At What Age Should Mammography Begin, and How Often Should It Be Done?

The most important strategy against cancer is early detection. Breast cancercan be successfully treated when detected early. Regular recommended screening is particularly important for this cancer, affecting almost one in every 8 women. Nevertheless, many women do not want regular screening and even consider it harmful.

In 2015, JAMApublished a meta-analysis of United States research between 2000 and 2014, comprising 3 large randomized studies examining benefits and harms of recommended screening for early breast cancer detection. Across age groups over 40, women undergoing mammography follow-up for 13 years had approximately %20 lower breast cancer mortality.

- What Is a Meta-Analysis? A meta-analysis combines results of multiple independent studies on a particular subject and statistically analyzes their findings. Meta-analysis results constitute the strongest scientific evidence.- 

A similar breast screening meta-analysis was reported in March 2018. Data from 2006-2011 in the Netherlands, involving women aged 50 to 70 diagnosed with breast cancer, totaling 72.612, showed %20 lower breast cancer mortality among regular screening attendees, particularly with mammography.

The same study also showed women not attending regular screening were 3 times more likely to have breast cancer detected at an advanced stage.

“However, mammography should not be perceived as preventing breast cancer. It can identify changes potentially leading to cancer years before breast cancer symptoms develop. Mammography is a valuable imaging method helping find cancer at an early stage, when treatment succeeds best, rather than advanced disease, thereby reducing mortality risk.”

Mammography also carries screening risks. Its most debated problem is finding something suspicious that proves harmless, potentially causing unnecessary biopsies, termed “overdiagnosis.” This occurs more often in women aged 40-45. After 45, its likelihood falls and the method is considered more reliable. Thus, whether to begin at 40 or 45 has been highly controversial.

Who Should Have Mammography Screening, at What Ages and for How Long?

For women without a breast cancer family history and at normal risk, the American Cancer Society (ACS) screening guideline is widely used worldwide.

Accordingly;

• Women at average breast cancer risk should begin mammography at 45.
• Women should nevertheless have the option of beginning at 40 if desired, with healthcare professionals' support. 
• Women aged 45 - 55 should have annual mammography; those without risk in regular screening by this age should be advised to switch to every 2 years when their doctor recommends it. 
• Women over 55 should retain the option of annual screening if desired. 
• Healthy women expected to live at least 10 more years should continue regular mammography.
• Screening breast examinations performed by doctors or recommended self-examinations are now no longer recommended.

According to the American Cancer Society (ACS), what are the criteria for high risk of breast cancer?

Discuss your family and personal medical history with your doctor. Generally, however,

• Women with breast cancer in a first-degree relative, such as mother, sister or daughter,
• Women with a known inherited mutation (BRCA1 or BRCA2),
• Women who, between ages 10 and 30, received chest radiotherapy treatment, and
• Women with a personal breast cancer history are at high risk of a second breast cancer. Those outside these groups are considered normal/average risk.

-Related topic: How Should People with Hereditary Breast Cancer Be Monitored and Treated?

When, How Often and by Which Method Should High-Risk Individuals Be Screened?

For high-risk individuals, breast MRI (magnetic resonance imaging) is recommended in addition to mammography, not instead of it. However, evidence supporting routine annual MRI is insufficient. MRI is particularly recommended for people with a personal history of breast cancer, ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS), atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), or breasts described on mammography as extremely or heterogeneously dense in their breast tissue.

-Related topic:  Breast Masses That Are Not Cancer but Increase Cancer Risk

High-risk women should decide when to begin screening after discussion with their doctor. For most, the recommended starting age is 30, using MRI and mammograms and continuing while healthy.

Why Did the ACS Change Routine Screening Start Age from 40 to 45?

Studies indicate lower cancer risk at ages 40-44 and slightly greater harm from suspicious false positives leading to overdiagnosis, so starting at 40 is unnecessary. The benefit-harm balance becomes more favorable after 45.

What Should a Woman Aged 40 Do?

For some women, breast cancer anxiety weighs more heavily. If they want to minimize missing a genuinely suspicious lesion detectable early by mammography, starting at 40 is acceptable. Discuss this concern and the most suitable approach with a doctor.

According to ACS, Why Switch from Annual Mammograms After 55 to Every 2 Years?

Although breast cancer is more common after menopause, tumors tend to grow more slowly then. Reduced breast density with age also makes detection easier. However, for women unwilling to screen every 2 years, annual screening after 55 remains another option.

Can Mammography Radiation Cause Cancer?

Mammography uses a special X-ray device capable of imaging at low radiation doses. Its main distinction from conventional X-rays is providing higher-quality images with lower doses.

Many studies suggest mammography radiation does not cause cancer. Some, however, suggest risk varies with frequency, dose and exposure duration. Obese women, those with large breasts or dense tissue may face higher exposure doses and potentially higher risk. Nevertheless, radiation-related breast cancer incidence and mortality associated with recommended screening strategies remain low compared with deaths from breast cancers unrelated to radiation.

According to ACS, Manual Breast Examination Is No Longer Recommended!

Clinical breast examination is performed by a doctor. Previously, women were also advised to examine themselves monthly and consult a doctor about suspicious lumps. The latest ACS guideline recommends stopping both clinical and self-examination for breast cancer screening.

Recent studies, contrary to older findings, show clinical examination contributes very little to early diagnosis, while combining palpation and mammography increases false suspicious lesions. Similarly, evidence shows monthly self-examination does not help reduce breast cancer deaths.

However, women noticing a visible abnormality or feeling a different formation in their breasts should always tell a doctor.

Although imperfect, mammography remains the most effective screening method for early breast cancer diagnosis. Regular mammography screening is a valuable tool for reducing breast cancer disease burden in women. 

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