Breast Cancer Screening Guidelines



At the American Cancer Society, we know that detecting breast cancer early, at its most treatable stage, can make the difference between life and death. There are three keys to ensuring that breast cancer is caught early and improves a person’s chances of beating the disease:

Follow Screening Guidelines
The American Cancer Society’s published cancer screening guidelines are for people at average risk for cancer (unless otherwise specified) and without any specific symptoms. The Society’s current guidelines for the early detection of breast cancer are:

  • Yearly mammograms are recommended starting at age 40 and continuing for as long as a woman is in good health.
  • Clinical breast exam (CBE) should be part of a periodic health exam, about every 3 years for women in their 20s and 30s and every year for women 40 and over.
  • Women should know how their breasts normally look and feel and report any breast change promptly to their health care providers. Breast self-exam (BSE) is an option for women starting in their 20s.
  • Women at increased risk (for example, family history, genetic tendency, past breast cancer) should talk with their doctors about the benefits and limitations of starting mammography screening earlier, having additional tests (for example, breast ultrasound or MRI), or having more frequent exams.

Watch for Signs and Symptoms
The earliest sign of breast cancer is usually an abnormality detected on a mammogram before the woman or health care professional can feel it. Larger tumors may become noticeable as a breast lump, thickening, swelling, distortion, tenderness, skin irritation, dimpling, nipple pain, scaliness, ulceration, retraction, or spontaneous discharge. Usually, breast pain results from benign conditions and is not the first symptom of breast cancer. All suspicious lumps should be checked for a definitive diagnosis.

Know the Risk Factors
Aside from being female, age is the most important factor affecting breast cancer risk. About 77 percent of women who are diagnosed with breast cancer are age 50 or older. About 18 percent of breast cancer diagnoses are among women in their 40s. Risk is also increased by:

  • Inherited genetic mutations (BRCA1 and BRCA2)
  • A personal or family history of breast cancer
  • High breast tissue density (a mammographic measure of the amount of glandular tissue relative to fatty tissue in the breast)
  • Biopsy-confirmed hyperplasia (especially atypical hyperplasia)
  • High-dose radiation to the chest as a result of medical procedures
  • Reproductive factors including a long menstrual history (menstrual periods that start early and/or end late in life), never having children, recent use of oral contraceptives, postmenopausal hormone therapy, and having one's first child after age 30.

At this time, there is no guaranteed way to prevent breast cancer, which is why regular mammograms are so important. A woman’s best overall preventive health strategies, besides regular mammograms, are to:

  • Maintain a healthy body weight 
  • Engage in regular physical activity*
  • Reduce alcohol consumption to no more than one drink a day

People who are at increased risk for certain cancers may need to follow a different screening schedule, such as starting at an earlier age or being screened more often. Those with symptoms that could be related to cancer should see their doctor right away.

To learn more about breast cancer, please visit or call us toll-free at 1-800-ACS-2345, anytime day or night.

*A recent Journal of the American Medical Association (JAMA) study found that exercise improves survival in women with breast cancer. The study found that women with breast cancer who engaged in an amount of physical activity equivalent to walking one or more hours per week had better survival compared with those who exercised less than that or not at all.