IASLC: Moderate Dysplasia Plus Abnormal FISH Increases Lung Cancer Risk

CHICAGO, Nov. 3 -- Abnormal fluorescence in situ hybridization (FISH) probe results significantly increase the risk of invasive lung cancer in smokers with severe or moderate dysplasia on bronchial biopsy, researchers reported here.

An abnormal FISH analysis was associated with five times the risk of developing invasive lung cancer, said Steinn Jonsson, M.D., of the University of Colorado Health Sciences Center in Aurora, Colo., at the International Society for the Study of Lung Cancer symposium on malignancies of the chest and head and neck.

Not surprisingly when bronchoscopy detected carcinoma in situ the risk was even greater -- a 35-fold increase for invasive lung cancer (OR: 35.2, 95% CI: 5.3-223), he said.

But there was no increased risk associated with angiogenic squamous dysplasia, Dr. Jonsson said.

Dr. Jonsson and colleagues analyzed aneursomy, angiogenesis and histology from bronchial biopsies of 106 smokers (83 men) with a mean age of 63 and a mean smoking history of 62.8 pack years. The population included 83 males and 23 females.

They used 4-color FISH probe targeting centromere 6, 5p15.2, EGFR and CMYC. Three or more copies for two or more of these DNA targets indicated presence of an aneusomic cell.

At the time of biopsy, 30 patients had lung cancer-two incident cases and 28 prevalent cases. Fourteen subjects had carcinoma in situ, 42 had severe dysplasia, and 50 had moderate dysplasia.

FISH analysis was abnormal in 12 patients with mild dysplasia and in 15 with severe dysplasia. Abnormal FISH results were also found in two patients with CIS and 18 patients with lung cancer.

Among patients who were free of lung cancer at the time of the biopsy, an abnormal FISH analysis was associated with an OR of 5.04 for invasive lung cancer (95% OR 1.8-14.5.), which suggested the need for close monitoring of these patients, he said.