LDCT for Lung Cancer: More Lung Cancers Earlier, But at What Cost?

June 18, 2014
Leah Lawrence

The controversy of covering low-dose CT for lung cancer screening continues, as groups argue lives saved versus dollars spent.

Editor's Note: An earlier version of this article stated that in April, Medicare voted against coverage of LDCT screening for lung cancer. This has been corrected to read that the Medicare Evidence Development and Coverage Advisory Committee voted against recommending Medicare coverage of LDCT screening for lung cancer. CMS is scheduled to submit a proposed decision by November 2014.

 

The implementation of a low-dose computed tomography (LDCT) lung cancer screening program in Medicare would result in an increased lung cancer detection rate, with a shift toward diagnosis at earlier stage, according to the results of a forecast model. However, the program would also cost an estimated $1.9 billion per year.

Results of this analysis (Abstract 6501) were presented by Joshua Roth, PhD, MHA, a fellow at Fred Hutchinson Cancer Research Center, at the 2014 American Society for Clinical Oncology Annual Meeting in Chicago.

“I think our findings can help to inform ongoing debates about coverage [of LDCT lung screening] in the Medicare program,” Roth said.

Lung cancer is the leading cause of cancer death in the United States, and it is often detected at a distant or advanced stage.

“Screening has great potential to improve lung cancer outcomes, as periodically high-risk patients for lung cancer can catch cancers before they spread, thereby conferring more favorable prognosis,” Roth said.

In 2011, researchers from the National Lung Screening Trial (NLST) reported that its LDCT screening arm had significant reductions in lung cancer mortality compared with X-ray screening. Based on these results, in 2013, the U.S. Preventive Services Task Force (USPSTF) initiated a systematic review of lung cancer screening, and later released a “B” rated recommendation in favor of LDCT screening in healthy people aged 55-80, those with 30 or more pack years of smoking history, who currently smoke, or have smoked within the past 15 years. 

However, in April, the Medicare Evidence Development and Coverage Advisory Committee voted against recommending Medicare coverage of LDCT screening for lung cancer due to the uncertainty of the effects of screening outside of clinical trials. CMS is expected to release a proposed decision by November 2014.

In this study, Roth and colleagues sought to project the five-year clinical, resource and budget impacts of implementing LDCT lung cancer screening in Medicare. They used a forecasting model to project outcomes of a screening strategy compared with a no screening strategy during a five-year time horizon. Outcomes analyzed included lung cancer cases diagnosed by stage, screening scans provided and direct medical expenditure.

During his presentation, Roth demonstrated an example of the decision model structure used in the study.

“First, if patients are classified as high risk for lung cancer, they receive screening and if the result is positive, the result can either be a true positive or a false positive,” Roth explained. “In the case of a true positive, it leads to confirmatory diagnostic testing and then to diagnosis of cancer at a specific stage and they are assigned a cancer care cost and survival. False positives also receive a diagnostic work-up but then are determined to not have lung cancer and patients then flow into the next annual screening interval as a high-risk patient.”

Overall, the results of the study projected that a LDCT screening program would result in about 55,000 more lung cancer diagnoses, most occurring at stage I. There would be an estimated 11 million more LDCT scans, including two million false-positives. Roth pointed out that this equates to about 6,000 scans per day.

Cost estimates projected about $9.3 billion more in direct medical expenditure, equating to $3 per member per month.

“The majority of this increased expenditure is for screening services themselves,” Roth said.

The presentation also included a discussion of study limitations, including the fact that the study assumes that the results of the NLST trial are generalizable to the Medicare population. In addition, the researchers assumed that the only additional patients to undergo LDCT screening would be those noted as high-risk according to the criteria released by USPSTF.

“In reality, it is possible that lower-risk patients would make their way into screening,” Roth said.

He also pointed out that this study was not intended to assess the value of screening, but just the projected costs.

Based on these results, Roth and colleagues suggested that if an LDCT lung cancer screening program was implemented, Medicare and healthcare systems should plan for an increased demand for LDCT imaging and associated health professionals, the treatment capacity for a growing early-stage lung cancer population, and an increased expenditure, particularly for screening exams.