Investigators examine lung cancer screening efforts
Researchers recently assessed the widespread implementation of CT scanning for the early detection of lung cancer in a public health setting.
For the study, published December 21, 2012, in PLoS ONE, Dr David Gerber, an oncologist and assistant professor of internal medicine at UT Southwestern Medical Center, used electronic medical records data from a single-center study that is further investigating results from the National Lung Screening Trial (NLST) released in 2010. The NLST already revealed a potential reduction in lung cancer mortality with widespread CT-based screening of a population of those patients aged 55 to 74 years with a smoking history of at least 30 years of one-pack-a-day smoking.
Gerber and his team reviewed more than 400 records of patients who were diagnosed with stage I or stage II non–small cell lung cancer over a recent 10-year period. The researchers discovered that during this period, the proportion of cases identified by CT scan (without preceding chest X-ray) increased almost 50%. Concurrently, the proportion of patients who received initial chest imaging to evaluate symptoms decreased by more than 30%. Yet, only half of the early-stage lung cancer cases would meet NLST criteria for lung cancer screening.
“Our results suggest that a substantial proportion of patients currently presenting with early-stage lung cancer would continue to do so independently of radiographic screening if such a program were implemented according to NLST criteria,” Gerber said. “The possibility of frequent detection of early-stage disease outside of a screening context seems more likely with lung cancer than with other malignancies, as chest imaging is a more common practice in non-screening clinical care than are mammograms, Pap smears, and colonoscopies.”
Whether radiographic screening for lung cancer should be extended to a broader population has yet to be determined.
Gerber said, “In our sample, almost 25% of patients with early-stage disease would be ineligible for screening because they are too old under NLST criteria.” However, according to Gerber, certain professional organizations (eg, National Comprehensive Cancer Network) do not have an age cutoff within their screening recommendations.
“Until there is sufficient evidence to offer screening to a broader population,” Gerber said, “clinicians should remain aware of the diverse reasons for and circumstances of early-stage lung cancer presentation to expedite further evaluation and potentially curative treatment.”
Source: UT Southwestern Medical Center.