No, a single blood test does not show most cancers on its own, but they are crucial for general health checks and can detect markers for certain cancers like blood cancers (leukemia) or prostate cancer (PSA), though other tests like biopsies, scans, and imaging are needed for a definitive diagnosis of most solid tumors. While routine blood work (like a CBC) can hint at issues, specific tumor marker tests and newer multi-cancer early detection (MCED) blood tests are used alongside other diagnostics to find abnormalities, but a biopsy is the only way to confirm cancer.
A CBC can detect some blood or immune system cancers like leukemia and lymphoma. But it can't detect solid organ cancers like lung, breast or colon cancers. It can tell your provider how your body responds to treatment and whether the cancer has spread to your bone marrow.
Aside from leukemia, most cancers cannot be detected in routine blood work, such as a CBC test. However, specific blood tests are designed to identify tumor markers, which are chemicals and proteins that may be found in the blood in higher quantities than normal when cancer is present.
Blood tests are not used in isolation
Even blood tests used to detect certain tumor markers are no guarantee that cancer is present. Ovarian cancer, for instance, often causes a rise in CA-125 levels, a protein found on the surface of certain cells.
Screen for 50+ cancers with a single blood test
The Galleri® multi-cancer early detection test identifies DNA in the bloodstream shed by cancer cells1 and does not predict future genetic risk for cancer.
Early detection can dramatically improve cancer outcomes, but some cancers remain stubbornly difficult to diagnose at early stages. Pancreatic, ovarian, lung, liver, and kidney cancers present unique challenges that often delay diagnosis until the disease has advanced.
The blood tests have potential to screen for cancers, find them early and give patients a much greater chance of being cured. This has been made possible by a simple blood test that can not only detect more than 50 types of cancer, but also pinpoint where it's coming from with striking accuracy.
Twenty potential signs of cancer include **unexplained weight loss, persistent fatigue, unusual lumps or swelling, skin changes (sores that don't heal, new moles, color changes), changes in bowel/bladder habits, persistent cough or shortness of breath, hoarseness/voice changes, difficulty swallowing, persistent indigestion, unexplained pain, night sweats, unusual bleeding/bruising, mouth sores that won't heal, loss of appetite, fever, changes in vision/headaches, swelling in lymph nodes, nipple changes, painful urination/ejaculation, and swelling in the face/neck; these warrant a doctor's visit if they last more than a few weeks.
Circulating tumor cell tests detect cancer cells in your blood. The cells might be in the blood if they've broken away from where they started and are spreading to other parts of the body. Circulating tumor cell tests are mostly used after a cancer diagnosis.
What does cancer fatigue feel like? People with cancer often describe the fatigue as making them feel tired, weak or exhausted. The fatigue can be physical or emotional. It often isn't helped by usual measures, such as resting or getting a good night of sleep.
However, despite their invaluable role in cancer detection, general practitioners typically don't offer official cancer diagnoses. Instead, if cancer is suspected, your PCP will send you to a cancer specialist for more advanced care. This written order to receive care from an oncologist is called a referral.
Many cancers actually cause your red blood cells to drop. However, there are some cancers that can result in a high red blood cell count, including: Polycythemia vera (a rare blood cancer that causes your body to make too many red blood cells). Renal cell carcinoma (the most common type of kidney cancer among adults).
A full blood count (FBC) is a common blood test that measures different cells in your blood, including red blood cells, white blood cells and platelets. An FBC can help diagnose infections, blood disorders and clotting problems. If your results are higher or lower than usual, it doesn't always mean there is a problem.
According to 2022 data from the American Cancer Society, screening mammograms may miss up to 1 in 8 cancers, particularly in dense breasts.
Neurological disease such as stroke, motor neurone disease, Alzheimer's and multiple sclerosis aren't diagnosable from blood tests.
Just as an abnormal result doesn't necessarily mean you have cancer, test results that come back normal don't guarantee that you don't. Most cancers are not yet detectable through blood testing. Blood tests should be seen as one part of an overall screening for potential cancer.
During a physical exam, your doctor may look for abnormalities, such as changes in skin color or enlargement of an organ, that may indicate the presence of cancer. Laboratory tests. Laboratory tests, such as urine and blood tests, may help your doctor identify abnormalities that can be caused by cancer.
Galleri multi-cancer early detection (MCED) blood test. Research in England and Wales is looking at a new blood test to see if it can detect a range of cancers. This is called the Galleri multi-cancer early detection test. Or the Galleri blood test for short.
Some general signs and symptoms associated with, but not specific to, cancer, include: Fatigue. Lump or area of thickening that can be felt under the skin. Weight changes, including unintended loss or gain.
About 90% of cancers are caused by environmental and lifestyle factors, not genetics, including smoking, poor diet (red meat, fried foods), alcohol, sun exposure, pollutants, infections, obesity, and inactivity; only 5–10% are due to inherited genetic defects, with most cancers arising from lifestyle-induced genetic mutations. Tobacco alone accounts for about a third of cancer deaths, while diet, obesity, and inactivity contribute significantly, with controllable factors being key to prevention.
When cancer is suspected there is a fast route within the NHS to get further tests and specialist advice to rule out cancer. These are called 2 week wait referrals and you should be seen within 2 weeks of being referred.
Multi-cancer detection (MCD) tests, also known as multi-cancer early detection (MCED) tests, are a new type of lab test that looks for signs of many types of cancer from one sample. These tests are not yet FDA-approved, but some are now available.
Most types of lymphoma can't be diagnosed by a blood test alone. However, most people affected by lymphoma will have blood tests as part of their diagnosis and frequently throughout treatment. You continue to have blood tests, though less frequently, after treatment during follow-up.
Xgenera's test, miONCO, is an MCED test designed to detect early signs of 12 common cancers from just 150 micro-litres of blood. While the test is designed to detect these cancers, the ongoing trial will focus on a subset of five to six to validate its efficacy.