What is screening?

Screening is looking for cancer before a person has any symptoms. This can help find cancer at an early stage. When abnormal tissue or cancer is found early, it may be easier to treat. By the time symptoms appear, cancer may have begun to spread.

Scientists are trying to better understand which people are more likely to get certain types of cancer. They also study the things we do and the things around us to see if they cause cancer. This information helps doctors recommend who should be screened for cancer, which screening tests should be used, and how often the tests should be done.

It is important to remember that your doctor does not necessarily think you have cancer if he or she suggests a screening test. Screening tests are given when you have no cancer symptoms.
If a screening test result is abnormal, you may need to have more tests done to find out if you have cancer. These are called diagnostic tests.

There are different kinds of screening tests

Screening tests include the following:

  • Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken;
  • Laboratory tests: Medical procedures that test samples of tissue, blood, urine, or other substances in the body;
  • Imaging procedures: Procedures that make pictures of areas inside the body;
  • Genetic tests: Tests that look for certain gene mutations (changes) that are linked to some types of cancer.

Some screening tests can cause serious problems

Some screening procedures can cause bleeding or other problems. For example, colon cancer screening withsigmoidoscopy or colonoscopy can cause tears in the lining of the colon.

Finding the cancer may not improve the person’s health or help the person live longer

Some cancers never cause symptoms or become life-threatening, but if found by a screening test, the cancer may be treated. There is no way to know if treating the cancer would help the person live longer than if no treatment were given. In both teenagers and adults, there is an increased risk of suicide in the first year after being diagnosed with cancer. Also, treatments for cancer have side effects.

For some cancers, finding and treating the cancer early does not improve the chance of a cure or help the person live longer.

What is Cancer Screening?

Key Points

  • Cancer screening is looking for cancer before a person has any symptoms;
  • There are different kinds of screening tests;
  • Screening tests have risks:
    • Some screening tests can cause serious problems;
    • False-positive test results are possible;
    • False-negative test results are possible;
    • Finding the cancer may not improve the person’s health or help the person live longer.

Cancer screening is looking for cancer before a person has any symptoms

Screening tests can help find cancer at an early stage, before symptoms appear. Whenabnormal tissue or cancer is found early, it may be easier to treat or cure. By the time symptoms appear, the cancer may have grown and spread. This can make the cancer harder to treat or cure.

It is important to remember that when your doctor suggests a screening test, it does not always mean he or she thinks you have cancer. Screening tests are done when you have no cancer symptoms.

Screening tests have risks

Not all screening tests are helpful and most have risks. It is important to know the risks of the test and whether it has been proven to decrease the chance of dying from cancer.

False-positive test results are possible

Screening test results may appear to be abnormal even though there is no cancer. A false-positive test result (one that shows there is cancer when there really isn’t) can cause anxiety and is usually followed by more tests and procedures, which also have risks.

False-negative test results are possible

Screening test results may appear to be normal even though there is cancer. A person who receives a false-negative test result (one that shows there is no cancer when there really is) may delay seeking medical care even if there are symptoms.

General Information About Breast Cancer

What Is Informed and Shared Decision-Making?

Key Points

  • It is important that you understand the benefits and harms of screening tests and make an informed choice about which screening tests are right for you.

It is important that you understand the benefits and harms of screening tests and make an informed choice about which screening tests are right for you

Before having any screening test, it is important that you discuss the test with your doctor or other health care provider. Every screening test has both benefits and harms. Your health care provider should talk to you about the benefits and harms of a screening test and include you in the decision about whether the screening test is right for you. This is called informed and shared decision-making.

  1. Your health care provider will talk to you about the possible benefits, harms, and unknowns of a screening test. This may include information about the benefits of finding a cancer early or the harms related to false test results, overdiagnosis, andovertreatment. Your health care provider may also give you information in a leaflet, booklet, video, website, or other material.
  2. After you understand the benefits and harms of a screening test, you can decide whether or not you want to have the screening test based on what is best for you. Sometimes the harms and benefits are closely matched and the decision about whether to have a screening test is hard to make.
  3. Your health care provider will write your decision down in your medical record and order the screening test, if that was your decision.

