SHARED CYTOGENETIC ABNORMALITIES IN LUNG-TUMORS AND CORRESPONDING PERIPHERAL-BLOOD LYMPHOCYTES

We analyzed chromosomal alterations in primary lung tumours and peripheral blood lymphocytes (PBLs) from 10 lung cancer patients (nine with non-small cell lung carcinoma and one with small cell lung carcinoma) to determine whether there were shared chromosomal changes in the normal and diseased tissue of these cases. This study revealed that each paired sample had at least three chromosomes and two chromosomal regions in common for structural rearrangements. The chromosomes most frequently found structurally altered in paired analysis were 1 and 3 (60% each), 5 (50%), 6, 7, and 9 (40% each), and 14 (30%). Chromosome region 3p13-3p21 was structurally rearranged in both the normal and tumour tissues of three patients. Chromosome 3 was structurally rearranged in all ten tumours. The chromosome arms most commonly affected in the tumours were 3p (nine times), 9p and 5q (eight times each), Ip and 7q (six times each), 10q and 11q (five times each), 14q and 6q (four times each). The most frequently affected chromosomal regions in these tumours were (in decreasing order) 9p23-p24, 3p21-3p13, 5q11, 1p34, 7q22, and 11q13. Frequent polysomy of 7 and 12 and loss of D-group chromosomes were also observed in the tumours analyzed. Comparing the changes found only in tumours with those found in both PBLs and tumours was helpful in shedding some light on the probable sequence of genetic events leading to lung cancer. This investigation also offered compelling evidence that genomic instability at the chromosomal level in PBLs corresponds with the genetic changes observed in tumours indicating that PBL analysis can help identify the early chromosomal changes in lung cancer. PBL chromosomal analysis thus has a promising future in the genetic analysis of lung cancers.