A mammogram is an x-ray picture of the breast. It can be used to check for breast cancer in women who have no signs or symptoms of the disease. It can also be used if you have a lump or other sign of breast cancer. Screening mammography is the type of mammogram that checks you when you have no symptoms.
Mammography (also called mastography) is the process of using low-energy X-rays (usually around 30 kVp) to examine the human breast, which is used as a diagnostic and screening tool. The goal of mammography is the early detection of breast cancer, typically through detection of characteristic masses and/or microcalcifications.
The use of mammography as a screening tool for the detection of early breast cancer in otherwise healthy women without symptoms is controversial.Keen and Keen indicated that repeated mammography starting at age 50 saves about 1.8 lives over 15 years for every 1,000 women screened. This result has to be seen against the negatives of errors in diagnosis, overtreatment, and radiation exposure. The Cochrane analysis of screening indicates that it is "not clear whether screening does more good than harm". According to their analysis one in 2,000 women will have her life prolonged by 10 years of screening, however, another 10 healthy women will undergo unnecessary breast cancer treatment. Additionally, 200 women will suffer from significant psychological stress due to false positive results.Newman points out that screening mammography does not reduce death overall, but causes significant harm by inflicting cancer scare and unnecessary surgical interventions.The Nordic Cochrane Collection notes that advances in diagnosis and treatment of breast cancer actually may make breast cancer screening no longer effective in decreasing deaths in breast cancer, and therefore no longer recommend routine screening for healthy women as the risks might outweigh the benefits.
The Cochrane Collaboration states that the best quality evidence does not demonstrate a reduction in mortality generally or a reduction in mortality from all types of cancer from screening mammography.The Canadian Task Force found that for women aged 50–69, screening 720 women once every 2–3 years for 11 years would prevent 1 death from breast cancer. For women age 40-49, 2100 women would need to be screened at the same frequency and period to prevent 1 death from breast cancer. Women whose breast cancer was detected by screening mammography before the appearance of a lump or other symptoms commonly assume that the mammogram "saved their lives".In practice, the vast majority of these women received no practical benefit from the mammogram.