Can a CBC Test Detect Cancer? What You Need to Know

CBC expands to Complete Blood Count. The CBC test is a type of blood test used to measure different components in your blood. These include haemoglobin, platelets, red blood cells (RBCs), white blood cells (WBCs), etc. ¹

Also called a full blood count test, CBC is a diagnostic method commonly recommended as part of a complete health checkup.

Likewise, the CBC test can help detect different types of diseases, including cancer, anaemia, infections, and several other immunity-related disorders.

CBC is a vital evaluation technique that is particularly beneficial in the detection of blood cancers, such as leukaemia, lymphoma, and multiple myeloma. It is generally recommended along with several other physical and surgical tests and plays a significant role in cancer detection.

Therefore, in this blog, we have answered the question, 'Can CBC test detect cancer?' in a detailed way. From its uses to its limitations, the sections below cover everything you need to know.

Is CBC Included In A Cancer Screening?

Even though a CBC test can help in cancer detection, there are other cancer screening tests that are important for accurate results.

Below, we have made a list of different tests and categorised them according to their type.

Blood tests that can be combined with a CBC test to detect cancer include:

Tumour markers panel
Circulating tumour cell tests
Blood protein tests

Surgical and physical tests that can be combined with a CBC test to detect cancer include:

Physical examination
X-ray (Medical imaging)
CT scan (Computed Tomography)
MRI test (Magnetic Resonance Imaging)
Biopsy ²

Therefore, since the CBC test measures your blood count, it can detect blood cancer precisely. Examples of such blood cancers include lymphoma and leukaemia. Remember that you undergo several other tests with CBC (complete blood count) to get the correct diagnosis. ³

Can CBC Test Detect Cancer?

If you're looking for an answer to the question “Can CBC test detect cancer?”, then here is what you need to know:

The complete blood count test (CBC) enables your doctor to determine the condition of different blood elements, like:

RBCs (red blood cells)
WBCs (white blood cells)
Platelets
Haemoglobin

It helps evaluate the blood cells' size, number, functioning, and overall health. That is why the CBC test is a crucial part of cancer screening. So, yes, CBC can detect some blood cancers.

However, as mentioned before, you must take the CBC test with other cancer screening tests for a thorough diagnosis.

What Happens When You Get Abnormal CBC Results?

Now, let's move on to how a CBC test can detect cancer only by analysing your blood cells. Since CBC provides an overview of the ultimate health of your blood cells, it enables doctors to determine whether you are at risk of certain types of cancer.

Let's walk you through what occurs following a CBC (complete blood count) test to help you understand.

Role of WBC Count In The CBC Test For Cancer

A complete blood count test shows the number of WBCs (white blood cells) in the blood. The white blood cells, or WBCs, help your body fight against several infections and diseases. They are one of the most vital elements of your immune system. The healthier your WBCs are, the better your immunity will function.

The normal WBC counts required for a healthy individual (based on their gender) should be in the following ranges:

For Males: 5,000 - 10,000
For Females: 4,500 - 11,000⁴

If the WBC count goes above 11,000, it is abnormally high. Similarly, if it is less than 4000, the white blood cell count is abnormally low.

Both of these situations are dangerous for your health because they can give rise to several types of cancers. Here is what happens when you have an abnormally low or abnormally high WBC count:

Leukopenia: Low WBC Count

Low white blood cells are indicative of ⁵:

The CBC test for cancer helps analyse whether you have a low white blood cell count. If yes, your doctor can adjust your medication and suggest treatment accordingly.

Most importantly, CBC helps in the timely identification of lymphoma. Lymphoma is a type of cancer that affects your bone marrow and ultimately makes your immune system weaker.

Even though the CBC test can detect cancer, it is crucial to note that it can only assist in determining the number of white blood cells in your blood. It is not enough to provide an accurate cancer diagnosis. For a more precise picture, doctors may recommend additional tests along with CBC:

These tests provide a more detailed view of blood cell development and characteristics, helping doctors confirm or rule out suspicions raised by a CBC.

Are There Any Limitations of CBC In Detecting Solid Tumours?

A complete blood count (CBC) test is informative but not conclusive. If the results are abnormal, further investigation and consultation with healthcare professionals are needed to determine the underlying causes.

Additionally, when CBC results indicate potential health issues, more comprehensive testing is usually required to confirm a diagnosis and develop appropriate treatment plans.

It's also important to consider how personal attributes, such as age, gender, and health history, along with environmental factors like dehydration or recent blood transfusions, can influence CBC outcomes.

So, how can these cancers be detected instead? Tumour Panel Female and Tumour Panel Male are two alternative methods among many that help in the early detection of several types of cancer, including female-specific cancers like breast cancer.

Why Is It Important To Consider Other Blood Tests With CBC For Cancer Screening?

Along with a CBC test for cancer, tumour markers, circulating tumour cell tests, and blood protein tests are equally essential for cancer screening. These can be used in combination with the CBC test to detect cancer. ⁶

Among these, tumour markers are the most significant. That is because it helps your doctor know crucial details such as:

Ultimately, tumour markers help to determine the severity of your disease and make the scope for improvement of the treatment accordingly.⁷

What Types of Cancer Can a CBC Test Detect?

A CBC test can detect cancer-related to the blood. Abnormal results in a CBC can raise suspicion of some blood cancers. Here is an overview of the three major cancer types that a CBC test is suitable for detecting:

1. Leukaemia

When the number of white blood cells that haven't completely matured increases in your blood, leukaemia happens.

2. Lymphoma

CBC can also detect cancer-related to the lymphatic system, called lymphoma. This type of cancer interferes with the body's ability to fight infections and germs ⁹.

3. Multiple Myeloma

Multiple myeloma, or simply myeloma, is a type of blood cancer that negatively affects the bone marrow.

A person may have multiple myeloma if their CBC findings show the following results:

Limitations of CBC Test For Cancer Detection

While CBC can effectively detect any cancer related to the blood (like lymphoma and leukaemia), it is not the best diagnostic method for detecting solid tumours, such as breast and stomach cancer.

At the same time, it is crucial to note that even though the CBC test cannot directly help determine whether a person has breast cancer or stomach cancer, it can still provide insight into their symptoms. Anaemia is a classic example of one such symptom.

Henceforth, as soon as your doctor knows you are suffering from anaemia with the help of a CBC test, they can make further recommendations on what additional tests you must take. Ultimately, it helps in the analysis of the underlying condition.

Apart from these, the CBC test also cannot detect cancer of the lungs and the colon. However, there are other tests that you can take to diagnose these types of cancers early. Examples of such tests include the following:

All in all, the answer to whether a CBC test can detect cancer is somewhat yes. The limitation is it can't detect cancer on its own. It is not the only tool for cancer detection. Combining it with several other physical and surgical examinations is crucial to get more accurate results.