPSA) test: The test is done on a blood sample and can distinguish cancer from benign prostatic conditions. Free PSA ratios can be used to denote the aggressiveness of the tumor.
3. PSA density test: This test has a better detection rate however it needs to use ultrasound.