Familial Risk of Lung Cancer among Nonsmokers and Their Relatives

TLDR

The study evaluated whether family history of lung cancer predicts risk among nonsmokers and their relatives in a population‑based Detroit cohort. Telephone interviews gathered risk factor data from 257 nonsmoking lung‑cancer cases (age 40–84, diagnosed 1984–87), their 2,252 relatives, 277 nonsmoking controls, and their 2,408 relatives. First‑degree relatives of nonsmoking cases aged 40–59 had a 7.2‑fold higher risk (RR = 6.1 after adjustment), offspring of nonsmoking cases also had elevated risk (RR = 7.2), but no excess risk was observed in older nonsmokers or their relatives, indicating that familial susceptibility may be confined to early‑onset cases. Am J Epidemiol 1996; 144: 554–62.

Abstract

The role of family history of lung cancer in predicting lung cancer risk among nonsmokers and their relatives was evaluated in a population-based family study conducted in metropolitan Detroit. Lung cancer risk factor data were collected through telephone interviews with 257 nonsmoking lung cancer cases 40–84 years of age diagnosed between 1984 and 1987, their 2, 252 relatives, 277 nonsmoking controls, and their 2, 408 relatives. Lung cancer in a first-degree relative was associated with a 7.2-fold (95% confidence interval 1.3–39.7) increased risk of lung cancer among nonsmokers in the 40- to 59-year-old age group. This significant increased risk remained after adjustment for the smoking, occupational, and medical history of each family member (relative risk = 6.1, 95% confidence interval 1.1–33.4). Offspring of nonsmoking cases comprised another lung cancer high risk group (relative risk = 7.2, 95% confidence interval 0.5–103). A positive family history did not increase lung cancer risk among nonsmokers 60–84 years of age or their relatives. These findings suggest that susceptibility to lung cancer in families of nonsmoking cases may be evident only in a subset of relatives of early-onset nonsmoking cases. Am J Epidemiol 1996; 144: 554–62.