How to detect cancer is a not one short answer. Neither it is a standard answer as there are a large array of tests available to facilitate the process. The medical, social and economic benefit of diagnostic tests are often overlooked, despite that these tests improve patient care and help to limit healthcare spending.
Significant number of medical decisions are based on these test results. Diagnostics have a decisive impact on the continuum of care and on early diagnosis when it comes to cancer.
How to detect cancer?
- Lab tests: Unexplained fluctuations of certain substances in your body can be a sign of cancer. These changes can be determined by lab tests of blood, urine or other body fluids. Some lab tests involve testing blood or tissue samples for tumor markers. Tumor markers are substances that are produced by cancer cells or by other cells of the body in response to cancer. Most tumor markers are made by normal cells and cancer cells, but they are produced at much higher levels by cancer cells. However, abnormal lab results alone are not sure sign of cancer.
- Diagnostic imaging: An imaging test is a way to let doctors see what’s going on inside your body, whether a tumor is present or not. These tests send forms of energy (like x-rays, sound waves, radioactive particles or magnetic fields) through your body. Body tissues change the energy patterns to make an image or picture. These pictures show how your insides look and work so that health care providers can see changes that may be caused by disease like cancer. These pictures can be made in several ways:
- In CT scan a series pictures of your organs from various angles are taken to create detailed 3D images. During the CT scan, you will lie still on a table that slides into a donut-shaped scanner. The scanner moves around you, taking pictures.
- A powerful magnet and radio waves are used in an MRI to take pictures of your body in slices. These sliced images of the inside of your body show the difference between healthy and unhealthy tissue. During an MRI, you lie still on a table that is pushed into a long, round chamber. The MRI makes loud thumping noises and rhythmic beats.
- A nuclear scan uses radioactive material to take pictures of the inside of the body. You receive an injection of a small amount of radioactive material before scan. It flows through your bloodstream and collects in certain bones or organs. During the scan, you lie still on a table while a machine called scanner detects and measures the radioactivity in your body, creating pictures of bones or organs on a computer screen or on a film. The radioactive material in your body will lose its radioactivity over time. It may be excreted from the body. A PET scan is a type of nuclear scan that makes detailed 3D pictures of areas inside your body where glucose is taken up. Because cancer cells often take up more glucose than healthy cells, the pictures can be used to find cancer in the body.
- An ultrasound exam uses high-energy sound waves that people cannot hear. The sound waves echo off tissues inside your body. A computer uses these echoes to create pictures of areas inside your body. During an ultrasound exam, you will lie on a table while a technician slowly moves a device called a transducer on the skin over the part of the body that is being examined. A gel is used to make it easily glide over the skin.
- X-rays use low doses of radiation to create pictures inside of your body. While the images are taken, you will be positioned in such a way that directs an x-ray beam on the correct part of the body. You need to stay still and may need to hold your breath for a second or two.
- Biopsy: In majority of the cases, doctors need to do a biopsy in order to diagnose cancer. In this procedure the doctor removes a sample of tissue, which is assessed by a pathologist using various tests and observed under microscope to see if the tissue is cancer. These findings are reported in a histo-pathology report, which contains details about your diagnosis. These reports play an important role in diagnosing cancer and helping decide treatment options. Biopsy samples may be withdrawn as a tissue or fluid with a needle in case of bone marrow aspirations, spinal taps and some solid tumors such as breast. At times doctor uses a thin, lighted tube called an endoscope to examine areas inside the body. Endoscopes go into natural body openings, such as the mouth or anus. Any abnormal tissue along with some of the surrounding normal tissue is removed through the endoscope by the doctor during the exam. Colonoscopy is an example of endoscopy. During operation a surgeon may remove an area of abnormal cells. Some biopsies may require a sedative or anesthesia.
Efficacious diagnostic tests are used to confirm or eliminate the presence of cancer, monitor the disease process, and to plan for and evaluate the effectiveness of treatment. The complete evaluation of a patient usually requires a thorough history and physical examination along with diagnostic testing; this is the method of how to detect cancer. Many tests are needed to determine whether a person has cancer, or if another condition (such as an infection) is mimicking the symptoms of cancer. There is no single test that can accurately diagnose cancer.