Duke Study Recommends Against Annual LDCT in a Subset of High-Risk Lung Cancer Patients

March 22, 2016
Surabhi Dangi-Garimella, PhD

"Our analysis suggests that annual screens may not be warranted for patients who have had an initial negative scan, and future risk prediction and cost-effectiveness models could incorporate these data to improve screening guidelines," said the study's lead author.

An annual low-dose computed tomography (LDCT) screen may not be necessary in lung cancer patients deemed high-risk but with a negative LDCT screen, a new study in The Lancet Oncology has determined. This could, in addition to reducing unwarranted patient exposure, be a significant healthcare saving.

Following a “B” recommendation for annual lung cancer screenings with LDCT by the US Preventive Services Task Force in 2014 for adults ages 55 to 80 years who had smoked 30 pack years, Medicare announced coverage for an annual screen for eligible enrollees. Researchers at the Duke Cancer Institute evaluated lung cancer incidence in high-risk patients who participated in the National Lung Screening Trial (NLST), to determine whether less frequent screening could be justified in certain subpopulations.

Following a retrospective cohort analysis of data from NLST, which compared 3 annual LDCT assessments with 3 annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals. Eligibility was defined as:

  • aged 55-74 years
  • at least a 30 pack-year history of cigarette smoking,
  • had quit within the past 15 years (if a former smoker).

Participants were followed for 5 years after their last annual screen. The outcomes that were analyzed included frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. Of the initial 26,231 participants, 19,066 were identified as having a negative LDCT scan. Only 2% of these were diagnosed with lung cancer at the time of their last available follow-up, 0.09% were diagnosed with lung cancer in the first year after a negative screen and before their scheduled first annual screen, and 0.4% were diagnosed with lung cancer between the first and second annual screening.

“Our analysis suggests that annual screens may not be warranted for patients who have had an initial negative scan, and future risk prediction and cost-effectiveness models could incorporate these data to improve screening guidelines,” said Edward F. Patz, Jr, MD, the James and Alice Chen Professor of Radiology at Duke and lead author of the study, in a statement.

The authors predict that in the absence of the first annual screen following the first negative test, would have resulted in an additional 28 lung cancer deaths over the course of the study.

“Because overly frequent screening has associated harms, increasing the interval between screens in participants with a negative low-dose CT prevalence screen might be warranted,” they conclude.

Reference

Patz EF, Greco E, Gatsonis C, Pinsky P, Kramer BS, Aberle DR. Lung cancer incidence and mortality in National Lung Screening Trial participants who underwent low-dose CT prevalence screening: a retrospective cohort analysis of a randomised, multicentre, diagnostic screening trial [published online March 18, 2016]. The Lancet Oncology. doi:http://dx.doi.org/10.1016/S1470-2045(15)00621-X.