Cancer screening examines a patient for cancerous tissue before the patient develops any symptoms. These tests help find abnormal tissue growth. When abnormal tissue or cancer is found early, it may be easier for medical professionals to treat or cure.
Remember that just because your doctor referred you for a screening test, it does not always mean that they think you have cancer. Cancer screenings are performed when a person does not have any symptoms.
What is Cancer Screening?
Cancer screening tests are medical procedures that help health care providers take a closer look at a patient’s tissues and body functions. These tests detect and monitor abnormal tissue growth in a person’s body, which may indicate an increase in cancerous cells.
Cancer is a condition in which abnormal cells divide without control, potentially invading nearby tissues. Cancer cells may spread to other body parts through the circulatory and lymphatic systems.
Types of Cancer Screening
Depending on the patient’s medical history and the type of cancer being screened for, a doctor may recommend one of the following cancer screening tests:
A health care provider may take a detailed look at your body, looking for signs of disease or abnormalities such as lumps or other unusual tissue growth. They also review your medical history to see if any past illnesses may have resurfaced.
Different procedures test samples of tissue, blood, urine, and other bodily substances for signs of cancer.
This type of cancer screening utilizes machines that take pictures of areas inside the body, including
- Positron Emission Tomography (PET): This scan uses radiolabeled tracers to create images that measure body functions, which helps doctors see how well organs are functioning.
- Computed Tomography (CT): A CT scan uses X-rays (ionizing radiation) to create images that may be compiled into 3D images. A CT scan is ideal for examining tissue growth that contains calcifications, such as bone tumors.
- Magnetic Resonance Imaging (MRI): an MRI scan takes clear, cross-sectional images of soft tissues like most organs and the spinal cord.
- Low-dose CT (LDCT): An LDCT scan uses smaller amounts of radiation to examine the lungs of patients at high risk for lung cancer.
- Mammography: This type of scan takes X-rays of the breasts and is used to screen women at risk for breast cancer.
- Genetic tests: Genetic tests examine a patient’s cells or tissue to check for changes in genes or chromosomes. Genetic changes may signal a patient’s risk of having a specific disease or cancer.
Additional cancer screening procedures include
Alpha-fetoprotein blood test: Used to detect liver cancer early.
Breast MRIs: Useful for women who carry a harmful mutation in the BRCA1 gene or the BRCA2 gene.
CA-125 blood test:
Used to detect ovarian cancer early.
Multicancer early detection (MCED) tests: Used to measure biological signals in body fluids that may signal the presence of cancer cells (known as biomarkers or tumor markers).
Prostate-specific antigen (PSA) blood test: Used for prostate cancer screening.
Skin exams: Usually recommended for people at risk for skin cancer.
Transvaginal ultrasound imaging test: Creates pictures of a woman’s ovaries and uterus and inspects for ovarian cancer or endometrial cancer.
Virtual colonoscopy: Examines the colon and rectum without entering the body through invasive techniques.
Breast, Lung, and Other Cancers You Can Screen For
According to the CDC, getting regular screening tests may help find breast, cervical, and colorectal cancers early, when treatment is likely to work best.
Mammograms are a type of breast cancer screening that help find breast cancer early when it’s easier to treat and before symptoms appear. Breast MRIs are also often recommended for high-risk women.
Pap tests and human papillomavirus (HPV) tests are cervical cancer screening procedures that help find abnormal cells in the cervix. If undiscovered, these abnormal cells may turn into cancer.
Colorectal cancer describes both rectal and colon cancer. Cancerous cells in the colon are colon cancer, while cancerous cells in the rectum are rectal cancer. Precancerous polyps (abnormal growths) in the colon or rectum can be seen in colorectal cancer screening procedures. These procedures include stool tests, flexible sigmoidoscopy, colonoscopy, and CT colonography.
Low-dose computed tomography (LDCT) scans that screen for lung cancer are recommended for patients who have a history of smoking and are over 50 years old.
Measuring Cancer Risk
Cancer risk is measured in several different ways. According to the National Cancer Institute, three common ways medical scientists measure cancer risk are
Researchers estimate absolute risk by examining a large number of people from a certain population and counting the number of people in the group who suffer from a certain disease over a certain period. This measures a patient’s risk of developing a particular disease over time.
