Tumor markers
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.
| COMMON TUMOR MARKERS | ||
|---|---|---|
| Tumor Marker | Corresponding | Cancer Reliability |
| alpha-fetoprotein (AFP) | LIVER CANCER (hepatocellular cancer); some ovarian cancers; some testicular cancers | moderate for diagnosis |
| Bence Jones protein | MULTIPLE MYELOMA | effective for diagnosis effective for monitoring treatment |
| beta-2 microglobulin (B2M) | multiple myeloma; some lymphomas | questionable for diagnosis effective for monitoring treatment |
| bladder tumor antigen (BTA) | BLADDER CANCER | moderate for diagnosis effective for monitoring treatment |
| CA-27.29 | BREAST CANCER | unreliable for diagnosis in early stages; moderate for diagnosis in metastatic disease effective for RECURRENCE elevation possible in women who do not have cancer |
| CA-72-4 | OVARIAN CANCER; STOMACH CANCER; PANCREATIC CANCER; COLORECTAL CANCER | unreliable for diagnosis |
| CA-125 | ovarian cancer | unreliable 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-5-3 | breast cancer | unreliable for diagnosis in early stages; moderate for diagnosis in metastatic disease effective for recurrence elevation possible in women who do not have cancer |
| CA-9-9 | pancreatic cancer | moderately reliable for diagnosis |
| CALCITONIN | medullary THYROID CANCER | effective for diagnosis |
| CARCINOEMBRYONIC ANTIGEN (CEA) | colorectal cancer; LUNG CANCER; breast cancer | unreliable for diagnosis effective for recurrence elevated in numerous noncancerous health conditions elevated in people who smoke |
| chromogranin A | neuroendocrine cancers | moderate for diagnosis |
| HER-2/neu | breast cancer | unreliable for diagnosis moderate for monitoring treatment |
| human chorionic gonadotropin (hCG) | gestational trophoblastic neoplasia (GTN); TESTICULAR CANCER; ovarian cancer | moderate for diagnosis effective for monitoring treatment |
| M-protein | multiple myeloma | effective 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 cancer | effective for diagnosis effective for monitoring treatment elevatedin BENIGN PROSTATIC HYPERPLASIA (BPH) |
See also CANCER PREVENTION; DIAGNOSING CANCER; ONCOGENES; TUMOR SUPPRESSOR GENES.
