Management of Bilateral Malignant Breast Masses

Initial Workup and Staging

The National Comprehensive Cancer Network recommends a history and physical examination with focus on family history of breast cancer, genetic risk factors, and symptoms for patients with bilateral malignant breast masses 1, 3
Bilateral diagnostic mammography is recommended to identify the presence of multiple primary tumors and estimate extent of disease in patients with bilateral malignant breast masses 1, 3
Pathology review of both lesions, including determination of estrogen receptor (ER), progesterone receptor (PR), and HER2 status, is necessary for patients with bilateral malignant breast masses 3
Genetic counseling is recommended if the patient is considered high risk for hereditary breast cancer, particularly BRCA1/2 mutations given bilateral presentation 1, 2

The National Comprehensive Cancer Network recommends bilateral total mastectomy with axillary staging as the standard surgical approach for bilateral malignant breast masses 1, 2, 5
Complete axillary lymph node dissection should not be performed in the absence of evidence of invasive cancer or proven metastatic disease in patients with bilateral malignant breast masses 3
Sentinel lymph node biopsy is appropriate for staging the axilla when invasive cancer is present in patients with bilateral malignant breast masses 3, 4
Bilateral mastectomy should involve removal of all breast tissue (total mastectomy) in patients with bilateral malignant breast masses 5
Immediate breast reconstruction is an appropriate option and should be discussed with patients with bilateral malignant breast masses 1, 2, 5

Adjuvant treatment should be determined by tumor stage, hormone receptor status, and HER2 status of the more advanced lesion in patients with bilateral malignant breast masses 4
Axillary lymph node involvement should be considered when determining adjuvant treatment for patients with bilateral malignant breast masses 4

Annual examinations of the chest/reconstructed breast are recommended after bilateral mastectomy, as there remains a small risk of developing breast cancer 5
Mammograms are not recommended after bilateral mastectomy 5
Routine health maintenance with focus on surveillance for recurrence is necessary after bilateral mastectomy 5
Women with BRCA1/2 mutations should be monitored according to genetic/familial high-risk assessment guidelines and consider risk-reducing salpingo-oophorectomy 5

Definitive diagnosis with tissue biopsy should not be delayed, as this could result in delayed treatment of malignancy in patients with bilateral malignant breast masses 6
Unilateral mastectomy should not be performed when bilateral malignancy is confirmed, as the risk is equal in both breasts 1, 2
Genetic counseling should not be omitted in patients with bilateral breast cancer, as this presentation suggests possible hereditary cancer syndrome 1, 2, 5