Blood tests serve as important tools in early cancer detection, diagnosis and treatment

While there are many different types of cancer, something that virtually all forms have in common is that they can be most successfully treated when diagnosed in their early stages. Of course, diagnostic testing is essential to early detection and treatment. That includes a number of blood tests that can indicate the presence of cancer in the body. Here, we’ll discuss the most commonly used cancer blood tests and how they can help doctors diagnose this pernicious disease.

Do Complete Blood Count (CBC) Tests Detect Cancer?

This common blood test measures the amount and condition of the various types of blood cells in a sample of blood, including red blood cells, white blood cells and platelets.

While it is used for many other purposes, this test can also help in diagnosing some blood cancers, such as leukemia and lymphoma, by detecting abnormal cells in the blood or abnormal amounts of typical cells. It can also be helpful in determining whether a cancer has spread to the bone marrow, as well as monitoring the progress and/or side effects of cancer treatments.

What Are Tumor Marker Blood Tests?

Tumor markers are chemicals made by tumor cells or by the immune system in response to cancer. Various tests can be used to detect tumor markers in the blood, giving your doctor an indication that cancer may be present in the body. Among the most commonly administered tumor marker tests are:

  • Prostate Specific Antigen (PSA) Testing – Commonly used as a screening tool for the early detection of prostate cancer, PSA testing measures levels of a protein produced by prostate gland cells, called prostate-specific antigen, in the blood. Elevated levels of PSA can give your doctor an early indication of the development of prostate cancer. However, it is important to note that a number of benign prostate conditions can also cause PSA levels to rise.
  • Carcinoembryonic Antigen (CEA) Testing – This antigen, while present in a developing fetus, is not normally present in the blood of healthy adults. When detected in the blood by CEA testing, it can indicate the presence of one of several forms of cancer, including cancers of the colon, rectum, pancreas, breast, ovary or lung.
  • AFP (Alpha-Fetoprotein) Testing – While this antigen is found in the blood of healthy pregnant women, since it is produced by fetal development, it is not normally present in adult men or non-pregnant women. When it is detected by AFP testing, it can be an indication of cancers that include liver, testicular or ovarian cancer.
  • Cancer Antigen 125 (CA-125) Testing – This antigen is used as a tumor marker for ovarian cancer. A protein found on the surface of many ovarian cancer cells, blood tests to measure levels of this antigen are used to aid in diagnosing ovarian cancer, monitoring the progress of ovarian cancer treatments and detecting a recurrence of the disease.
  • Cancer Antigen 19-9 (CA 19-9) Testing – This blood test looks for antigens in the bloodstream that are used as markers for pancreatic cancer. It can be used to help diagnose cancer of the pancreas as well as to monitor treatment progress.
  • Cancer Antigen 27.29 (CA 27.29) Testing – The CA 27.29 blood test measures the level of CA 27.29 antigen in the bloodstream, which is an indication of breast cancer. This test is the only blood test that is specific to cancer of the breast, and is used to aid diagnosis, monitor treatment and detect the spread of breast cancer to other parts of the body.
  • Human Chorionic Gonadotropin (hCG) Testing – A well-known indicator of early pregnancy, hCG is also produced by some cancer cells and is considered a tumor marker, helping to detect germ cell cancers in men and non-pregnant women. Germ cell cancers are tumors that develop from an egg or sperm, including testicular and ovarian cancers.
  • Blood Protein Testing – A blood test that looks for certain abnormal immune system proteins (immunoglobulins) in the bloodstream. Blood protein testing is used to detect multiple myeloma, a cancer of the blood.

What Should You Know About Blood Tests for Breast Cancer?

Every year, more than 200,000 women in the U.S. are told they have breast cancer. On the upside, deaths from the disease are declining as research and advances in diagnosis and treatment continue.

The five-year survival rate for women with breast cancer was 75% in 1974. Today, it’s closer to 90%. That’s real progress despite the fact that breast cancer is the second most common cause of cancer death in women and the main cause of cancer death in women ages 40 to 55. Most of us know someone who has, or had, breast cancer.

