Chest X-Rays Often Wrong About Lung Cancer
The majority of abnormal findings prove to be false positives, study finds
WEDNESDAY, Dec. 21, 2005 (HealthDay News) -- While chest X-rays can detect early lung cancer, they can also produce many false positive results, a new study finds.
Researchers at the U.S. National Cancer Institute analyzed data from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Of the more than 67,000 people who received a baseline chest X-ray when they entered the trial, nearly 6,000 -- close to 9 percent -- had abnormal results that required follow-up.
After further tests, just 126 (2.1 percent) of those with abnormal chest X-rays were diagnosed with lung cancer within 12 months of their initial chest X-ray. Of the lung cancers that were detected, 44 percent were stage I. Patients with stage I lung cancer are considered good candidates for surgery.
"The positive predictive value (of chest X-rays) was low. That means that there were a lot of false positives on the initial X-rays. If you get a positive result from a chest X-ray, the message is 'don't panic,'" Dr. Christine Berg, the NCI investigator leading the trial, said in a prepared statement.
She noted that tissue variations and other benign factors can appear as tumors on X-rays.
"The rate of early cancer detection was better than what we see in the general community. But it remains to be seen if that translates into a mortality benefit. It is too early to make any recommendations regarding chest X-rays as a lung cancer screening tool in the general population," Berg said.
The findings are reported in the Dec. 21 issue of the Journal of the National Cancer Institute.
The American Cancer Society has more about early detection of lung cancer.