Breast Cancer Screening
Breast cancer is one of the most common cancers with a high mortality rate among women. Screening via mammography helps detect breast cancer at an early stage.
What Is a Mammogram?
A mammogram, or breast X-ray (mammography), is a technique that uses low-dose X-rays to create images of breast tissue. It is a rapid, effective, non-invasive, and cost-efficient method for breast cancer screening.
Screening differs from diagnosis: screening is intended for women without symptoms to detect cancer early. If you experience symptoms such as a newly formed lump, abnormal nipple discharge, nipple retraction, or skin changes on the breast, you should seek medical evaluation immediately for diagnostic assessment.
1. Benefits of Mammography Screening
Early Cancer Detection: Screening helps detect breast cancer when lesions are still small, increasing the likelihood of a cure and reducing the need for aggressive treatments.
Reduced Mortality Risk: Mammography is the most effective tool for breast cancer screening, as studies demonstrate that annual mammographic screening can reduce breast cancer mortality by up to 40%.
Increased Opportunity for Effective Treatment: Detecting cancer while it is small and localized provides patients with more treatment options and significantly improves survival prognoses.
2. Target Audience for Screening
Not all women share the same risk for breast cancer. Age, family history, genetic factors, treatment history, and breast tissue characteristics all influence disease risk and screening strategies. Therefore, screening should be personalized based on individual risk.
Average-Risk Women
This group includes women without significant risk factors for breast cancer, such as no high-risk gene mutations, no history of chest radiation therapy at a young age, and no strong family history suggesting hereditary risk.
According to recommendations from the ACR and SBI, average-risk women should begin annual mammography screening at age 40 to maximize the benefits of early detection. Some other professional societies suggest screening intervals can be extended to every 2 years.
Screening should continue as long as a woman is in good health and has a life expectancy long enough to benefit from early detection, unless severe underlying health conditions significantly shorten life expectancy. Therefore, age alone should not be the sole reason to discontinue screening.
High-Risk Women
Certain women face a significantly higher risk of breast cancer compared to the general population if they possess at least one of the following factors:
Carrying gene mutations that increase breast cancer risk, particularly BRCA1, BRCA2, and other high-risk genes.
A strong family history, such as multiple relatives diagnosed with breast or ovarian cancer, particularly at a young age.
High-risk breast lesions identified via biopsy, such as atypical ductal hyperplasia (ADH) or lobular carcinoma in situ (LCIS).
A history of chest radiation therapy at a young age, particularly during childhood or adolescence.
A lifetime breast cancer risk of approximately 20% to 25% or greater based on validated risk assessment models.
High-risk groups should undergo risk evaluation early, ideally around age 25, to establish an appropriate screening plan. Depending on the cause and risk level, screening typically begins around ages 25–30 or 10 years younger than the youngest affected relative's age at diagnosis.
For high-risk women, screening generally combines mammography with breast magnetic resonance imaging (MRI). According to many recommendations, these two modalities can be performed alternately—for instance, spaced approximately 6 months apart—to increase the likelihood of detecting cancer in the interval between regular screenings.
Women with Dense Breasts
Breast density reflects the proportion of glandular and fibrous tissue relative to fatty tissue in the breast. Breasts are considered dense when they have a high proportion of glandular and fibrous tissue compared to fat. Dense breast tissue is common, affecting about half of all women, especially Asian women.
Dense breasts have two major implications for breast cancer screening. First, women with dense breasts face a higher risk of developing breast cancer compared to those with non-dense breasts. Second, dense tissue significantly obscures lesions on mammograms, reducing the sensitivity for cancer detection.
Consequently, some women with dense breasts may be considered for supplemental screening alongside routine mammography. Methods available include breast ultrasound, breast MRI, or contrast-enhanced mammography (CEM). The necessity of supplemental screening should be determined based on breast density level and overall individual breast cancer risk.
Transgender Individuals
Breast cancer risk in transgender individuals depends on various factors, including hormone use, surgical history, family history, and other risk factors.
Transfeminine Individuals: Those who have used hormone therapy for 5 years or more should undergo annual mammography screening starting at age 40.
Transmasculine Individuals: If they have not undergone bilateral total mastectomy or if residual breast tissue remains post-surgery, they should also undergo annual mammography screening starting at age 40.
If a transgender individual is assessed to have an above-average risk for breast cancer, earlier and more intensive screening protocols similar to high-risk biological females should be considered.
3. Mammography Procedure
The basic steps of performing a mammogram include:
Preparation: The patient removes outer garments, undergarments, and jewelry, and changes into a specialized hospital gown.
Breast Positioning and Compression: The technologist will guide the patient to place one breast on the machine platform. A clear plastic paddle will then gently compress the breast to immobilize it and capture the image. The procedure is then repeated for the other breast.
Image Interpretation: Images are uploaded to the system, where a radiologist reads the results and analyzes any potential abnormalities.
4. Important Considerations During Mammography
Do not apply powders, deodorants, perfumes, ointments, or lotions to the chest or underarm areas, as these can create artifacts on images that radiologists might misinterpret as lesions.
If you are pregnant or breastfeeding, inform your healthcare provider to receive guidance on appropriate testing methods.
If you have breast implants or have received chest fillers, notify medical staff in advance so specialized mammography techniques can be applied.
The optimal time for mammography is 1 week after the start of your menstrual period. Avoid scheduling mammograms during the week prior to your period, as breasts tend to be swollen and tender, causing increased discomfort during compression and hindering lesion detection.
A mammogram typically takes about 10 to 15 minutes.
5. References
- Monticciolo, Debra L., et al. "Breast cancer screening recommendations inclusive of all women at average risk: update from the ACR and Society of Breast Imaging." Journal of the American College of Radiology 18.9 (2021): 1280-1288.
- US Preventive Services Task Force. Screening for Breast Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2024;331(22):1918–1930. doi:10.1001/jama.2024.5534.
- American College of Radiology (ACR) / Society of Breast Imaging (SBI). Recommendations for annual mammographic screening beginning at age 40 for women at average risk.
- American College of Radiology. Breast Cancer Screening in Women at Higher-Than-Average Risk. Recommendations for MRI and mammography in women at increased risk.
- National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Breast Cancer Screening and Diagnosis. Version 2026.
The information above is for reference purposes only and is not intended as medical advice. Please contact your doctor for detailed medical consultation.