Many symptoms, in addition to screening exams, suggest an individual may have cancer. So, ‘How Is Cancer Diagnosed?’. This is the first of a two-part article discussing just that. This first article will cover how lab work and imaging are used, and the second article will cover the various biopsies used to diagnose or rule out cancer.
Your physician will work to find out if there is a cancer diagnosis or another cause for your symptoms. The doctor will need your personal and family medical history, and will likely give you a physical exam.
You may be sent to the lab for blood work, or a urine screen. These workups can show if there are any substances or abnormal results which could indicate cancer is possible. There are tests for tumor markers that are sometimes ordered. Tumor markers are produced by cancer or other cells in your body in response to cancer. These can be present in some conditions that are not cancer.
Imaging takes pictures of the inside of your body so a doctor can see if a tumor is present. Here we review different tests which use imaging.
This machine is similar to x-rays, designed to take a series of pictures from different angles of your organs. These pictures then create detailed 3-D images of the inside of the body. A CT machine is a donut-shaped scanner that moves around you, as you lie still on a table.
You may or may not receive a dye or contrast material before the scan. This can be given by a needle placed into your vein, or you may be asked to drink the dye. This helps to highlight areas of your body, making images easier to see.
MRI machines use radio waves and a powerful magnet to take pictures, in slices, of your body. The slices provide details of the inside of your body that can show the difference between healthy and unhealthy tissue.
The MRI machine makes loud noises so you should be given ear plugs to put in prior to lying on the table that puts you into a long, round chamber. Dye or contrast may be given by a needle into your vein during or prior to the exam. This dye can make tumors show up brighter in the pictures.
A nuclear, or radionuclide scan, uses radioactive material to take pictures of the inside of your body.
Before this type of scan, you will receive a small amount of radioactive material, called a tracer, in your vein. The tracer flows through your bloodstream, collecting in certain bones or organs. While lying still on the table, a scanner detects and measures radioactivity inside your body and creates pictures of bones or organs. The radioactive material will lose its radioactivity over time, and leaves the body through your urine or stool.
An ultrasound uses high-energy sound waves which echo off tissues in your body using a computer to create pictures. This exam is performed by a technician while you lay on a table. The technician uses a device called a transducer, covered in warm gel, to glide over the body part being examined. The picture created is called a sonogram.
X-rays create pictures of the inside of your body using low-dose radiation. After being placed in position, the x-ray beam is directed to the correct body part. You need to stay very still, possibly holding your breath.
(National Cancer Institute, n.d.)
(American Cancer Society, n.d.)