However, as a media broadcaster was heard to say, cancer is a word, not a sentence, as in death sentence. In fact, today some types of breast cancer are managed conditions like heart disease and diabetes and this important fact remains: most cancers, including breast cancer, are curable if detected early.

What are the signs and symptoms of breast cancer?

While finding a lump in your breast or having one appear on a mammogram doesn’t automatically mean you have cancer, it does indicate there is a need for further evaluation. Other conditions that can cause lumps in the breast include cysts, benign tumors and certain noncancerous disorders.

According to the Mayo Clinic, the most common sign of breast cancer is a lump or thickening in one breast that can be felt. It may be painless, or it may be tender with some associated pain. Many cancerous lumps are firm, with irregular borders and develop in the upper portion of the breast near the armpit. In the early stages of cancer, there may not be other signs or symptoms.

Since even an experienced healthcare provider can’t always tell if a lump is benign or malignant, all lumps and changes to the breast should be examined and evaluated, with a full medical history, physical exam and imaging tests. If further studies are needed, a biopsy may be necessary. Diagnosing breast cancer is generally a step-by-step procedure that can take several days. Many women say the worst part is the waiting and the uncertainty of knowing whether or not they have cancer.

Do men need to be tested for breast cancer?

The answer is yes, though it is uncommon. Only about 1% of all breast cancers occur in males but when it does, it is similar to breast cancer in women.

Men with breast cancer tend to be older and may have the same BRCA gene mutation as women. Sometimes they present with a painless breast mass, nipple retraction, nipple discharge or bleeding but like women, they may have no signs or symptoms. Standard treatment may include a mastectomy and survival rates in men with breast cancer are similar to women.

Risk factors for men include:

  • Family history, especially with hereditary gene mutation
  • Exposure to radiation
  • Infertility
  • Testicular abnormalities
  • Liver problems
  • Sex chromosome abnormalities

Do Blood Tests Help Detect Ovarian Cancer?

The risk of developing ovarian cancer over a woman’s lifetime is 1 in 79, and her risk of death from invasive ovarian cancer is 1 in 109.

What are the tests for ovarian cancer?

Unlike other cancers, such as breast cancer, there are no truly, reliable screening tests for ovarian cancer. However, research into one or more screening methods is ongoing. The most commonly used preliminary tests to look for cancer of the ovaries are:

  • Pelvic exams
  • Transvaginal ultrasounds
  • CA-125 blood tests

During the pelvic exam, the doctor will insert a finger into your vagina while pressing down on your abdomen. The doctor is looking for an enlarged ovary or tenderness over the ovaries. This finding does not necessarily indicate cancer. Such findings can also appear when a woman has a non-cancerous, or benign, cyst on the ovary. Also, ovarian cancer in its early stages can be too small to feel using this method.

You should be aware that PAP smears look for cancer of the cervix and do not test for ovarian cancer. Therefore, paying attention to your body and having regular pelvic exams is extremely important.

Another related and important exam, which should be done on women who are 35 or older, is a rectovaginal exam. Here the doctor will insert a finger in the rectum and the vagina at the same time, again to feel for unusual swelling or tenderness.

For the transvaginal ultrasound, a wand is placed inside the vagina to get close to the ovaries and uterus. Sound waves are then emitted from the wand into the woman’s body. These sound waves then bounce back from organs, such as the ovaries, to produce a picture. In this way, the doctor can “see” the ovary and any mass or cyst that may be within or attached to it. This test will not be able to tell your doctor if any mass seen is indeed cancerous.

The CA-125 blood test is used to detect the level of the protein, CA-125, which is referred to as a “tumor marker.” This test can sometimes be helpful in identifying ovarian cancer because cancer cells in the ovary release this protein into the body. However, there are other conditions not related to ovarian cancer which can cause higher levels of CA-125 in your body. Because of this, women who are not at an increased risk for ovarian cancer or who are not showing symptoms of ovarian cancer often do not get this test.

