Jewish religion and risk of breast cancer
Authors: Paolo G Toniolo, Ikuko Kato
Journal: The Lancet (1996)

Jews of Ashkenazim descent seem to be more likely than other groups in the US population to carry mutations in the BRCA1 and BRCA2 genes, and they may be unusually predisposed to breast cancer.1Futreal PA Liu Q Shattuck-Eidens et al.BRCA1 mutations in primary breast and ovarian carcinomas.Science. 1994; 266: 120-124Crossref PubMed Scopus (1145) Google Scholar, 2Wooster R Bignell G Lancaster J et al.Identification of the breast cancer susceptibility gene.BRCA2. Nature. 1995; 378: 789-792Crossref PubMed Scopus (2987) Google Scholar One would expect Ashkenazi Jews with a family history of breast cancer to be at much greater risk of the disease than women with a different genetic background. Consistent with this hypothesis, Egan and colleagues (June 15, p 165),3Egan KM Newcomb PA Longnecker MP et al.Jewish religion and risk of breast cancer.Lancet. 1996; 347: 1645-1646Summary PubMed Scopus (42) Google Scholar in a large case-control study, found almost a four-fold increase in the risk of breast cancer among Jewish women with a first-degree relative as compared with Catholic women without a family history of this disease. The New York University Women's Health Study is a prospective cohort study of 14 275 middle-aged women, 44% of Jewish origin, who were enrolled between 1985 and 1991 during mammographic screening in New York City.4Toniolo P Levitz M Zeleniuch-Jacquotte A et al.A prospective study of endogenous estrogens and breast cancer in postmenopausal women.J Natl Cancer Inst. 1995; 87: 190-197Crossref PubMed Scopus (585) Google Scholar Analyses reported here (see table) are limited to the 10 273 women who reported religious upbringing. As compared with Catholic women without a family history, the relative risk for breast cancer among Jewish women with first-degree family history was 1·69 (95% CI 1·16–2·45), and was marginally higher than among women with family history and different religion. We observed only a modest further increase in relative risk to 2·33 (1·35–4·02) in analyses limited to women aged 50 or younger, and we found no association among women aged 51 or more.TableRelative risk (RR and 95% CI) of breast cancer, according to religion and first-degree family history of breast cancerReligionNo family historyPositive family historyCases; non-casesRR*Cox's proportional hazard model adjusted for age, parity, age at first full-term pregnancy, age at menarche, menopausal status, height-adjusted weight (Quetelet index), and previous breast biopsy.Cases, non-casesRR*Cox's proportional hazard model adjusted for age, parity, age at first full-term pregnancy, age at menarche, menopausal status, height-adjusted weight (Quetelet index), and previous breast biopsy.All agesCatholic71; 24541·024; 5561·36 (0·85–2·15)Protestant49; 16961·00 (0·70–1·45)15; 3611·38 (0·79–2·40)Jewish140; 34541·26 (0·94–1·69)47; 8131·69 (1·16–2·45)Other12; 4680·95 (0·51–1·75)5; 782·12 (0·85–6·25)Age ≤50Catholic33; 12861·015; 2581·96 (1·06–3·61)Protestant21; 9270·84 (0·49–1·45)7; 1841·38 (0·61–3·12)Jewish34; 11900·97 (0·60–1·58)22; 3042·33 (1·35–4·02)Other5; 2910·70 (0·27–1·80)2; 362·03 (0·49–8·49)* Cox's proportional hazard model adjusted for age, parity, age at first full-term pregnancy, age at menarche, menopausal status, height-adjusted weight (Quetelet index), and previous breast biopsy. Open table in a new tab Our findings confirm suggestions of an increased risk of breast cancer among Jewish-American women (predominantly Ashkenazim) who have a first-degree family history of breast cancer but the association was much weaker than that reported by Egan and colleagues. The lower relative risk we found might reflect to some extent our choice of study population. Women seeking mammographic screening, as expected, reported a first-degree family history with a higher frequency than Egan and colleagues' patients did (18·6% vs 13·0% among non-cases, respectively). Our data do not suggest that Jewish religion per se is an especially important risk factor for breast cancer.