title: Aggregation of cancer among relatives of never-smoking lung cancer patients.
abstract: The authors evaluated the familial aggregation of lung and other cancers in first-degree relatives of lung cancer patients self-reported to be lifetime never smokers. The data, derived from a large lung cancer case-control study, included 2,465 first-degree relatives of 316 never smoker lung cancer cases and 2,441 first-degree relatives of 318 never smoker controls, frequency matched to the cases on age, gender and ethnicity. The median age of the cases and the controls was 61 years, about 2/3 were women, and about 80% were Caucasian. Overall, there was a 25% excess risk [95% CI (1.05-1.50)] of any type of cancer among the first-degree relatives of cases, and case offspring exhibited a 2-fold excess cancer risk (1.03-4.10) compared with control offspring. There was also a 44% excess risk (1.05-1.97) of young onset cancers (before age 50) among relatives of cases. Smoking case relatives had an increased risk of any cancer [odds ratio (OR) = 1.36 (1.03-1.81)] and a 5.52-fold risk (1.19-25.51) of young onset lung cancer compared with smoking control relatives. Female case relatives had a 58% excess breast cancer risk (1.04-2.43), and case mothers a 2.57-fold breast cancer risk (1.16-4.24). A significant excess of testicular cancer was observed among case male relatives [OR = 12.32 (1.71-88.90)], although based on only 9 cases. The age at lung cancer diagnosis tended to be earlier in case relatives (61.4, SD = 12.9) compared with control relatives (66.2, SD = 11.4; p = 0.07). Our analysis provides further evidence for the importance of genetic factors for lung cancer in never smokers.
authors.affiliation: Department of Epidemiology, The University of Texas, M. D. Anderson Cancer Center, Houston, TX 77030, USA. oygorlov@mdanderson.org
authors.forename: Olga Y
authors.initials: OY
authors.lastname: Gorlova
authors.forename: Shih-Feng
authors.initials: SF
authors.lastname: Weng
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Amos
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Spitz
mesh_terms: D017677:Age Distribution; D000368:Aged; D005190:Family; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000453:epidemiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000473:pathology; D012307:Risk Factors; D012907:Smoking