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Medline ® Abstract for Reference 51

of 'Prevalence of BRCA1 and BRCA2 mutations and associated cancer risks'

Population-based study of the risk of second primary contralateral breast cancer associated with carrying a mutation in BRCA1 or BRCA2.
Malone KE, Begg CB, Haile RW, Borg A, Concannon P, Tellhed L, Xue S, Teraoka S, Bernstein L, Capanu M, Reiner AS, Riedel ER, Thomas DC, Mellemkjaer L, Lynch CF, Boice JD Jr, Anton-Culver H, Bernstein JL
J Clin Oncol. 2010;28(14):2404. Epub 2010 Apr 5.
PURPOSE: Women with breast cancer diagnosed early in life comprise a substantial portion of those tested for BRCA1/BRCA2 mutations; however, little information is available on the subsequent risks of contralateral breast cancer in mutation carriers. This study assessed the risk of subsequent contralateral breast cancer associated with carrying a BRCA1 or BRCA2 mutation.
PATIENTS AND METHODS: In this nested case-control study, patients with contralateral breast cancer diagnosed 1 year or more after a first primary breast cancer (n = 705) and controls with unilateral breast cancer (n = 1,398) were ascertained from an underlying population-based cohort of 52,536 women diagnosed with a first invasive breast cancer before age 55 years. Interviews and medical record reviews were used to collect risk factor and treatment histories. All women were tested for BRCA1/BRCA2 mutations. Relative (rate ratios) and absolute (5- and 10-year cumulative) risks of developing contralateral breast cancer following a first invasive breast cancer were computed.
RESULTS: Compared with noncarriers, BRCA1 and BRCA2 mutation carriers had 4.5-fold (95% CI, 2.8- to 7.1-fold) and 3.4-fold (95% CI, 2.0- to 5.8-fold) increased risks of contralateral breast cancer, respectively. The relative risk of contralateral breast cancer for BRCA1 mutation carriers increased as age of first diagnosis decreased. Age-specific cumulative risks are provided for clinical guidance.
CONCLUSION: The risks of subsequent contralateral breast cancer are substantial for women who carry a BRCA1/BRCA2 mutation. These findings have important clinical relevance regarding the assessment of BRCA1/BRCA2 status in patients with breast cancer and the counseling and clinical management of patients found to carry a mutation.
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98006, USA. kmalone@fhcrc.org