Who Needs to Be Screened?

Key Points

  • Certain screening tests may be suggested only for people who have a high risk for certain cancers;
  • Cancer screening research includes finding out who has an increased risk of cancer.

Cancer screening research includes finding out who has an increased risk of cancer

Scientists are trying to better understand who is likely to get certain types of cancer. They study the things we do and the things around us to see if they cause cancer. This information helps doctors figure out who should be screened for cancer, which screening tests should be used, and how often the tests should be done.

Since 1973, the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institutehas been collecting information on people with cancer from different parts of the United States. Information from SEER, research studies, and other sources is used to study who is at risk.

Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast

The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. Lobules end in dozens of tiny bulbs that can produce milk. The lobes, lobules, and bulbs are linked by thin tubes called ducts.

Each breast also contains blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluidcalled lymph. Lymph vessels lead to organs called lymph nodes. Lymph nodes are small bean-shaped structures that are found throughout the body. They filter substances in lymph and help fight infection and disease. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.

See the following PDQ summaries for more information about breast cancer:

  • Breast Cancer Prevention;
  • Breast Cancer Treatment;
  • Genetics of Breast and Gynecologic Cancers.

Breast Cancer Screening

Key Points

  • Tests are used to screen for different types of cancer;
  • Three tests are used by health care providers to screen for breast cancer:
    • Mammogram;
    • Clinical breast exam (CBE);
    • MRI (magnetic resonance imaging) in women with a high risk of breast cancer.
  • Other screening tests are being studied in clinical trials:
    • Thermography;
    • Tissue sampling.

Three tests are used by health care providers to screen for breast cancer:

Mammogram

Mammography is the most common screening test for breast cancer. A mammogram is an x-ray of the breast. This test may find tumors that are too small to feel. A mammogram may also find ductal carcinoma in situ (DCIS). In DCIS, there are abnormal cells in the lining of a breast duct, which may become invasive cancer in some women.

Mammograms are less likely to find breast tumors in women younger than 50 years than in older women. This may be because younger women have denser breast tissue that appears white on a mammogram. Because tumors also appear white on a mammogram, they can be harder to find when there is dense breast tissue.

The following may affect whether a mammogram is able to detect (find) breast cancer:

  • The size of the tumor;
  • How dense the breast tissue is;
  • The skill of the radiologist.

Women aged 40 to 74 years who have screening mammograms have a lower chance of dying from breast cancer than women who do not have screening mammograms.

Clinical breast exam (CBE)

A clinical breast exam is an exam of the breast by a doctor or other health professional. The doctor will carefully feel the breasts and under the arms for lumps or anything else that seems unusual. It is not known if having clinical breast exams decreases the chance of dying from breast cancer.

Breast self-exams may be done by women or men to check their breasts for lumps or other changes. It is important to know how your breasts usually look and feel. If you feel any lumps or notice any other changes, talk to your doctor. Doing breast self-exams has not been shown to decrease the chance of dying from breast cancer.

MRI (magnetic resonance imaging) in women with a high risk of breast cancer

MRI is a procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). MRI does not use any x-rays.

MRI is used as a screening test for women who have one or more of the following:

  • Certain gene changes, such as in the BRCA1 or BRCA2 genes;
  • A family history (first degree relative, such as a mother, daughter or sister) with breast cancer;
  • Certain genetic syndromes, such as Li-Fraumeni or Cowden syndrome.

MRIs find breast cancer more often than mammograms do, but it is common for MRI results to appearabnormal even when there isn’t any cancer.

Other screening tests are being stud

Thermography

Thermography is a procedure in which a special camera that senses heat is used to record the temperature of the skin that covers the breasts. A computer makes a map of the breast showing the changes in temperature. Tumors can cause temperature changes that may show up on the thermogram.

There have been no clinical trials of thermography to find out how well it detects breast cancer or if having the procedure decreases the risk of dying from breast cancer.

