- The biology and outcomes of bilateral breast cancer:
- Continue to be of interest, but the recommendations for optimal treatment are sometimes difficult
- Synchronous and metachronous bilateral breast cancers:
- Range from 1% to 20% of patients with breast cancer
- Improvements in screening and the increased use of MRI:
- Often diagnose more early-stage synchronous bilateral cancer
- Women with a history of breast cancer:
- Are at increased risk of a metachronous cancer:
- Improvements in survival necessitate continued screening for future contralateral cancers
- Historically, controversy existed as to whether all bilateral breast cancers were harbingers of an underlying genetic abnormality with worse recurrence rates and survival:
- However, most bilateral breast cancers are not caused by germline mutations such as BRCA:
- But may be associated with environmental factors or prolonged hormonal exposure
- However, most bilateral breast cancers are not caused by germline mutations such as BRCA:
- Are at increased risk of a metachronous cancer:
- Retrospective studies evaluating the outcomes of synchronous bilateral breast cancer are limited by small cohort sizes, differing definitions, and non-matched unilateral patients as controls
- Most retrospective studies show no differences in local recurrence or survival for bilateral breast cancers:
- Making bilateral breast-conserving treatment:
- A safe option for early-stage synchronous cancers
- Making bilateral breast-conserving treatment:
- Irvine et al:
- Showed that survival is based on the more advanced cancer and that the secondary cancer does not affect overall prognosis
- This study was able to match patients with comparable unilateral breast cancer patients and showed similar outcomes
- Newman et al:
- Also found that patients with bilateral cancer were more likely to have multicentric disease and a family history of breast cancer:
- But there was no difference in 5-year disease-free survival
- Also found that patients with bilateral cancer were more likely to have multicentric disease and a family history of breast cancer:
- However, another study that did not match patients also found no differences in local control or overall survival among unilateral, metachronous, and synchronous breast cancer patients on multivariate analysis:
- But found a greater risk of distant metastasis in the 47 patients with synchronous disease
- Advances in CT scan-based simulation for bilateral breast radiation:
- Have made bilateral radiation feasible for early-stage breast cancers
- Advanced cancers with extensive nodal involvement:
- Might pose a problem with overlapping internal mammary fields
- Understanding the interplay among competing risk factors,including a patient’s personal history, family history, the presence of a BRCA mutation, life expectancy, and tumor biology:
- Offers greater insight to managing this increasingly common entity
- References:
- Beinart G, Gonzalez-Angulo AM, Broglio K, et al. Clinical course of 771 patients with bilateral breast cancer: characteristics associated with overall and recurrence-free survival. Clin Breast Cancer. 2007;7(11):867-874.
- Heron DE, Komarnicky LT, Hyslop T, Schwartz GF, Mansfield CM. Bilateral breast carcinoma: risk factors and outcomes for patients with synchronous and metachronous disease. Cancer. 2000;88(12):2739-2750.
- Intra M, Rotmensz N, Viale G, et al. Clinicopathologic characteristics of 143 patients with synchronous bilateral invasive breast carcinomas treated in a single institution. Cancer. 2004;101(5):905-912.
- Irvine T, Allen DS, Gillett C, Hamed H, Fentiman IS. Prognosis of synchronous bilateral breast cancer. Br J Surg. 2009;96(4):376-380.
- Newman LA, Sahin AA, Cunningham JE, et al. A case-control study of unilateral and bilateral breast carcinoma patients. Cancer. 2001;91(10):1845-1853. Erratum in: Cancer. 2002;94(4):1191.
Rodrigo Arrangoiz MS, MD, FACS, FSSO 