Cancer is an uncontrolled growth of cells in the body. Diagnostic tests used to detect cancer vary depending on the type of cancer. So a test your doctor orders to diagnose pancreatic cancer may not be the same one they may use to diagnose blood cancer. If your doctor attempts to detect cancer before symptoms appear, they may use a cancer screening test.
Below are a few common tests used to diagnose cancer and assess overall health.
What types of tests are used to detect cancer?
Blood tests
Blood tests can test for different substances in the blood that may indicate the presence of cancer (tumor markers). Examples of blood tests include:
- Complete blood count: A complete blood count (CBC) measures the number of red blood cells, white blood cells and platelets in the blood.
- Urea and electrolytes: These tests show how well the kidneys are working. They also check for electrolytes (such as sodium, potassium, chloride and bicarbonate).
- Liver function tests (LFTs): These tests check how well the liver is working. LFTs look for levels of enzymes and proteins made by the liver or that are cleared by the liver.
- Tumor markers: Tumor markers are substances that may show in increased levels if cancer is present. They are usually proteins, and can be found in the blood, urine or body tissues. Some tumor markers are only produced by one type of cancer, while others can be produced by several types of cancers. Markers can sometimes be found in noncancerous conditions as well. If a patient has cancer, tumor markers can be used to diagnose the disease, monitor how well cancer treatment is working or check if the cancer has come back (relapse).
X-rays
X-rays help doctors look for cancer in various areas in the body, including the kidneys, stomach and bones. X-rays are generally quick, painless and do not require any special preparation.
In special types of X-ray tests, contrast dyes may be used. Contrast materials (such as barium, an iodine-based dye) combined with X-rays may obtain better images for cancer detection.
Computed tomography (CT) scan
During a CT scan, X-rays are used to take images of the inside of the body from various angles. Then, a computer combines the pictures into a three-dimensional, detailed image that can help to reveal any tumors or abnormalities. In some cases, doctors may use a specialized dye called contrast medium, which is administered to the patient before taking the images. This dye helps provide better image detail.
A total-body CT scan typically includes at least the abdomen, chest and pelvis and is usually done for cancer staging. Common scanned areas include:
- Neck
- Head
- Abdomen
- Chest
- Limbs
- Pelvis
- Magnetic resonance imaging (MRI)
An MRI scan uses powerful radio waves and magnets to generate computer-generated, detailed images of the body. Doctors also use MRI scans to measure tumor size.
An MRI doesn’t use X-rays or other types of radiation. Because of this, physicians often use MRI scans when looking for issues in male and female reproductive systems. MRIs are typically safe, even for pregnant patients. Doctors also use MRIs to take pictures of the spinal column, brain, chest, abdomen and breast.
Ultrasound, ultrasonography or sonography
An ultrasound creates images of internal organs using high-frequency sound waves. These sound waves hit the organs, bouncing back to a device called a transducer. The transducer takes the sound waves and turns them into pictures shown on a computer.
The sound waves echo uniquely when bouncing off healthy and abnormal tissue, helping doctors detect possible tumors. There is no X-ray exposure in ultrasound tests, which means they are safe for pregnant women.
Positron emission tomography and computed tomography (PET-CT) scans
Doctors can combine PET scans with CT scans as an effective imaging test for finding cancer and detecting its stage. This type of scan may help your doctor to start the best treatment as early as possible. With a PET scan, they may even be able to predict the chances of recovery.
Mammography
Mammography is a type of X-ray that doctors use to check for breast cancer. Mammograms produce images that may show tumors that can’t be felt during physical examination. Mammograms can also reveal other breast irregularities.
Nuclear medicine scans for cancer
Nuclear medicine scans generate images based on the body’s chemistry, unlike other imaging tests that are based on physical forms and shapes. The scans use liquid substances known as radionuclides, radiopharmaceuticals or tracers that release low radiation levels.
Body tissues affected by some diseases, such as cancer, may absorb more or less of the tracer than normal tissues. Specific cameras capture the radioactivity pattern and generate images that show the doctor where the tracer travels as well as where it is getting collected.
