Family history of cancer, mutagen sensitivity, and increased risk of head and neck cancer

To evaluate individual cancer susceptibility, 170 previously untreated pati ents with pathologically-confirmed squamous cell carcinoma of the oral cavi ty, pharynx, and larynx, and 175 age- and sex-matched health controls were investigated for the occurrence of cancer in first-degree relatives along w ith other established risk factors for head and neck cancer. More than 54% of these subjects were assayed for mutagen sensitivity by quantifying in-vi tro bleomycin-induced chromosomal breaks within peripheral blood lymphocyte s. After adjusting for age, gender, education, family income, tobacco and a lcohol consumption, the odds ratio associated with three or more first-degr ee relatives with cancer at any site was 3.79 (95% CI 0.9-15.9) with a line arly-increased trend in risk (P = 0.040), Significantly elevated risk was f ound to be associated with a history of cancer within siblings (OR = 2.61, 1.2-5.6, P = 0.014). Patients with a family cancer history and mutagen sens itivity were at greatest risk (OR = 7.88, 2.5-25.3, P = 0.005), indicating an additive interactive effect. The findings suggested that genetic familia l influence is important in the causation of head and neck cancer. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.