Chest x-rays find cancers along with false positives

Chest x-rays can detect early lung cancer in asymptomatic people but at the cost of many false positives, according to preliminary findings from the National Cancer Institute's Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. The study is the first major controlled trial to include women in its evaluation of lung cancer screening.

Of the 67,038 men and women who received a baseline chest x-ray, 5991 (8.9%) were positive and required additional evaluation. Of the 5991 positive baseline screens, 126 (2.1%) were found to have cancer within 12 months.

Comparing the results of women and men, researchers found that the incidence of positive screens was lower among women (8.2%) than among men (9.6%). This trend was found in every age group (between 54 and 75 years), in current and former smokers, in those who never smoked, and in smokers with a history of fewer than 30 pack-years (smoking 20 cigarettes per day for 30 years) or of 30 or more pack-years.

The study appeared in the Dec. 21, 2005, issue of Journal of the National Cancer Institute.