Do Routine Blood Tests Detect Cancer?

Erica Kahn
Erica Kahn23 Aug 2022

Routine blood work can detect early signs of cancers, particularly blood cancers such as leukemia and lymphoma. Routine blood tests are recommended for healthy individuals. They can also give insight into organ function, diet, metabolism, and even detect signs of cancer. Four types of blood tests detect cancer, as explained in this article.  

Purpose of Routine Blood Work 

Routine blood work refers to blood tests ordered by your doctor as part of your yearly physical. They are used to screen for a range of health conditions, helping you make informed diet, lifestyle, and fitness choices. Routine blood work can also detect illness before symptoms arise. A routine complete blood count test (CBC) is also commonly referred to as routine blood work. 

Factors That Influence Recommended Blood Tests

Not everyone is recommended the same blood tests. Your family history, age, sex, personal risk factors, and current health status influence the frequency and type of blood tests a doctor might recommend. Your doctor will use this information to help figure out what tests will benefit your health.

Which Blood Tests Detect Cancer?

Blood work that tests for cancer falls into four general categories:

  1. Complete blood count (CBC): helps diagnose leukemia and lymphoma or if cancer has spread to the bone marrow.
  2. Blood protein testing / Serum Protein Electrophoresis (SPEP): helps detect abnormal proteins found in myeloma and monitors how well treatment is working.
  3. Tumor marker tests: helps detect signs of liver, thyroid, ovarian, breast, colorectal, lung, stomach, pancreatic, and testicular cancer.
  4. Circulating tumor cell tests: helps monitor breast, prostate, and colorectal cancers in case they are spreading, but the technology is still in development.

Information Gained from Blood Tests for Cancer

Blood testing is one of the many tools that doctors use to diagnose and manage cancer. Blood tests provide information about:

  • Overall health status
  • Organ function
  • Stage of cancer
  • Abnormal levels of chemicals and proteins in your blood that may indicate cancer
  • High or low blood cell count (possibly due to cancer)
  • Treatment options depending on the type and severity of cancer
  • If cancer has come back
  • Whether treatment is working or the disease is further developing

Although blood tests are useful in cancer diagnosis, other tests are necessary to confirm a diagnosis. Other tests to diagnose cancer include biopsies, x-rays, CT scans, MRIs, physical exams, mammograms, and pap smears. 

Complete Blood Count (CBC)

Doctors commonly order complete Blood Count (CBC) tests, often referred to as routine blood work. CBC looks for signs of anemia, nutritional deficiencies, infections, bone marrow problems, and helps diagnose blood cancers such as leukemia and lymphoma.

How CBC Tests Work

A CBC test measures blood cell components and provides information on their count, size, shape, and content. CBC tests measure: 

  1. White blood cells: fight infection
  2. Red blood cells: deliver oxygen throughout the body
  3. Platelets: help blood clot
  4. Hemoglobin: proteins that carry oxygen in red blood cells
  5. Hematocrit: the proportion of red blood cells to plasma (fluid component) in blood

Abnormal increases or decreases in cell counts can indicate if you have a medical condition that needs further evaluation. 

Who Should Receive CBC Tests

A complete blood count test is usually ordered as part of a routine yearly physical exam for all adults 30 years and older. Additional reasons for a CBC are:

  • If you are ill with a fever
  • Suspect an infection
  • Are consistently tired
  • Are losing weight without trying
  • If you have signs of cancer like general weakness, bruising, or bleeding

If you have a medical condition that requires you to take medication, you may have CBCs regularly to ensure your blood counts remain consistent.  

Blood Protein Testing

Blood protein tests help diagnose bone marrow cancers like multiple myeloma, Kahler’s disease (a cancer of plasma cells in the bone marrow), and Waldenstrom’s disease (a rare cancer that begins in white blood cells). 

Blood protein tests also diagnose nutritional problems, kidney or liver disease, and inflammation or infections like hepatitis B, C, and HIV. 

Health Image

Get Mira - Health Benefits You Can Afford.

Get doctor visits, lab tests, prescription, and more. Affordable copays. Available in 45+ states. Only $45/month on average.

How Blood Protein Testing Works

Blood protein testing uses a process called electrophoresis to measure two types of proteins in the blood: globulin and albumin. Albumin is the most abundant protein in the blood. Low levels of albumin can signal myeloma as the cancer may block its production. High levels of globulin can signal myeloma as it can cause an increase in production of globulin.

