A case-control analysis of lymphocytic chromosome 9 aberrations in lung cancer

Cytogenetic aberrations on chromosome 9 have been reported to be one of the most frequent genetic changes in lung tumorigenesis. Although many of these changes have been detected in lung carcinoma specimens, there is growing evidence showing the concordance between chromosomal alterations in primary lung tumors and peripheral blood lymphocytes (PBLs). We investigated whether spontaneous aberrations on chromosome 9 in PBLs are associated with the presence of lung cancer and with a family history of cancer. A personal interview, to construct a detailed epidemiologic profile including family history of cancer, was conducted on 174 lung cancer cases and 162 matched controls. One hundred metaphases from PBLs of each subject were analyzed for chromosome 9 aberrations using the whole chromosome painting technique. Overall, the mean proportion of individuals with chromosome 9 abnormalities in their PBLs was significantly higher in cases (96.0%) than in controls (60.5%) (p < 0.05). After adjustment by age, gender, ethnicity, family size, and pack-years, there was a 16.63-fold significantly elevated odds ratio (OR) for lung cancer associated with chromosome 9 aberrations. When subjects were categorized by frequencies of the chromosome 9 lesions, we observed significantly increased odds ratios of 11.13 (4.66, 26.58) and 27.45 (11.15, 67.54) for individuals with 1 chromosome 9 aberration and ≥2 chromosome 9 aberrations, respectively. By performing family history analyses, we further observed that control individuals with chromosome 9 aberrations were more likely to report a family history of any cancer (OR = 1.67 [0.84, 3.32]) and lung cancer (OR = 2.49 [0.81, 7.67]). Our findings suggest that chromosome 9 aberrations in PBLs might be considered a marker of lung cancer predisposition and may be associated with familial aggregation of cancer.