What are tumor markers – definition

Molecules, often proteins, cancer cells and some other cells produce. Tumor molecules appear in the BLOOD or in the URINE, which makes it possible to measure their concentrations. Elevated levels of certain tumor markers indicate the need for further evaluation to determine whether a cancer is present. However, most tumor markers are not in themselves conclusive for specific types of cancer, even though they may occur in certain cancers as they can occur in numerous benign (noncancerous) conditions.

As well, different types of cancer may generate elevations in a particular tumor marker, so elevated concentrations of the marker do not provide information of specific diagnostic value. Oncologists must evaluate tumor marker levels in the context of other clinical findings. Because so many factors influence tumor markers, oncologists disagree as to their usefulness, especially for screening and diagnostic purposes.

Some tumor markers are more useful for monitoring the effectiveness of treatment, because the oncologist can track the fall and rise of the marker’s level in the blood circulation. However, tumor markers may rise with successful CHEMOTHERAPY because the dying cancer cells release high quantities of proteins into the blood. After successful treatment, monitoring tumor marker levels may provide early evidence of RECURRENCE should it develop.

Types of Tumor Markers – table

COMMON TUMOR MARKERS
Tumor MarkerCorrespondingCancer Reliability
alpha-fetoprotein (AFP)LIVER CANCER(hepatocellular cancer); some ovarian cancers; some testicular cancersmoderate for diagnosis
Bence Jones proteinMULTIPLE MYELOMAeffective for diagnosis
effective for monitoring treatment
beta-2 microglobulin (B2M)multiple myeloma; some lymphomasquestionable for diagnosis
effective for monitoring treatment
bladder tumor antigen (BTA)BLADDER CANCERmoderate for diagnosis
effective for monitoring treatment
CA-27.29BREAST CANCERunreliable for diagnosis in early stages; moderate for diagnosis in metastatic disease
effective for RECURRENCE
elevation possible in women who do not have cancer
CA-72-4OVARIAN CANCERSTOMACH CANCERPANCREATIC CANCER; COLORECTAL CANCERunreliable for diagnosis
CA-125ovarian cancerunreliable for diagnosis
may be elevated in women who have previously had cancer and are currently cancer free
elevated in endometriosis and benign OVARIAN CYST
CA-5-3breast cancerunreliable for diagnosis in early stages; moderate for diagnosis in metastatic disease
effective for recurrence
elevation possible in women who do not have cancer
CA-9-9pancreatic cancermoderately reliable for diagnosis
CALCITONINmedullary THYROID CANCEReffective for diagnosis
CARCINOEMBRYONIC ANTIGEN (CEA)colorectal cancerLUNG CANCER; breast cancerunreliable for diagnosis
effective for recurrence
elevated in numerous noncancerous health conditions
elevated in people who smoke
chromogranin Aneuroendocrine cancersmoderate for diagnosis
HER-2/neu breast cancerunreliable for diagnosis moderate for monitoring treatment
human chorionic gonadotropin (hCG)gestational trophoblastic neoplasia (GTN); TESTICULAR CANCER; ovarian cancermoderate for diagnosis
effective for monitoring treatment
M-proteinmultiple myelomaeffective for diagnosis
effective for monitoring treatment
NEURON-specific enolase (NSE)small-cell lung cancer (SCLC)modest for diagnosis
moderate for monitoring treatment
PROSTATE-SPECIFIC ANTIGEN (PSA)prostate cancereffective for diagnosis
effective for monitoring treatment
elevatedin BENIGN PROSTATIC HYPERPLASIA (BPH)

See also CANCER PREVENTIONDIAGNOSING CANCERONCOGENESTUMOR SUPPRESSOR GENES.

Tumor markers – definition and types
5 (100%) 1 vote

About The Author

Leave a Reply

Your email address will not be published. Required fields are marked *