Blood Tests for Cancer Detection: What They Can and Can’t Tell You

Why blood tests are used in Cancer diagnosis

Blood is one of the most versatile sources of health information in the body. It flows through every organ and tissue, carrying several nutrients, hormones, proteins, waste products, and even genetic fragments as well. When something ‘abnormal’ like cancer is happening in the body, it often leaves detectable signs in the body.

In most cases, doctors use these tests for three major reasons in cancer care:

• To detect signs that cancer may present 
• To determine how well organs are functioning
• To understand any known cancer before, during or after cancer treatment

These tests can help to guide decisions long before imaging or biopsies come into play. However, these are never used as the only diagnostic tools confirming the cancer.

What blood tests can’t tell about Cancer

Performing only blood tests has significant limitations in cancer diagnosis. Misunderstanding these limitations can lead to unnecessary fear or misplaced confidence in people with suspicion of cancer. 

Blood tests can’t only diagnose cancer on their own

This is the most important part of cancer diagnosis, because you can’t verify cancer diagnosis with test results. 

Even if a test results shows:

• An increased tumor markers, 
• Abnormal organ activities 
• Suspicious DNA fragments

These won’t only prove cancer is present, there are some of the non-cancerous conditions such as infections, stress, pregnancy, liver disease, inflammation, or benign growths, which can cause abnormal results. 

A definitive cancer diagnosis always requires:

• Physical examination
• Complete imaging (MRI, CT, PET or Ultrasound)
• A tissue biopsy

These tests can trigger further investigation but can’t confirm the cancer alone.

A blood tests can’t show the Exact Location of Cancer

Even blood cancer can predict the likelihood of cancer in a patient. But unfortunately, it can’t tell the oncologist about:

• Where the tumor is located
• The size of the tumor
• Whether it has spread in the bodies
• Stage of the cancer

All of this information can be confirmed through further tests and examinations in patients.

It can’t Detect all cancer types

Not all types of cancer release a particular biomarker into the bloodstream. There are types of cancers in the initial stages which produce little to no detectable symptoms.

These tests usually struggle to identify:

• Early-stage cancer
• Small, slow-growing tumor
• Types of breast, lung, and gastrointestinal cancers
• Some lymphomas and sarcomas

This often means a normal blood test does not guarantee that someone is or is not cancer-free!

Blood tests results can’t differentiate between Benign and Malignant Tumors

Here’s how:

• PSA can increase due to a prostate infection or enlargement, not just cancer.
• CA-125 can increase during the menstruation period, pregnancy, or pelvic inflammation.
• AFP can also increase in non-cancers
• These tests suggest an abnormal activity but can’t determine whether a growth is cancerous.

How to use these tests wisely

Performing these tests on suspected cancer patients has both strengths and limitations, and it's important to consider it as part of a broader health strategy rather than a standalone screening test. 

Talk to your healthcare professional

If you are worried about cancer or have a family history of cancer, then speak to a physician who you can recommend this:

• Appropriate cancer screening tests
• Genetic counseling
• Risk assessments
• Lifestyle changes
• Preventive steps

Do not panic over isolated and abnormal test results. There are many factors that are unrelated to cancer, and they can influence blood test values. There is follow-up testing, which is usually required to interpret results correctly.

Consult Today

Performing blood tests has increasingly become a valuable part of modern cancer care. It offers valuable insights about cancer, which can guide early investigation, support cancer diagnosis, and monitor cancer treatments. These tests help oncologists and alert them to any unusual activity and reveal how well organs are functioning. 

At Oncare, we offer premium-quality cancer treatments, including advanced cancer surgeries at an affordable price range with an experienced cancer specialist consultation.

If you or any loved ones of yours are diagnosed with cancer, then visit Oncare Cancer Center and book an appointment with our experienced cancer specialist today! Get an estimated cost of your cancer treatment today!