If cancer is present, the tumor may show up on the image as a hot spot. The tumor may also show up as a cold spot depending on what type of scan your doctor performs. A cold spot is the area of less cell activity or decreased uptake. Your doctor will determine the type of nuclear scan you will receive, depending on the organ they wish to investigate. Common nuclear scans used for cancer include:
- Bone scans
- Gallium scans
- Multigated acquisition scans
- Thyroid scans
Nuclear scans may not identify tiny tumors and can’t always indicate whether a tumor is cancer.
Annual checkups are an important protection for overall health, including safeguarding against cancer.
Top What Tests Are Done to Check Cancer? Related Articles
Breast Cancer Quiz
This Breast Cancer Quiz features signs, symptoms, facts, causes, common forms, terms, risk factors, statistics, and more. Increase your awareness of breast cancer now!
Can a CT Scan Tell if a Lung Nodule Is Cancerous?
No, a computed tomography (CT) scan cannot tell with certainty whether a lung nodule is cancerous. It can only indicate an abnormal spot in the lung that is opaque. This opaque spot may or may not be cancer.
Can Cancer Be Detected by a Blood Test?
While blood tests can’t absolutely detect all cancers, certain blood tests can give your doctor an idea of how your organs are functioning and if they have been affected by cancer.No blood test can detect colon cancer. However, your doctor may order blood tests to get a picture of your overall health and use other screening methods to look for signs of colon cancer.
How Is Liver Cancer Usually Diagnosed?
The liver is the second largest organ (the first being the skin) in the human body. One blood test used to help diagnose liver cancer is the tumor marker alpha-fetoprotein (AFP), but it is not specific to liver cancer.
Cancer
Cancer is a disease caused by an abnormal growth of cells, also called malignancy. It is a group of 100 different diseases, and is not contagious. Cancer can be treated through chemotherapy, a treatment of drugs that destroy cancer cells.
Cancer 101 Slideshow
Learn the basics about cancer including types, causes, how it spreads, symptoms and signs, stages and treatment options. Read about the common type of cancers.
Cancer Quiz
Take this quiz to learn the causes of cancer. Get the facts about the causes, symptoms, and treatments for the world's most common cancers.
Colon and Colorectal Cancer Screening
Colon cancer is preventable by removing precancerous colon polyps, and it is curable if early cancer is surgically removed before cancer spreads to other parts of the body. Therefore, if screening and surveillance programs were practiced universally, there would be a major reduction in the incidence and mortality of colorectal cancer.
How Can Cancer Be Diagnosed?
Along with your medical history and a physical exam, multiple diagnostic tests can be used to help your doctor confirm or eliminate the presence of cancer.
How Can You Detect Liver Cancer Early?
It is often hard to detect liver cancer at early stages because they do not present any symptoms until they are advanced. Small liver tumors are difficult to identify during a physical examination because most of the liver is covered by the rib cage.
How Long Do You Live After Being Diagnosed With Bone Cancer?
When diagnosed and treated during the early stages, most people with bone cancer can have long and productive lives. Learn the five-year survival rate, types, and warning signs of bone cancer.
How Do You Test Yourself for Lung Cancer?
Lung cancer is the second leading cause of death in the United States. It is hard to detect in the early stages because it does not cause obvious signs and symptoms. Signs and symptoms most often appear when lung cancer has grown deep and extensively inside the lung tissue and/or spread to other organs.
Know Your Lung Cancer Facts Quiz
Lung cancer is the number one cause of cancer deaths in both men and women in the U.S. and worldwide. Get the facts about lung cancer with this quiz.
Cancer: Symptoms of Common Cancers in Men
Can men get breast cancer? Cancer symptoms men need to watch out for include skin changes, difficulty swallowing, rapid weight loss, a breast mass, and more. Learn possible clues to finding and detecting cancer early.Will a Chest X-Ray Show Lung Cancer?
When diagnosing lung cancer, chest X-rays do not provide a definitive diagnosis of lung cancers at an early stage (when they are more treatable). Until the lung cancer shows up on a chest X-ray, the tumor is often too far advanced to be cured. Often, many things seen on a chest X-ray turn out to be treatable problems or artifacts.