Researchers Work to Detect Early Signs of Lung Cancer

[Christine]

An ounce of prevention has always been worth a pound of cure, and when it comes to preventing lung cancer, it could be worth lives.

Lung cancer is the number one cause of cancer deaths in the United States As a matter of fact, it is responsible for more deaths than colon, breast and prostate cancers all put together. While smoking is the number one risk factor for someone to develop lung cancer, not all lung cancer patients are smokers and never have been. And quitting smoking will gradually reduce the risk of lung cancer, but much of the damage that has been done by years of smoking is irreversible.

Now if there were a way to test who are at high risk for developing lung cancer and look for any genetic changes that occur before the cancer develops, we may be able to prevent a good number of cases each year.

Researchers at the University of Colorado are doing just that. A team led by Wilbur A. Franklin, M.D.,is Professor of Pathology at the University of Colorado Health Sciences Center has set out to develop the techniques for screening the lungs for lesions that could indicate pre cancerous genetic changes.

Recent discoveries have shown that these genetic changes are not a random occurrence. They are the result of very specific

chromosomal instabilities that may be the beginning signs of future cancer

One of the other researchers working on the study is Marileila Varella-Garcia, M.D., also of UCHSC/ Dr. Varella- Garcia focused on these chromosomal changes.

They had a group of 71 participants, 14 of which had lung cancer, 43 of which were smokers considered to be at high risk for developing lung cancer and 14 of which were healthy and non smokers. They used a method called spectral karyotyping (SKY) to examine the bronchial epithelium in the participants, hoping that they would be able to identify the underlying genetic changes that could be the forerunners of cancer.

The researchers did find that there was a significant difference in the chromosomal abnormality index (CAI) of those who never smoked as compared to the index of the smokers and the lung cancer patients.

Of the smokers who did not have cancer, 82% had chromosomal abnormalities. Patients with cancer had 23 times more of the chromosomal abnormalities than non smokers and smokers who did not have cancer had 15 times more.

In order to confirm the results they got from using the SKY system, they used another technique called fluorescence in situ hybridization (FISH). This one does not have as comprehensive a view of the changes, but it does do something that SKY does not. It can detect changes in interphase cells which are cells that are at the point in their cycle when ir doubles its cytoplasm, the gelatinous, semi-transparent fluid that "fills" most cells, and synthesizes DNA.

This is only the first step in the research. It is too early yet to give a definitive yes on whether or not the changes are a true prediction of future cancer, but the data is positive enough to so that further research is planned.