Breast cancer screening looks for signs of cancer before a woman has symptoms. Screening can help find breast cancer early when it's most treatable. Two tests are commonly used to screen for breast cancer:Mammogram: A safe, low-dose x-ray exam of the breasts to look for changes that are not normal. Starting at age 40, women should have screening mammograms every 1-2 years. Depending on factors such as family history and your general health, your doctor may recommend a mammogram before age 40. Clinical breast exam (CBE): The doctor looks at and feels the breasts and under the arms for lumps or anything else that seems unusual. Ask your doctor if you need a CBE.
Regular screening is the best way to find breast cancer early in most women. If you are at higher risk you may need mammograms at an earlier age or more often. Or, your doctor might want to use other tests too, such as a different type of mammogram or magnetic resonance imaging (MRI).
It is important to let your doctor know if you find any changes in your breast, such as a lump or dimpling or puckering of the skin. While research data does not support an official recommendation that all women conduct breast self-exams, knowing your body is key to pointing out any concerns to your doctor.
This answer is based on source information from National Women's Health Information Center.