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Patient education: Breast cancer screening (Beyond the Basics)

Patient education: Breast cancer screening (Beyond the Basics)
Author:
Joann G Elmore, MD, MPH
Section Editor:
Mark D Aronson, MD
Deputy Editor:
Jane Givens, MD, MSCE
Literature review current through: Nov 2022. | This topic last updated: Mar 29, 2021.

INTRODUCTION — The goal of breast cancer screening is to detect breast cancer at an early stage, before a person discovers a lump. Breast cancer is more easily treated and more likely to be cured when it is caught earlier. The chance of dying from breast cancer has declined over the past few decades. While the majority of this drop in deaths due to breast cancer is thought to be due to improvements in treatment, an important part of the drop in deaths is also likely due to the use of breast cancer screening to find cancer at an earlier stage.

Screening for breast cancer involves mammography. This article describes what a mammography examination (also called a "mammogram") is like, the potential benefits and harms of screening, when to consider starting and stopping mammography, and how often to be screened. This article discusses breast cancer screening for people who are at average risk (the majority of people). The guidance for people with a high risk of breast cancer, such as those with a mutation in the BRCA1 or BRCA2 gene and those who have multiple close relatives with breast cancer, may be different. More information for people at higher risk is available separately. (See "Patient education: Factors that affect breast cancer risk in women (Beyond the Basics)" and "Patient education: Genetic testing for hereditary breast, ovarian, prostate, and pancreatic cancer (Beyond the Basics)".)

MAMMOGRAPHY

Getting a mammogram — A mammogram (“mammography”) is a breast X-ray. It is the best screening test for detecting breast cancer at an early stage.

Before the mammogram, you will be asked to undress from the waist up and wear a hospital gown or cape. Each breast is X-rayed individually. The breast is flattened between two panels. This can be uncomfortable, but it only takes a few seconds. If you still get a monthly period and your breasts are sensitive before or during your period, try to avoid scheduling your mammogram during that time if possible. Also, do not use underarm deodorant or powder on the day of your appointment; if you forget and do apply deodorant, you can request a special wipe to remove deodorant before the mammogram.

Mammogram results — A radiologist will review and interpret your mammogram. After the radiologist reviews your mammogram, you should get a phone call or letter with your results within 30 days. If you do not hear back about your results, call the office or hospital where you had the mammogram, or your doctor or nurse's office, rather than assuming that your mammogram was normal.

What if my mammogram is abnormal? — If your mammogram is abnormal, you will likely need further testing. In fact, in the United States, about 1 in every 10 people who are screened will have an abnormal mammogram requiring follow-up. Most often when this happens, you will need to have more images taken (either mammogram or ultrasound images). Needing more images is common and does not usually mean that you have cancer. Knowing that this is common may help to reduce your anxiety if this happens to you. The extra images help the radiologist to have the most accurate and clear view of your breast tissue. Occasionally, additional testing such as a breast biopsy (in which a small amount of tissue is removed for examination) is needed to follow up on an abnormal screening mammogram result.

Follow-up testing after an abnormal mammogram is discussed in more detail separately. (See "Patient education: Common breast problems (Beyond the Basics)", section on 'Abnormal mammogram'.)

What if my mammogram is normal but I feel a lump? — Some breast cancers cannot be seen on a mammogram. So it is possible to still have breast cancer even if your mammogram comes back “normal.” For this reason, it's still important to let your health care provider know right away if you notice a lump in your breast or have any other concerns about your breasts.

BREAST CANCER SCREENING GUIDANCE

When to start mammograms — Your decision about whether or not to have a mammogram and when to start should be based on your personal values and preferences, with input from your health care provider about the risks and benefits. Generally speaking, the benefit of screening is that a mammogram can detect breast cancer early, when it is more likely to be treatable. However, there are also drawbacks to screening. For example, there can be "false positives" (when test results suggest cancer and lead to additional testing that ultimately finds no cancer). There is also the possibility that screening may detect a cancer that is so slow growing it may never cause health problems or become life-threatening; treatment of these cancers (such as surgery, radiation treatment, or chemotherapy) can cause serious side effects and may not lead to a longer, healthier life.

As breast cancer is less common in younger people, the drawbacks of screening may outweigh the benefits for people under age 50.

You should be involved in making the decision of whether or not you want to have screening and, if so, when to start. For people at average risk, meaning those who do not have a gene that increases their risk of breast cancer or close relatives who had breast cancer at an early age, expert groups differ in their advice about when to actually start screening. If you are at average risk, you should start discussing breast cancer screening with your health care provider once you turn 40. Your health care provider might recommend starting regular mammograms at age 40, 45, or 50. Again, the recommendations for screening may be different for people who are at higher risk for developing breast cancer.

Can I have screening after I've gotten the COVID-19 vaccine? — Yes, but your doctor might recommend not scheduling them close together.

Some people have had temporary swelling of lymph nodes in the armpit (“axillary”) area after getting certain COVID-19 vaccines. In some cases, this can make it harder for the radiologist to interpret your mammogram. For this reason, experts recommend trying to schedule your mammogram either before you get the COVID-19 vaccine, or at least four to six weeks after your last dose.

If you’re not sure when to schedule your mammogram, talk to your health care provider. They can help you make this decision based on your situation. While breast cancer screening is important, it is also very important to get the COVID-19 vaccine when you are able.