Who Should Receive Blood Protein Testing

Blood protein tests may be ordered as part of your routine health checkup if you have unexplained weight loss, fatigue, edema (swelling caused by extra fluid in your tissues), and kidney or liver disease symptoms.  

Tumor Marker Tests

Tumor marker tests can diagnose specific types of cancer and help inform treatment options but are not perfect. The results will likely require additional testing since they are not straightforward. 

For example, people without cancer might have high tumor marker levels, and those with cancer may not always have increased tumor marker levels. Some known tumor markers include ones for: liver, thyroid, ovarian, breast, colorectal, lung, stomach, pancreatic, and testicular cancer.     

How Tumor Marker Tests Work

Tumor marker tests detect the presence of tumor markers for various cancers. Tumor markers are substances made by your body’s normal response to cancer or cancerous cells. Tumor markers can indicate a specific type of cancer or several different types. Scientists are still learning about known tumor markers and researching new ones. 

Who Should Receive Tumor Marker Tests

Tumor marker tests are used to screen people at high risk of cancer due to family history and/or previous diagnosis of another type of cancer. They are most often used to guide treatment decisions, check treatment progress, predict the chance of recovery, and watch for recurrence.    

Circulating Tumor Blood Tests (CTC)

CTC tests help monitor breast, prostate, and colorectal cancers. A CTC test helps assess the course of the disease and can be used to measure treatment efficacy.  

How Circulating Tumor Blood Tests Work

The technology behind CTC tests is still in development and is designed to look for circulating tumor cells. Circular tumor cells are cells that have broken off of a tumor and are in the bloodstream, which may indicate the cancer is spreading.

Who Should Receive Circulating Tumor Blood Tests

Doctors may order a CTC test for patients who have been diagnosed with breast, prostate, or colorectal cancer. CTC tests are conducted before starting treatment and during the treatment period. 

Health Image

Virtual care for only $25 per visit

Virtual primary care, urgent care, and behavioral health visits are only $25 with a Mira membership.

Additional Diagnostic Methods for Cancer 

Routine bloodwork can help detect cancer, but doctors will use additional methods to confirm a cancer diagnosis. Other diagnostic tools for cancer include:

  • Imaging
  • Biopsy
  • Genetic testing
  • Additional specific blood tests

Not all cancers can be detected with blood tests either. For example, to diagnose skin cancer, patients will always require a skin biopsy. Breast cancer is diagnosed with imaging, specifically mammograms, and pap smears are used to screen for cervical cancer. 

Routine Blood Work Frequently Asked Questions (FAQs)

Routine blood work can give insight into your overall health and help you make informed health decisions. If it has been a while since your last blood test, you may have some of the questions below.  

What are other common blood tests? 

Other commonly recommended blood tests are A1C tests used to diagnose diabetes, lipid panels for assessing risk of heart disease, and STD panels for reproductive diseases. 

Where can I go to get blood work done? 

You can get blood work done in a health center, doctor’s office, clinic, lab, or hospital. Blood tests are performed by many healthcare providers, usually lab technicians and nurses. Getting your blood drawn can be stressful, but fortunately, it only takes about five minutes, 

How often do I need to get blood work done?

Personal factors such as age, sex, medications, family history, and current health status influence the frequency and type of blood work recommend. In general, adults should get routine blood work once a year. If blood test results come back abnormal, a follow-up with a  doctor is necessary. 

What treatment options are available for cancer?

Many different cancer treatments exist, with some people receiving one treatment and others receiving a combination of treatments. Cancer treatment utilizes surgery, radiation, medications, and other therapies to cure, shrink, or stop cancer progression. 

Bottom Line

Routine blood work can detect some cancers, especially blood cancers like leukemia, lymphoma, and multiple myeloma. A complete blood count test can detect cancer as well as many other health conditions to give insight into your overall health. Blood tests are also commonly used to monitor and assess cancer once a patient has already been diagnosed. Not everyone is recommended the same frequency and type of blood work.   

Blood work can be costly without insurance, yet it is crucial to detect illnesses before symptoms arise. Luckily, Mira offers comprehensive blood work for only $170, which covers essential lab screening for non-members, including a complete blood count test. Members receive up to 80 percent off of over 1,000 prescription medications and same-day lab testing for only $45 per month. Sign up today to get started.

Erica Kahn

Erica graduated from Emory University in Atlanta with a BS in environmental science and a minor in English and is on track to graduate with her Master's in Public Health. She is passionate about health equity, women's health, and how the environment impacts public health.