Breast cancer mortality has improved in the past several decades in developed countries in large part due to increased breast cancer screening. Because it has an 85% sensitivity of detecting cancer, screening mammography has allowed clinicians to identify malignancies at an earlier size and stage when therapy is more likely to result in cure. Large series have confirmed that patients with screen-detected cancers have improved survival when compared to those with symptomatic cancers. The American Cancer Society and the American College of Obstetricians and Gynecologists agree that women over the age of 50 should undergo annual screening mammography. Screening between the ages of 40 and 50 is still the subject of some controversy but most experts agree that women aged 40–49 should undergo screening mammography every 1–2 years. Women with first-degree relatives with breast cancer younger than 50 should begin their annual screening mammography 10 years younger than the youngest woman in their family to be diagnosed and should be considered for genetic counseling. Because over 10 years of screening, 50% of women will be called back for additional imaging and 25% for tissue biopsies but less than 10% (or 3/10 patients undergoing breast biopsy) will be diagnosed with breast cancer, research into ever better breast screening modalities continues.

Breast MRI has an equal or better sensitivity to mammography in detecting breast cancer but is not very specific. The American Cancer Society and American College of Radiology recommend screening breast MRI only for patients at a lifetime risk of breast cancer of 20–25% or greater. The combined sensitivity and specificity of mammogram and MRI in high-risk women approaches 95%.

Clinical breast exam (CBE) by contrast has a 64% sensitivity of detecting cancer, self breast exam (SBE) 25%. Thus, while CBE continues to be an important part of women’s annual health maintenance, SBE has not been shown to increase cancer detection. SBE has been shown to raise anxiety while increasing detection of benign lesions.

To estimate a patient’s lifetime risk of breast cancer, several calculators are available: the Gail model, the Claus model and the NCI calculator. They incorporate patient’s age, family history, ethnicity, reproductive history, number of breast biopsies and number of atypical breast biopsies in varying degrees. However, it is important to counsel a patient that these are population risk indicators and are difficult to apply to individual patients. These models have been validated in only narrow populations of patients. Estimating a patient’s individual breast cancer risk as it changes over time remains difficult and is the subject of much research.

One of the most anxiety-provoking complaints a patient can bring to her physician is a palpable breast mass. In large series the incidence of breast cancer in a palpable mass has ranged from 15% to 60%. Therefore any palpable mass deserves a careful evaluation that includes physical examination, imaging and tissue biopsy.

A palpable mass that exhibits three dimensions and has a distinct texture different from the surrounding breast tissue should be documented by its clock face position (12:00 superior to the nipple, 6:00 inferior, etc.) and distance from the nipple. The mass’s texture (firm, soft, etc.) and size should also be included. Physical exam characteristics suspicious for underlying malignancy include skin tethering, erythema, fixation to underlying or overlying structures, new nipple inversion or retraction, associated nipple discharge and associated axillary lymphadenopathy and should be documented as well.