TUMOR MARKERS

Cancer Blood Tests: Lab tests used in cancer diagnosis

Cancer blood tests and other laboratory tests may help your doctor make a cancer diagnosis. Reduce your anxiety by learning about cancer blood tests and how they're used.

Blood tests alone can rarely, if ever, show the presence or absence of cancer. If your doctor suspects you may have cancer, he or she may order certain cancer blood tests or other laboratory tests, such as an analysis of your urine, to help guide the diagnosis. While cancer blood tests generally can't tell whether you have cancer or some other noncancerous condition, they can give your doctor clues about what's going on inside your body.

Because your doctor has ordered cancer blood tests or other laboratory tests to look for signs of cancer doesn't mean that a cancer diagnosis has been made and you have cancer. Find out what your doctor might be looking for when cancer blood tests are done.

What your doctor is looking for

Your doctor may order cancer blood tests or other types of laboratory tests after conducting a physical exam. The signs and symptoms you report may give your doctor clues about what could be wrong. Tests to analyze your blood, urine or body tissues may give your doctor further information about your condition.

Blood and urine samples are analyzed in a lab. If the doctor finds cancer cells, too many or too few cells of a particular type, or abnormal types of cells, or if any of various other substances are detected, it may indicate cancer. For example, if you have leukemia - a blood cancer - cancerous white blood cells can be seen under a microscope. A common blood test called complete blood count (CBC) measures the amount of various types of blood cells in a sample of your blood. CBC may give your doctor an idea of what's causing your signs and symptoms.

Blood and urine samples may also be tested for various substances, called tumor markers, which may indicate cancer. Tumor markers are typically chemicals made by tumor cells, but tumor makers are also produced by some normal cells in your body.

For instance, prostate-specific antigen (PSA) is a tumor marker sometimes used to screen men for prostate cancer, though this is somewhat controversial. Any man who hasn't had his prostate removed has a detectable level of PSA in his blood. An abnormally elevated PSA level may prompt your doctor to recommend further testing for prostate cancer. Another tumor marker is cancer antigen 125 (CA 125), which may be elevated in women with ovarian cancer, though levels can be elevated in people with other types of cancer and with many benign conditions. A high CA 125 result may prompt your doctor to recommend further testing to determine the cause.

What the results mean

Test results must be interpreted carefully because several factors can influence test outcomes, such as variations in your own body or even what you eat. In addition, it's important to remember that noncancerous conditions can sometimes cause abnormal test results. And, in other cases, cancer may be present even though the blood test results are normal.

Your doctor usually uses your test results to determine whether your levels fall within a normal range. Or your doctor may compare your results with those from past tests.

What happens next

Though blood and urine tests can help give your doctor clues, other tests are usually necessary to make the diagnosis. For most forms of cancer, a biopsy - a procedure to obtain a sample of suspicious cells for testing - is usually necessary to make a definitive diagnosis.

In some cases, tumor marker levels are monitored over time. Your doctor may schedule follow-up testing in a few months. Cancer blood markers are most helpful after your cancer diagnosis. Your doctor may use these tests to determine whether your cancer is responding to treatment or whether your cancer is growing.

Discuss your test results with your doctor. Ask your doctor what your results say about your health and what the next steps should be. 

Courtesy of: Mayo Clinic

Understanding Tumor Markers

Tumor markers are substances that can be detected in higher than normal amounts in the blood, urine or body tissues of some people with certain types of cancer. A tumor marker may be produced by the tumor itself or by the body in response to a cancer presence. When diagnosing cancer, blood and pieces of tumor tissue are tested to determine the characteristics of the tumor (aggressiveness, rate of growth and degree of abnormality). Tests for tumor markers should  be used with other tests or x-rays to detect and diagnose some cancers.

Guidelines:

  • Tumor markers may be proteins, antigens or hormones. 

  • Tumor markers tests are not used alone in diagnosis because most markers can be found in elevated levels in people who have benign conditions and because no tumor marker is specific to a particular cancer.