How often to have a mammogram — It is not clear what the ideal schedule for screening should be. Many experts suggest mammograms every two years for most people at average risk. Other experts suggest mammograms every year. Some adjust the frequency depending on age. Again, the recommendations for screening may be different for people who are at higher risk for developing breast cancer. Your risk factors and preferences are important in determining how often you want to have a mammogram. (See "Patient education: Factors that affect breast cancer risk in women (Beyond the Basics)".)

When to stop mammograms — There are fewer data on screening mammography after the age of 75. Most expert groups recommend continuing routine screening mammograms in people who are expected to live at least 10 more years. People who have a lot of serious medical conditions that limit lifespan are not likely to benefit from screening mammography.

OTHER SCREENING METHODS BEYOND MAMMOGRAMS — Other approaches that may sometimes have a role in screening include imaging tests other than mammography. However, these methods are not typically recommended as part of screening for people who are at average risk for breast cancer.

Breast examination by your doctor or nurse — Most expert groups no longer recommend that clinicians perform breast exams as part of screening. Physical exams are not as accurate as mammography in detecting breast cancer. Your clinician will likely perform a breast examination if you tell them you have a new breast symptom or abnormality.

Breast self-examination — Most expert groups also no longer recommend monthly self-exams for breast cancer screening. No study has shown that breast self-exams reduce the risk of dying from breast cancer. Checking your breasts regularly for changes and abnormalities actually increases the chance of needing an unnecessary breast biopsy, which can be associated with increased anxiety, expense, and pain. Therefore, most expert groups no longer recommend monthly self-exams. However, some people feel that doing breast self-exams on a regular basis improves their ability to find changes that would otherwise not have been noticed. Some experts also encourage breast "self-awareness," which includes education about risk factors for breast cancer, developing an awareness of what is "normal" for you, and knowing what to do if you do notice a change in your breast.

Other imaging methods — Although other imaging methods like magnetic resonance imaging (MRI) and ultrasound can detect breast cancer, mammography is the only imaging method studied for screening average-risk people that has been found to be associated with decreased death from breast cancer. For this reason, only mammography is recommended as a screening test for the general population of women who are at average risk for developing breast cancer. However, breast MRI and ultrasound may be recommended for screening (in addition to mammography) for some high-risk groups. (See "Patient education: Genetic testing for hereditary breast, ovarian, prostate, and pancreatic cancer (Beyond the Basics)" and "Patient education: Factors that affect breast cancer risk in women (Beyond the Basics)".)

Breast ultrasound — A breast ultrasound is also not recommended as a routine screening test for people at average risk for breast cancer. Studies have shown that people who are screened with both mammograms and ultrasound tests are more likely to be referred for unnecessary breast biopsies, and so the benefit of adding ultrasound to mammography is not clear.

People with dense breasts (a term used to describe the appearance of the breast tissue on imaging) are at a slightly increased risk of breast cancer. If a mammogram shows that your breasts are very dense, this may make it more difficult for the radiologist to interpret a screening mammogram. In this situation, an ultrasound may be suggested in addition to mammography. However, there are no available studies showing that ultrasound screening for people with dense breast tissue will actually reduce the risk of dying of breast cancer.

Breast MRI — MRI uses a strong magnet (rather than X-rays) to create a detailed image. Breast MRI may be recommended, in addition to mammography, to help find breast cancer in people with a very high risk for developing breast cancer (such as those with a very strong family history of breast cancer, or a genetic mutation like BRCA1 or BRCA2). However, breast MRI is not recommended for routine screening in people who do not have a high risk of breast cancer. Compared with mammograms, breast MRI is associated with more "false-positive" findings (changes that turn out not to be cancer), may lead to more unnecessary biopsies, requires intravenous contrast (dye injected into the veins), and is more expensive.

WHERE TO GET MORE INFORMATION — Your health care provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Breast cancer screening (The Basics)
Patient education: Breast cancer (The Basics)
Patient education: Cancer screening (The Basics)
Patient education: Common breast problems (The Basics)
Patient education: Genetic testing for breast, ovarian, prostate, and pancreatic cancer (The Basics)
Patient education: Breast reconstruction after mastectomy (The Basics)
Patient education: Choosing surgical treatment for early-stage breast cancer (The Basics)
Patient education: Ductal carcinoma in situ (DCIS) (The Basics)
Patient education: Sentinel lymph node biopsy for breast cancer (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Genetic testing for hereditary breast, ovarian, prostate, and pancreatic cancer (Beyond the Basics)
Patient education: Common breast problems (Beyond the Basics)
Patient education: Factors that affect breast cancer risk in women (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Breast imaging for cancer screening: Mammography and ultrasonography
Clinical manifestations, differential diagnosis, and clinical evaluation of a palpable breast mass
Factors that modify breast cancer risk in women
Genetic testing and management of individuals at risk of hereditary breast and ovarian cancer syndromes
Overview of hereditary breast and ovarian cancer syndromes associated with genes other than BRCA1/2
Screening for breast cancer: Strategies and recommendations

The following organizations also provide reliable health information:

National Cancer Institute

1-800-4-CANCER

(https://www.cancer.gov/types/breast/patient/breast-screening-pdq)

National Library of Medicine

(https://medlineplus.gov/mammography.html)

Breast Screen Australia

(www.health.gov.au/initiatives-and-programs/breastscreen-australia-program)

ACKNOWLEDGMENT — The editorial staff at UpToDate would like to acknowledge Suzanne W Fletcher, MD, who contributed to an earlier version of this topic review.

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This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider's examination and assessment of a patient's specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms ©2023 UpToDate, Inc. and its affiliates and/or licensors. All rights reserved.
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