Cancer screening tests include tests that look for cancer in healthy people. By doing this, cancer can be detected in the early stages. This can make it easier to treat. There are several types of screening tests that look for signs of common cancers. In the following, you will learn about the different types of cancer screening tests, their benefits and risks, and how to perform different tests. Cancer screening can save lives; So do not miss this article.
What is a cancer screening test?
A cancer screening test looks for signs of cancer before symptoms appear. If abnormal or cancerous tissue is found in the early stages of its development, it will be easier to treat. The appearance of symptoms means that the cancer has grown and spread throughout the body, making it more difficult to treat the cancer. It is important to know that if your doctor suggests that you have a cancer screening test, he or she does not necessarily think you have cancer. These tests are done when you have no symptoms of cancer.
Different screening methods
Types of screening tests include:
- Photography: By photographing the internal areas of the body, the symptoms of cancer are examined.
- laboratory test: Includes sampling of tissue, blood, urine, or other substances extracted from the body.
- Genetic testing: In a genetic test performed in a laboratory, a cell or part of a tissue is examined for abnormal genes or chromosomes. Changes in the gene can indicate that a person is at risk for a specific disease or condition.
- Physical examination and history check: In this test, the body is examined for signs of health and illness, and doctors look for signs such as bumps or other abnormalities. The patient’s history also includes previous health habits, illnesses, and treatments.
What are the types of cancer screening tests?
There are several types of screening tests. Some of them are for finding cancers that, if detected early, can increase the patient’s chances of complete recovery. Other tests do not reduce the risk of cancer but may be prescribed; Especially for people who are at risk.
a. Tests that reduce cancer deaths
1. Colonoscopy, sigmoidoscopy and fecal blood test (FOBTs)
These tests have been able to reduce deaths from colon cancer. Colonoscopy and sigmoidoscopy can also prevent colon cancer, as they can detect abnormal bowel glands (polyps) and remove them before they become cancerous. Experts recommend that people at risk for colon cancer be screened for cancer between the ages of 50 and 75.
۲. Low-dose layered radiography
This test is performed for lung cancer and has been able to reduce the lung cancer caused by the harms of smoking in people between the ages of 55 and 74.
Mammography is used to diagnose breast cancer and has been able to significantly reduce mortality from the disease in people aged 40 to 74 years.
4. Pap smear and HPV
These tests reduce the incidence of cervical cancer screening because they allow abnormal cells to be identified and treated before they become cancerous. They can also reduce deaths from cervical cancers. It is recommended that Pap smear and HPV be started at age 21 and continue until age 65, if the results of the latest tests are normal.
B. Other cancer screening tests
5. Alpha-photoprotein blood test
This test is sometimes used in conjunction with liver ultrasound and is used to diagnose liver cancer early in people at risk.
6. Chest umbilical cord
This imaging is commonly used for women who have a dangerous mutation in the BRCA1 or BRCA2 gene. These people are at high risk for breast cancer and may be at risk for other cancers.
7. CA-125 test
This blood test, usually done with a vaginal ultrasound, is used to diagnose ovarian cancer. This early diagnosis is usually made in women who are at high risk. This test is also used to diagnose ovarian cancer in women who have symptoms and can be used to check for recurrence of the cancer. You should know that this test has little use in ovarian cancer screening and is mostly used for diagnosis.
8. Medical and normal examination of the breast
According to research, regular breast examinations by women themselves or medical staff have not reduced breast cancer mortality. However, if a bulge or abnormal change is felt, it is important to be examined.
9. PSA test
This blood test, which is usually accompanied by a digital rectal exam, is a way to diagnose early-stage prostate cancer; However, experts do not recommend regular prostate cancer screening for most men because studies have shown that it has very little effect on death from prostate cancer and may lead to additional diagnosis and treatment.
10. Skin examination
Doctors often recommend that people who are at risk for skin cancer have their skin examined regularly by medical agents. According to studies, this test had no effect on the risk of death from skin cancer; However, people should be aware of their skin changes and see a doctor immediately if a new mole appears or an old mole changes shape.
۱۱. Vaginal ultrasound
This test can show images of a woman’s uterus and ovaries. It is sometimes used in people who are at high risk for ovarian cancer or endometrial wall cancer (due to Lynch syndrome). According to research, this method also has no role in preventing death from cancer.
What is the purpose of a screening test?
Screening test is useful and principled if:
- Reduce the risk of cancer death;
- Diagnose cancer before symptoms appear;
- Rarely have a positive answer and a negative answer;
- Screen for cancers that are easier to treat and cure if diagnosed quickly.
Screening tests are not for cancer. If an abnormal test result is obtained, more tests should be done to diagnose cancer; For example, if a mammogram shows a lump in the breast, it could be cancerous or noncancerous. To diagnose it, it is necessary to perform tests such as sampling and examine the tissue under a microscope.
Who needs a cancer screening test?
Some tests are only recommended for people who are at high risk for certain cancers. The factor that increases the risk of cancer is called the risk factor for cancer. Having a high-risk cancer factor does not mean that you will definitely get cancer, and not having a high-risk cancer factor does not mean that you will not get cancer.
Some screening tests are done for people who have a high risk of certain cancers, especially people who:
- They are old;
- Have a personal history of cancer;
- Have a family history of cancer;
- Blood clots form in their body for no apparent reason;
- There are mutations in some genes that are linked to cancer;
- They are exposed to carcinogens such as tobacco or chemicals in their workplace.
These people, who have a high risk of cancer, should have more screening tests than their peers.
Can cancer screening prolong life?
In some cases, finding cancer early and before symptoms can reduce the risk of death. For many cancers, the chance of recovery depends on the stage at which the cancer is diagnosed. Cancer that is detected in the early stages of growth and development is usually easier to treat.
Research has looked at the mortality rates of people who were screened and those who were not screened for certain cancers. Some cancer screening tests have been shown to detect cancer early and reduce the risk of dying from it. These experiments were described to you in the previous sections of the text.
Cancer screening test in Iran
Because unhealthy lifestyles and environmental factors have led to an increase in cancer rates, cancer screening programs have been considered in Iran. For screening, which has recently been developed in the field of cervical, breast and colon cancer, you need to go to a health care facility and be referred for screening depending on your condition and risk factor.
Is a cancer screening test dangerous?
Not all screening tests are useful. Some of them have risks. It is important to know the risks of each test and its effect on reducing mortality so that you can make the right decision to do so. You may experience the following risks when performing a screening test:
- The test result may be positively incorrect;
- The test result may be negative;
- Finding cancer may not improve the patient’s health or longevity;
- A variety of tests may cause bleeding or other problems, for example, colonoscopy or sigmoidoscopy for bowel cancer screening may cause a rupture in the intestinal wall;
- Cancer screening test results may seem normal, but cancer is present. Getting medical attention may be delayed even if you have symptoms of cancer if you get a negative answer.
- The results of a cancer screening test may look abnormal, but there is no cancer. A false positive can lead to anxiety and can lead to other tests that can be dangerous.
Some cancers never cause fatal symptoms; But if found in a screening test, the cancer may be curable. Receiving treatment for this cancer cannot be said to help a person live longer or not receive it. Adolescents and adults are less likely to attempt suicide in the first year after being diagnosed with cancer. Also, cancer treatment may have side effects.
It is important to be aware of the risk of various cancers at these ages and consult your doctor about this. You can save your life and live a long and healthy life if you are examined for the presence of high-risk factors and screened correctly.