Tissue sampling

Breast tissue sampling is taking cells from breast tissue to check under a microscope. Abnormal cells in breastfluid have been linked to an increased risk of breast cancer in some studies. Scientists are studying whether breast tissue sampling can be used to find breast cancer at an early stage or predict the risk of developing breast cancer. Three ways of taking tissue samples are being studied:

  • Fine-needle aspiration: A thin needle is inserted into the breast tissue around the areola (darkened area around the nipple) to take out a sample of cells and fluid;
  • Nipple aspiration: The use of gentle suction to collect fluid through the nipple. This is done with a devicesimilar to the breast pumps used by women who are breast-feeding;
  • Ductal lavage: A hair-size catheter (tube) is inserted into the nipple and a small amount of salt water is released into the duct. The water picks up breast cells and is removed.

Anxiety from additional testing may result from false positive results

False-positive results from screening mammograms are usually followed by more testing that can lead to anxiety. In one study, women who had a false-positive screening mammogram followed by more testing reported feeling anxiety 3 months later, even though cancer was not diagnosed. However, several studies show that women who feel anxiety after false-positive test results are more likely to schedule regular breast screening exams in the future.

Mammograms expose the breast to radiation

Being exposed to radiation is a risk factor for breast cancer. The risk of breast cancer from radiation exposure is higher in women who received radiation before age 30 and at high doses. For women older than 40 years, the benefits of an annual screening mammogram may be greater than the risks from radiation exposure.

There may be pain or discomfort during a mammogram

During a mammogram, the breast is placed between 2 plates that are pressed together. Pressing the breast helps to get a better x-ray of the breast. Some women have pain or discomfort during a mammogram.

What Is Informed and Shared Decision-Making?

Key Points

  • Screening tests have many goals;
  • Screening tests are not meant to diagnose cancer.

Screening tests have many goals

A screening test that works the way it should and is helpful does the following:

  • Finds cancer before symptoms appear;
  • Screens for a cancer that is easier to treat and cure when found early;
  • Has few false-negative test results and false-positive test results;
  • Decreases the chance of dying from cancer.

Screening tests are not meant to diagnose cancer

Screening tests usually do not diagnose cancer. If a screening test result is abnormal, more tests may be done to check for cancer. For example, a screening mammogrammay find a lump in the breast. A lump may be cancer or something else. More tests need to be done to find out if the lump is cancer. These are called diagnostic tests. Diagnostic tests may include a biopsy, in which cells ortissues are removed so a pathologist can check them under a microscope for signs of cancer.

Certain screening tests may be suggested only for people who have a high risk for certain cancers

Anything that increases the chance of cancer is called a cancer risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer.

Some screening tests are used only for people who have known risk factors for certain types of cancer. People known to have a higher risk of cancer than others include those who:

  • Have had cancer in the past; or
  • Have two or more first-degree relatives (a parent, brother, or sister) who have had cancer; or
  • Have certain gene mutations (changes) that have been linked to cancer.

People who have a high risk of cancer may need to be screened more often or at an earlier age than other people.

Breast Cancer Screening

General Information About Breast Cancer

Key Points

  • Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast;
  • Breast cancer is the second leading cause of death from cancer in women, in the World;
  • Different factors increase or decrease the risk of breast cancer.

Breast cancer is the second leading cause of death from cancer in the World in women

Women in Romania get breast cancer more than any other type of cancer except for skin cancer. Breast cancer is second only to lung cancer as a cause of cancer death in women. Breast cancer occurs more often in white women than in black women. However, black women are more likely than white women to die from the disease. Breast cancer occurs in men also, but the number of cases is small.

Different factors increase or decrease the risk of breast cancer

Anything that increases your chance of getting a disease is called a risk factor. Anything that decreases your chance of getting a disease is called a protective factor.

Tests are used to screen for different types of cancer

Some screening tests are used because they have been shown to be helpful both in finding cancers early and in decreasing the chance of dying from these cancers. Other tests are used because they have been shown to find cancer in some people; however, it has not been proven in clinical trials that use of these tests will decrease the risk of dying from cancer.