What are Early Warning Signs of Cancer and Risk Factors?

It may surprise you, but cancer cells lie dormant in all of us. That’s because the body is a living organism that does not produce every single cell totally perfect. When these defective cells begin to multiple uncontrollably, a tumor forms.

About one in four people die of cancer but that means three-fourths of the population will not. So while cancer is a major disease, and one that should never be taken lightly, it doesn’t strike everyone, even those who may be at risk. In addition, many cancers are survivable today, with a growing number of people in remission and even cancer-free. Early detection and following your doctor’s recommendations for regular testing are key.

Frequently Asked Questions About Cancer Screening Blood Tests

What are the general warning signs of cancer?

While any persistent symptom warrants medical attention, watch for these signs and symptoms that could indicate a serious disease, including a malignancy:

  • Unexplained weight loss with sudden loss of appetite that continues despite good nutrition.
  • Persistent low-grade fever.
  • Fatigue that doesn’t go away with rest.
  • Skin changes including sores that won’t heal.
  • Chronic hoarseness or a cough; particularly with trouble swallowing.
  • Unusual bleeding.
  • Unexplained pain.
  • White patches in the mouth.
  • A lump or thickened area that can be felt through the skin.

What are some known risk factors?

Research can’t explain why one person develops cancer and another doesn’t. Nor do we know that having one or more risk factors will result in cancer. But we do know some people are at higher risk due to the following:

  • Tobacco use – including snuff and chewing tobacco. Smokers are more likely than nonsmokers to develop cancer of the lung and other types of cancer.
  • Age – our risks for developing cancer increase as we get older. Most cancers occur after the age of 65.
  • Exposure to radiation, certain chemicals and other toxic substances – ionizing radiation from x-rays, radon gas and other sources can cause cell damage. Exposure to asbestos, benzene, benzidine, nickel and other chemicals in the workplace are also known carcinogens.
  • Some viruses and bacteria – Human papillomavirus (HPV) infection is a cause of cervical cancer and increases the risk for other types of cancer. HIV causes AIDS and pylori bacteria can cause stomach ulcers and cancer in the stomach lining.
  • Hormones – certain types can increase the risk of breast cancer.
  • A family history of cancer – since cancers develop due to mutations in genes, certain cancers and risk factors can be passed from parent to child. Melanoma and breast cancers, for example, occur more often in families with similar gene mutations.
  • Overexposure to sunlight – ultraviolet radiation from the sun, sunlamps and tanning booths causes early aging of the skin and susceptibility to skin cancer.
  • Obesity with poor diet and lack of physical activity – studies suggest that people with a diet high in fat content have an increased risk of colon, uterus and prostate cancer. Lack of physical exercise can also increase the risks.

What cancer screenings are available and what should I consider if I have risk factors?

Routine screening is linked to a decrease in deaths from cervical, breast, colon and skin cancer. The Centers for Disease Control (CDC) estimates that about 90% of colon cancer patients survive five or more years, or can be cured, when colon cancer is caught early through screenings. It is recommended that adults 50 and older get a colonoscopy or other test, especially if there is a family history of colon cancer, polyps or other bowel diseases. Check with your healthcare provider on test types and timing.

Other recommended screenings:

  • Prostate – with blood testing for elevated PSA
  • Ovarian cancer – there is limited screening capability for this type of cancer but a CA-125 blood test (CA-125 is a protein shed into the blood from cancer cells) can help indicate whether there is cancer present as part of a diagnostic workup.
  • Cervix and uterine – have an annual Pap test
  • Breast cancer – the American Cancer Society recommends an annual mammogram for women beginning at age 40. An MRI may be recommended if there is a strong family history of breast cancer.
  • Lung cancer – an annual X-ray is suggested, especially if you are a smoker.
  • Skin cancer – pay close attention to changes on your skin and contact your health provider if you see: moles that grow or change in appearance, spots that bleed, peel or itch and ulcers or sores that won’t heal.


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