New technique detects specific chromosomal damage, may indicate lung c...(strategies that might reduce the persist...),Health

The researchers found a marked difference between the chromosomal abnormality index (CAI) of never-smokers and that of high-risk smokers and patients with lung cancer.

Theres a tremendous amount of chromosomal damage in smokers who dont yet have cancer, said Dr. Franklin. Chromosomal abnormalities were observed in 82 percent of high-risk smokers and in all patients with carcinoma, regardless of their self-reported tobacco exposure. Patients with cancer and high-risk smokers had nearly 23 and 15 times more chromosomal abnormalities, respectively, than never-smokers.

The most common changes among patients with cancer and high-risk smokers were gains on chromosomes 5, 7, 8 and 18.

The results from SKY were confirmed by fluorescence in situ hybridization (FISH). The FISH technique offers a less comprehensive view of genetic changes, but unlike SKY, can detect genetic changes in interphase cells, which are readily available in sputum samples.

Whereas SKY is not a practical tool to directly apply to sputum, it does identify candidate chromosomal sequences that could improve the sensitivity of a FISH probe set for sputum screening and risk assessment, wrote Dr. Franklin. Improvement in sensitivity and perhaps automated processing and analysis could move a FISH-based assay toward clinical application.

The researchers noted that their pilot study could not affirmatively determine whether the changes were predictive of eventual cancer, but their data point to an important avenue for future research. It will be necessary to study larger cohorts for a longer interval, they wrote, concluding, SKY FISH is a feasible technique for comprehensive evaluation of the chromosomal changes in nonmalignant bronchial epithelial cells of high-risk individuals.

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