Scientists study screening tests to find those with the fewest risks and most benefits. Cancer screening trials also are meant to show whether early detection (finding cancer before it causes symptoms) decreases a person’s chance of dying from the disease. For some types of cancer, the chance of recovery is better if the disease is found and treated at an early stage.

Clinical trials that study cancer screening methods are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI website.

Risks of Breast Cancer Screening

Key Points

  • Screening tests have risks.
  • The risks of breast cancer screening tests include the following:
    • Finding breast cancer may not improve health or help a woman live longer;
    • False-negative test results can occur;
    • False-positive test results can occur;
    • Anxiety from additional testing may result from false positive results;
    • Mammograms expose the breast to radiation;
    • There may be pain or discomfort during a mammogram.
  • The risks and benefits of screening for breast cancer may be different in different age groups;
  • Talk to your doctor about your risk of breast cancer and your need for screening tests.

Screening tests have risks

Decisions about screening tests can be difficult. Not all screening tests are helpful and most have risks. Before having any screening test, you may want to discuss the test with your doctor. It is important to know the risks of the test and whether it has been proven to reduce the risk of dying from cancer.

The risks of breast cancer screening tests include the following:

Finding breast cancer may not improve health or help a woman live longer

Screening may not help you if you have fast-growing breast cancer or if it has already spread to other places in your body. Also, some breast cancers found on a screening mammogram may never cause symptoms or become life-threatening. Finding these cancers is called overdiagnosis. When such cancers are found, treatment would not help you live longer and may instead cause serious side effects. At this time, it is not possible to be sure which breast cancers found by screening will cause problems and which ones will not.

False-negative test results can occur

Screening test results may appear to be normal even though breast cancer is present. A woman who receives afalse-negative test result (one that shows there is no cancer when there really is) may delay seeking medical care even if she has symptoms.

One in 5 cancers may be missed by mammography. False-negative results occur more often in younger women than in older women because the breast tissue of younger women is more dense. The chance of a false-negative result is also affected by the following:

  • The size of the tumor;
  • The rate of tumor growth;
  • The level of hormones, such as estrogen and progesterone, in the woman’s body;
  • The skill of the radiologist.

False-positive test results can occur

Screening test results may appear to be abnormal even though no cancer is present. A false-positive test result (one that shows there is cancer when there really isn’t) is usually followed by more tests (such as biopsy), which also have risks.

When a breast biopsy result is abnormal, getting a second opinion from a different pathologist may improve the accuracy of a breast cancer diagnosis. Most abnormal test results turn out not to be cancer.

False-positive results are more common in the following:

  • Younger women;
  • Women who have had previous breast biopsies;
  • Women with a family history of breast cancer;
  • Women who take hormones, such as estrogen and progestin.

The skill of the radiologist also can affect the chance of a false-positive result.

The risks and benefits of screening for breast cancer may be different in different age groups

The benefits of breast cancer screening may vary among age groups:

  • In women who are expected to live 5 years or fewer, finding and treating early stage breast cancer may reduce their quality of life without helping them live longer.
  • As with other women, in women older than 65 years, the results of a screening test may lead to morediagnostic tests and anxiety while waiting for the test results. Also, the breast cancers found are usually not life-threatening.
  • It has not been shown that women with an average risk of developing breast cancer benefit from starting screening mammography before age 40.

Women who have had radiation treatment to the chest, especially at a young age, are advised to have routine breast cancer screening. Yearly MRI screening may begin 8 years after treatment or by age 25 years, whichever is later. The benefits and risks of mammograms and MRIs for these women have not been studied.

There is no information on the benefits or risks of breast cancer screening in men. No matter how old you are, if you have risk factors for breast cancer you should ask for medical advice about when to begin having breast cancer screening tests and how often to have them.

Talk to your doctor about your risk of breast cancer and your need for screening tests

Talk to your doctor or other health care provider about your risk of breast cancer, whether a screening test is right for you, and the benefits and harms of the screening test. You should take part in the decision about whether you want to have a screening test, based on what is best for you.