 

  • Not every tumor will cause an elevation in the tumor marker test, especially in the early stages of cancer. 

  • Physicians can use changes in tumor marker levels to follow the course of the disease, to measure the effect of treatment and to check for recurrence. 

  • Certain tumor markers are simply more accurate than others in their sensitivity to detection of cancer. The more sensitive they are, the earlier it is possible to diagnose. 

  • Normal levels differ between people and between laboratories.

Your physician is the best person to consult if you have concerns about your specific test level.

Table: Tumor Markers

Tumor Marker

Primary Cancer Site

Secondary Cancer Site (>50%)

False Positives

Other Benign Diseases Detected

Normal Values

ADH – Antiduretic Hormone

Small cell lung cancer, adenocarcinoma

 

Inappropriate secretion associated w/ Pneumonia

Porphyria

1-5 pg/ml

AFP – Alfa-Feto protein

Liver, germ cell cancer of ovaries & testis

 

Pregnancy

Cirrhosis, Hepatitis, Toxic Liver Injury; Inflammatory Bowel Disease

0-6.4 IU/ml in men & Non-pregnant women

BTA – Bladder Tumor Antigen

Bladder

 

Recent invasive procedure; GUT Infection; Cancer of Kidney, ureters

 

Not detected

CA15-3 : Carbohydrate Antigen 15-3

Breast

Often not elevated in early stages of breast cancer

 

Benign breast & Liver cancer

<31 U/ml

CA19-9

Pancreas, Colorectal

 

 

Pancreatitis, Ulcerative Colitis; Inflammatory Bowel Disease

<33 U/ml

CA125

Ovarian

Breast; Colorectal

Pregnancy, Menstruation

Endometriosis; Ovarian Cysts; Fibroids; Inflammatory Bowel Disease; Cirrhosis; Peritonitis; Pancreatitis

0-35 U/ml

Calcitonin

Thyroid Medullary Carcinoma

Ectopic Calcitonin-producing Tumors (Rare)

 

 

Basal:

< 0.155 ng/ml for men
< 0.105 ng/ml for women

CEA – Carcinoembryonic Antigen

Colon; Lungs

Ulcerative Cancer; Breast; Ovarian

-Cigarette smoking

-About 5% of population has above normal CEA

pancreatitis, hepatitis, COPD, lung infection, inflammatory bowel disease, biliary obstruction

 

< 3 ng/ml in non-smokers

< 5 ng/ml in smokers

Creatin-kinase-BB

 

Breast, ovary, colon, prostate

 

 

 

renal failure, bowel infarction, stroke

 

40-200 u/l in men
35-150 u/l in women

hCG - human chorionic gonadotropin

 

Trophoblastic disease

 

Germ cell tumors

 

Pregnancy, marijuana smoking, testicular failure

duodenal ulcers, cirrhosis, inflammatory bowel disease, benign breast, lung, pancreas, ovary, or GI cancer

> 31 U/ml

 

LDH - Lactic dehydrogenase

Lymphoma, seminoma, acute leukemia, metastatic carcinoma

 

 

hepatitis, myocardial infarction

100-210 u/l

NSE - Neuron-Specific Enolase

Neuroblastoma, small cell lung cancer

 

 

 

< 13 ng/ml

NMP 22

Bladder

 

Recent invasive procedure, Chemotherapy, Infection genitourinary tract, Benign genitourinary disease, renal or bladder stones

 

<10

PAP - Prostatic acid phosphatase

Metastatic cancer of prostate, myeloma, lung cancer, osteogenic sarcoma

 

 

prostatitis, nodular prostatic hypertrophy

0.5-1.9 u/l

 

PSA - Prostate specific antigen

Prostate

 

 

benign prostatic hypertrophy, nodular prostatic hyperplasia, prostatitis

< 4 ng/ml

 

 

TUMOR MARKERS

In alphabetical order:

ADH - Antidiuretic Hormone:

  • PCS: Small cell lung cancer, adenocarcinoma

  • S CS: 0

  • FP: Inappropriate secretion assoc. w/ pneumonia

  • OBDD: porphyria

  • NV = 1-5 pg/ml

AFP - Alpha-Feto Protein:

  • PCS: Liver, germ cell cancer of ovaries or testis

  • FP: Pregnancy

  • OBDD : cirrhosis, hepatitis, toxic liver injury, inflammatory bowel disease

  • NV = 0-6.4 IU/ml - in men and nonpregnant women

CA15-3 - Carbohydrate Antigen 15-3:

  • PCS: Breast

  • SCS: Often not elevated in early stages of breast cancer

  • OBDD: benign breast & liver cancer

  • N = < 31 U/ml

CA19-9:

  • PCS: Pancreas, colorectal

  • OBDD: pancreatitis, ulcerative colitis, inflammatory bowel disease

  • NV = < 33 U/ml

CA125 :

  • PCS: Ovarian

  • SCS: Breast, Colorectal

  • FP: Pregnancy, menstration

  • OBDD: endometriosis, ovarian cysts, fibroids, inflammatory bowel disease, cirrhosis, peritonitis, pancreatitis

  • NV = 0-35 U/ml

Calcitonin

  • PCS: Thyroid medullary carcinoma

  • SCS: Ectopic calcitonin-producing tumors (rare)

  • NV = Basal:

  • MEN: < 0.155 ng/ml

  • WOMEN: < 0.105 ng/ml

CEA - Carcinoembryonic Antigen

  • PCS: Colon, Lung

  • SCS: Ulcerative cancer, Breast, Ovarian

  • FP: Cigarette smoking - About 5% of the population has above normal CEA

  • OBD: pancreatitis, hepatitis, COPD, lung infection, inflammatory bowel disease, biliary obstruction

  • NV =

  • NON-SMOKERS: < 3 ng/ml

  • SMOKERS: < 5 ng/ml

Creatin-Kinase-BB

  • PCS: Breast, ovary, colon, prostate

  • OBDD: renal failure, bowel infarction, stroke

  • NV =

  • MEN: 40-200 u/l

  • WPMEN: 35-150 u/l

hCG - Human Chorionic Gonadotropin

  • PCS: Trophoblastic disease

  • SCS: Germ cell tumors

  • FP: Pregnancy, marijuana smoking, testicular failure

  • OBDD: duodenal ulcers, cirrhosis, inflammatory bowel disease, benign breast, lung, pancreas, ovary, or GI cancer

  • NV = > 31 U/ml

LDH - Lactic Dehydrogenase

  • PCS: Lymphoma, seminoma, acute leukemia, metastatic carcinoma

  • OBDD: hepatitis, myocardial infarction

  • NV = 100-210 u/l

NSE - Neuron-Specific Enolase

  • PCS: Neuroblastoma, small cell lung cancer

  • NV = < 13 ng/ml

PAP - Prostatic Acid Phosphatase

  • PCS: Metastatic cancer of prostate, myeloma, lung cancer, osteogenic sarcoma

  • OBDD: prostatitis, nodular prostatic hypertrophy

  • NV = 0.5-1.9 u/l

PSA - Prostate Specific Antigen

  • PCS: Prostate

  • OBDD: benign prostatic hypertrophy, nodular prostatic hyperplasia, prostatitis

  • NV = < 4 ng/ml

Abbreviations & Legend:

ABBREVIATION GUIDE:

  • ml: milliliter 

  • U: International Unit 

  • ng: nanogram 

  • pg: picogram

  • ug: microgram 

  • u/l: units per liter 

  • <: less than

  • <: less than or equal to [< + underscore below]

  • <] >: greater than

 
LEGEND:
  • Primary Cancer Site = PCS
  • Secondary Cancer Site(>50%) = SCS   
  • False Positives = FP  
  • Other Benign Diseases DETECTED = OBDD 
  • Normal Values = NV