Breast Cancer Screening Guidelines

By Ajay Bhatnagar, MD, MBA

Over the past 13 years in Casa Grande, I have treated hundreds of breast cancer patients.  Since it is National Breast Cancer Awareness Month, I thought it would be good to review breast cancer screening guidelines.  Guidelines continue to evolve, so it is important to understand a woman’s risk of developing breast cancer, as well as how often screening should occur.

Breast cancer is the most frequent type of non-skin cancer and the second most frequent cause of cancer death in women in the United States.  Recommendations for breast cancer screening are a bit complicated, taking into account the risk of developing breast cancer.  Thus, guidelines are customized depending on the risk group a woman would be classified under.

Below are some factors I use to determine a risk category, based on a patient’s history:

  • Personal history of breast or gynecological cancer
  • Family history of breast or gynecological cancer
  • Ancestry associated with genetic mutations such as BRCA1or 2 mutations
  • Previous breast biopsy indicating a high-risk lesion
  • Radiotherapy to the chest between age 10 and age 30 (usually seen with treatment for Hodgkin’s lymphoma)

Women who have none of these risk factors are usually considered average risk.  My recommendations below are based on a woman with average risk only.  If a woman has any of the above risk factors, it is important to discuss screening with her physician as the protocol will be different.  Mammography (digital or film) is the primary modality for breast cancer screening in average-risk women.  Ultrasound and magnetic resonance imaging (MRI), are reserved for further evaluation of findings on mammography or for screening of women at a higher risk for breast cancer.  Breast examination by the clinician or by the patient is not recommended as the only screening method.

  • Age under 40— I suggest not screening average-risk women who are under 40 years of age since the incidence of breast cancer is very low.
  • Age 40 to 49— I encourage shared decision-making for women in their 40s because of trade-offs between benefits and harms.  For women who decide to initiate screening in their 40s, I typically suggest screening mammography every two years.  Expert guidelines vary in their recommendations about when to initiate screening and how frequently to screen average-risk women in the 40 to 49 age group.
  • Age 50 to 74— I suggest breast cancer screening every two years with mammography for average-risk women aged 50 to 74 years. This is consistent with most expert groups.  Multiple randomized trials over the past 50 years found that mammogram screening for women aged 50 to 70 decreases the risk of breast cancer death.
  • Age 75 and older— I only suggest that women over the age of 74 be offered screening if they are in excellent health.  The usual protocol is a mammogram every two years.