box-95Experts generally agree that the earlier a breast cancer is found, the better the prognosis is for a positive outcome. When a suspicious abnormality is found, the doctor will usually recommend additional tests such as additional mammographic views, ultrasound or a breast biopsy (taking a sample of the abnormal tissue for further study). More than 95% of breast biopsies can be performed in a breast imaging setting without general anesthesia or a surgical incision. Also, don’t panic, approximately 80% of breast lumps turn out to be benign.


Risks, potential harms and overall value of mammography and other screening tests

Mammography is not perfect, but it is currently the most studied and the most commonly used screening technology available. A decision-aid for women aged 40 to 49 has been created by experts at the Memorial Sloan Kettering Cancer Center ( As new research findings, new tests, new technology and new treatments become available. it is important for women (and men) and their doctors to have regular, comprehensive discussions about the benefits, limitations and potential harms of screening tests, the risks of not being screened, and the importance of observing the changes in one’s body. Some of the potential risks and harms of regular screening tests for breast cancer include:

box-perspectiveFalse-Negative Results: A false-negative is when the mammogram or other test fails to find an existing cancer. This is especially an issue for women with dense breasts.

False-Positive Results: A false-positive is when the mammogram or other test finds an abnormality that requires more tests to determine if the abnormality is cancerous or not. A false-positive means that there is no cancer. Potential harm includes increased worry and stress to the patient, exposure to additional imaging tests or a biopsy.

Over Diagnosis and Over Treatment: Not all breast cancers are aggressive or have the potential to be life-threatening. Improvements in screening are enabling doctors to find many cancers at very early stages. Unfortunately, science cannot currently tell which cancers detected and treated early would have otherwise progressed, and which will pose no further threats. Therefore, doctors often recommend treating most cancers aggressively. This situation can lead to “over diagnosis,” which carries the harm of “over treatment.” Over treatment includes exposure to unnecessary surgery, chemotherapy, radiation or other treatments for a cancer that was not life threatening. Current scientific knowledge does not allow us to know which cancers would not require such aggressive treatments. If cancer is found, seeking more than one medical opinion is recommended.

Sources & Resources

  1. Society, A.C., Breast Cancer Facts & Figures 2013-2014. 2013.
  2. Hunt, B.R., S. Whitman, and M.S. Hurlbert, Increasing Black:White disparities in breast cancer mortality in the 50 largest cities in the United States. Cancer Epidemiol, 2014. 38(2): p. 118-23.
  3. Wild, B.W.S.a.C.P., World Cancer Report 2014 2014.
  4. Ross, A.C., et al., The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab, 2011. 96(1): p. 53-8.
  5. Silverstein, M.J., et al., Special report: Consensus conference III. Image-detected breast cancer: state-of-the-art diagnosis and treatment. J Am Coll Surg, 2009. 209(4): p. 504-20.

This website was created for educational purposes only and should not be interpreted as medical advice. Be sure to partner with your medical provider to develop the best personal care plan for you. Adapted from the American Cancer Society, 2013-2014 Breast Cancer Facts & Figures.