(Refer to the PDQ summary on Breast Cancer Prevention for more information about factors that increase the risk of breast cancer.)
Protective factors and interventions to reduce the risk of female breast cancer include the following:
- Estrogen use (after hysterectomy).[56,57,58]
- Early pregnancy.[23,62,63]
- Breast feeding.
- Selective estrogen receptor modulators (SERMs).
- Aromatase inhibitors or inactivators.[66,67]
- Risk-reducing mastectomy.
- Risk-reducing oophorectomy or ovarian ablation.[69,70,71,72]
(Refer to the PDQ summary on Breast Cancer Prevention for more information about factors that decrease the risk of breast cancer.)
Clinical trials have established that screening asymptomatic women using mammography, with or without clinical breast examination, decreases breast cancer mortality. (Refer to the PDQ summary on Breast Cancer Screening for more information.)
When breast cancer is suspected, patient management generally includes the following:
- Confirmation of the diagnosis.
- Evaluation of the stage of disease.
- Selection of therapy.
The following tests and procedures are used to diagnose breast cancer:
- Breast magnetic resonance imaging (MRI), if clinically indicated.
Pathologically, breast cancer can be a multicentric and bilateral disease. Bilateral disease is somewhat more common in patients with infiltrating lobular carcinoma. At 10 years after diagnosis, the risk of a primary breast cancer in the contralateral breast ranges from 3% to 10%, although endocrine therapy decreases that risk.[73,74,75] The development of a contralateral breast cancer is associated with an increased risk of distant recurrence. When BRCA1 /BRCA2 mutation carriers were diagnosed before age 40 years, the risk of a contralateral breast cancer reached nearly 50% in the ensuing 25 years.[77,78]
Patients who have breast cancer will undergo bilateral mammography at the time of diagnosis to rule out synchronous disease. To detect either recurrence in the ipsilateral breast in patients treated with breast-conserving surgery or a second primary cancer in the contralateral breast, patients will continue to have regular breast physical examinations and mammograms.
The role of MRI in screening the contralateral breast and monitoring women treated with breast-conserving therapy continues to evolve. Because an increased detection rate of mammographically occult disease has been demonstrated, the selective use of MRI for additional screening is occurring more frequently despite the absence of randomized, controlled data. Because only 25% of MRI-positive findings represent malignancy, pathologic confirmation before treatment is recommended. Whether this increased detection rate will translate into improved treatment outcome is unknown.[79,80,81]