This type of research attempts to determine whether the risk of having a disease is linked to certain traits or factors. Researchers compare two identical groups that differ only in one trait or factor. The percentage of people exposed to said factor who have the disease is divided by the unexposed group who have the disease. This is also known as the risk ratio.
An odds ratio is an estimate of relative risk where a researcher doesn’t have enough information to determine relative risks. A case-control study utilizes an odds ratio, where the odds describe the number of times a particular trait or factor was present in a group of individuals who suffer from a specific disease, divided by the times it was absent.
Who Might Need a Cancer Screening?
Cancer screening tests are usually recommended only for patients with a high risk for cancer. Anything that increases the chance of cancer development is called a cancer risk factor.
Having risk factors for cancer does not guarantee that you will have cancer. Not having them does not guarantee that you won’t.
People who may fall into the high cancer risk category include those with
- A personal or family history of cancer
- Gene mutations linked to cancer
- Exposure to tobacco smoke and toxic chemicals
- An inexplicable blood clot developing within the body
- Older age
Cancer screening research investigates who has an increased risk of cancer.
Studying patients who have been through cancer screening tests can help scientists, such as those from the Surveillance, Epidemiology, and End Results (SEER) Program learn what causes different types of cancer, who should be screened, which screening tests are most helpful, and how often such tests should be used.
The United States Preventive Services Task Force (USPSTF) publishes screening recommendations that help physicians prescribe cancer screenings to patients based on the most recent research findings and scientific consensus.
Do Cancer Screenings Help You Live Longer?
For many cancers, the survival rate depends on the cancer stage when diagnosed.
In some cases, finding cancer in the early stage helps decrease the chance of cancer death because of increased opportunities for cancer treatment.
The World Health Organization notes that cancer survival rates for multiple types of cancer are significantly higher with early detection. The chances of survival depend on
- The specific kind of cancer
- Staging (how advanced the cancer is, and how much, if any, has spread)
- The timing of cancer detection
For some cancers, diagnosis and treatment do not improve the chances of a complete cure.
You must fully understand the benefits and harms of cancer screening tests to make an informed decision. You and your doctor should discuss whether or not screening is a good idea for you and decide on the best approach to cancer screening options.
Goals of Cancer Screening
The objectives of cancer screening include:
- Finding cancer before symptoms appear.
- Screening to treat and cure certain cancers more effectively.
- Decreasing the patient’s risks of dying from cancer.
A common misconception about cancer tests is that they are all meant to diagnose cancer. Screening tests usually do not diagnose cancer; They simply indicate that abnormal tissue growth is present within the patient’s body.
Additional tests may be necessary if abnormalities are found.
An example of a cancer diagnostic test is a biopsy, in which cells or tissue from a patient’s body are removed so a pathologist can examine them for signs of cancer.
Risks of Cancer Screening
Risks associated with cancer screening include
False-Negative Test Results
A false negative result would indicate that a patient does not have cancer, even when they do. This may result in the patient delaying medical care until critical symptoms appear.
False-Positive Test Results
False-positive test results show abnormalities when there is none. Such results may cause unnecessary anxiety for the patient and lead to subsequent (unnecessary) tests and procedures, which come with their own risks.
Overdiagnosis refers to finding cancer that will never cause any symptoms or damage. These abnormal tissue growths may stop growing or go away on their own. The drawbacks of overdiagnosis include anxiety and unnecessary treatment.
This refers to unnecessary treatment for a nonthreatening or asymptomatic condition. Usually stemming from overdiagnosis, overtreatment may lead to other, more critical health problems and harmful side effects.
Cancer Screening: Is It the Right Step For You?
Cancer prevention is vital for maintaining long-term health.
According to a recent publication from the American Cancer Society, early detection through screening reduces the risk of death, especially for people with an increased risk of developing colon, rectal, cervical, breast, prostate, or lung cancer.
Cancer screening may help inform treatment plans, resulting in a better prognosis.
Book an ezra full-body MRI for yourself today, or gift a screening to a loved one.