Lay Summary: Bilateral mastectomies followed by standard adjuvant chemotherapy is the prevailing approach for bilateral breast cancer.
About 3% or breast cancers present with synchronous bilateral disease IBBC) and 11% are bilateral over the course of a patient’s lifetiime.Unlike unilateral breast cancer there are no clear treatment guidelines for BBC.In a recent retrospective review, thirty out of 1100 (2.7%) patients with breast cancer treated between 1993 and 2003 had BBC, of whom 20 patients had metachronous and 10 patients had synchronous BBC. Family history of breast cancer was present in five patients (16%) only. Contralateral breast cancer (CBC) was detected mammographically in three and by clinical examination in 27 patients. Most CBC patients had early-stage disease compared with the index side (73% versus 27%). Fifty-six out of 60 tumors were found to be invasive ductal carcinoma, and none of the patients had lobular carcinoma. Twenty-three patients had bilateral mastectomy, three had unilateral mastectomy and four had a combination of breast conservation and mastectomy. Sixteen patients had unilateral and six had bilateral adjuvant radiotherapy. All patients received adjuvant chemotherapy and/or hormonal therapy both for index and CBC based on the stage and hormone receptor status. At a median follow up of 31.5 months (3–142 months), 23 (76%) patients were disease free and seven (24%) patients had disease relapse. Mean overall survival of patients with MBBC was significantly longer than those with SBBC (30.4 months versus 19.2 months; P = 0.045).
Bilateral mastectomies, as opposed to breast conserving surgey is supported by a supposition that bilateral breast cancer is more agressive, but this is not universally accepted. however, in the absence of guidelines, there is sufficient literature support for bilateral mastectomies to consider it to be a standard of care approach. Bilateral mastectomies followed by adjuvant standard chemotherapy is the most common approach.
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J. J. Jobsen, J. van der Palen, F. Ong and J. H. Meerwaldt
Synchronous, bilateral breast cancer: prognostic value and incidence
The Breast, Volume 12, Issue 2, April 2003, Pages 83-88