Diagnostic chest x-rays and breast cancer risk before age 50 years for BRCA1 and BRCA2 mutation carriers

John EM, McGuire V, Thomas DC, Haile R, Ozcelik H, Milne RL, Felberg A, West DW, Miron A, Knight JA, Terry MB, Daly M, Buys SS, Andrulis IL, Hopper JL, Southey MC, Giles GG, Apicella C, Thorne H, Whittemore AS (2013) Diagnostic chest x-rays and breast cancer risk before age 50 years for BRCA1 and BRCA2 mutation carriers. Cancer Epidemiol Biomarkers Prev 22:1547-1556

Background: The effects of low-dose medical radiation on breast cancer risk are uncertain, and few studies have included genetically susceptible women, such as those who carry germline BRCA1 and BRCA2 mutations. Methods: We studied 454 BRCA1 and 273 BRCA2 mutation carriers aged <50 years="" from="" three="" breast="" cancer="" family="" registries="" in="" the="" usa,="" canada,="" and="" australia/new="" zealand.="" we="" estimated="" breast="" cancer="" risk="" associated="" with="" diagnostic="" chest="" x-rays="" by="" comparing="" mutation="" carriers="" with="" breast="" cancer="" (cases)="" with="" those="" without="" breast="" cancer="" (controls).="" exposure="" to="" chest="" x-rays="" was="" self-reported.="" mammograms="" were="" not="" considered="" in="" the="" analysis.="" results:="" after="" adjusting="" for="" known="" risk="" factors="" for="" breast="" cancer,="" the="" odds="" ratio="" (or)="" for="" a="" history="" of="" diagnostic="" chest="" x-rays,="" excluding="" those="" for="" tuberculosis="" or="" pneumonia,="" was="" 1.16="" (95%="" confidence="" interval="" (ci)="0.64-2.11)" for="" brca1="" mutations="" carriers="" and="" 1.22="" (95%="" ci="0.62-2.42)" for="" brca2="" mutations="" carriers.="" the="" or="" was="" statistically="" elevated="" for="" brca2="" mutation="" carriers="" with="" 3-5="" diagnostic="" chest="" x-rays="" (p="0.01)," but="" not="" for="" those="" with="" 6="" or="" more="" chest="" x-rays.="" few="" women="" reported="" chest="" fluoroscopy="" for="" tuberculosis="" or="" chest="" x-rays="" for="" pneumonia;="" the="" or="" estimates="" were="" elevated,="" but="" not="" statistically="" significant,="" for="" brca1="" mutation="" carriers.="" conclusions:="" our="" findings="" do="" not="" support="" a="" positive="" association="" between="" diagnostic="" chest="" x-rays="" and="" breast="" cancer="" risk="" before="" age="" 50="" years="" for="" brca1="" or="" brca2="" mutation="" carriers.="" impact:="" given="" the="" increasing="" use="" of="" diagnostic="" imaging="" involving="" higher="" ionizing="" radiation="" doses,="" further="" studies="" of="" genetically="" predisposed="" women="" are="">