Twin studies suggest a familial aggregation of bladder cancer but elements of this increased familial risk of bladder cancer are not well understood. To characterize familial risk of bladder cancer, we examined the relationship between family history of bladder and other types of cancer among first-degree relatives and risk of bladder cancer in 1,193 bladder cancer cases and 1,418 controls in a large population-based case-control study. Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between family history of bladder cancer (defined as at least one first degree family member with bladder cancer or a cancer of any other site). We also evaluated cancer aggregation of specific sites in family members. Participants with a first degree relative with bladder cancer had nearly double the risk of bladder cancer (OR=1.8, 95% CI:1.2, 2.9) as those without a family history of bladder cancer. Risk was increased for having a sibling with bladder cancer (OR=2.6, 95% CI:1.3, 5.3) compared to no siblings with cancer. Bladder cancer risk was elevated when participants reported a first-degree relative with a history of female genital cancer (OR=1.5, 95% CI:1.1, 2.1), melanoma (OR=1.9, 95%CI:1.02, 3.6), and tobacco-associated cancer (OR=1.3, 95% CI:1.06, 1.6). These findings add to evidence of a familial predisposition to bladder cancer. Clarification of the aggregation of bladder cancer in families and with other cancer sites will be of interest as many loci and common polymorphisms related to bladder cancer have yet to be identified in large genomic studies. This article is protected by copyright. All rights reserved.
International journal of cancer. 2021 Jan 27 [Epub ahead of print]
Stella Koutros, Kathy L Decker, Dalsu Baris, Larissa A Pardo, Alison Johnson, G M Monawar Hosain, Nathaniel Rothman, Margaret R Karagas, Molly R Schwenn, Debra T Silverman
Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA., University of Southern Maine, Augusta, ME, USA., Formerly of the Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA., Vermont Department of Health, Burlington, VT, USA., Formerly of the Bureau of Public Health Statistics and Informatics, Department of Health and Human Services, Concord, NH, USA., Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA., Formerly of the Maine Department of Health and Human Services, Maine Cancer Registry, Augusta, ME, USA.