Mammography: Breast Cancer Screening — Who Needs It and What to Expect

Mammography is a low-dose X-ray examination of the breasts used to detect early breast cancer — including invasive cancers and ductal carcinoma in situ (DCIS) — before they become palpable or cause symptoms. Early detection through mammography significantly improves treatment options, reduces the need for aggressive treatment, and increases survival rates. Multiple large randomised controlled trials have confirmed that regular mammography screening reduces breast cancer mortality by 15–25% in screened populations.

In Korea, the National Cancer Screening Program (NCSP), run through the National Health Insurance Service, offers routine mammography to women aged 40 and over every two years through NHIS-designated hospitals and clinics. Women with a strong family history of breast cancer (first-degree relative diagnosed under 50, or BRCA mutation carriers) may be offered earlier or more frequent screening. Diagnostic mammography — for investigation of breast symptoms such as a lump, pain, nipple discharge, or skin changes — is available on referral at any age.

The mammography procedure itself involves gentle compression of the breast between two plates while X-ray images are taken — typically two views per breast. Compression may be briefly uncomfortable but is important to spread tissue for better image quality and to reduce dose. Digital mammography and digital breast tomosynthesis (3D mammography) are the current standard, with tomosynthesis showing improved cancer detection in dense breast tissue. Results are reported by specialist radiologists — women with dense breast tissue may be advised that supplemental ultrasound or MRI screening provides additional benefit.