Researchers at University of Texas Southwestern Medical Center
at Dallas reported that alterations in the genes of a section
of chromosome 3p may reveal the earliest stages of lung cancer.
"Based on these findings, we may eventually be able to develop
a test that would predict who will develop lung cancer,"
said Dr. Adi Gazdar, Professor of Pathology at UT Western. The
study was published in a recent issue of The Journal of the
American Medical Association.
Gazdar and his colleagues examined 24 human lung cancer specimens
in the study. In the earliest stages of lung cancer, the UT Southwestern
researchers determined that genetic alterations or deletions had
developed in a region of chromosome 3p.
Another conclusion was reinforcement of the link between smoking
and the development of such cancer. The study located gene alterations
throughout the lung. "Our findings provide considerable support
for the 'field cancerization' theory," Gazdar said. "That
theory suggests the entire upper respiratory tract is compromised
when exposed to carcinogens like those found in cigarette smoke.
This raises the possibility that cancer may develop in multiple
sections of the lung."
Finding defective genes may facilitate detection of early lung
cancer, when treatment is most effective. In addition, if defective
genes are found, but no malignant lesions can be identified, it
may allow physicians to better counsel the patient about his or
her risk of developing lung cancer.
Gazdar's collaborators in the study included Dr. John Minna, director
of the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern,
and other investigators at UT Southwestern.