Annual low-dose CT screening of patients at high risk for lung cancer is likely to significantly increase detection of early cancers, but that screening will come at a price, investigators say.

A model that simulates screening of Medicare patients based on recent recommendations from the U.S. Preventive Services Task Force (USPSTF) predicts that an additional 54,000 or so cases of lung cancer would be detected over 5 years, and that most of the cases would be early-stage disease and presumably more easily treated, said Joshua A. Roth, Ph.D., a postdoctoral research fellow at the Fred Hutchinson Cancer Research Center, Seattle.

The model also calculates, however, that the total 5-year Medicare expenditure for a low-dose CT, a diagnostic workup, and cancer care would be $9.3 billion.

Depending on how heavily screening is used, total estimated 5-year costs could range from a low of $5.9 billion (adding $1.90 to monthly premiums) to a high of $12.7 billion ($4.10 extra per month).

"We projected over a 5-year time horizon [that] implementing low-dose CT lung cancer screening in Medicare would result in more lung cancers detected, a shift toward earlier stage at diagnosis, and increased expenditure, particularly on CT scans themselves," Dr. Roth said at a media briefing highlighting research to be presented at the annual meeting of the American Society of Clinical Oncology in Chicago, from May 30 through June 3.

"If screening is covered, it's important for Medicare and health care systems to plan for increased demand for CT imaging and early-stage treatments, for example, thoracic surgery and radiation therapy. Additionally, Medicare should plan for increased expenditure in the budgeting process, as these expenditure increases will need to be funded by either increased premiums or by offsetting other costs," he added.

In December 2013, the USPSTF published a statement recommending annual low-dose CT lung cancer screening for patients from the ages of 55 to 80 years with 30 or more pack-years of smoking history who currently smoke or have quit within the past 15 years. Medicare is scheduled to post a draft decision in November 2014 on whether it will cover the cost of screening under the provision of the Affordable Care Act. Dr. Roth noted that at a recent Medicare coverage advisory meeting, the panelists voted against recommending coverage for screening due to uncertainties about benefits outside of clinical trials.

The authors created their model to mirror the Medicare enrollment and age distribution for 2013. They plugged in lung cancer detection rates and stage at diagnosis using data from the National Lung Cancer Screening Trial, and data on costs of low-dose CT screening and follow-up, confirmatory bronchoscopy and biopsy, as well as stage-specific costs of lung cancer therapy, including the costs associated with end-stage disease.

They looked at three possible scenarios: expected use (based on mammography screening experience), in which about half of all patients offered screening every year actually receive it; low use (25% per year); and high use (75% per year).

They found that if screening is used as expected, it would result in 11.2 million more scans and 54,000 incident cases of lung cancer (most stage 1) over 5 years, compared with no screening. The estimated costs would total $9.3 billion, composed of $5.6 billion more in imaging expenditures, $1.1 billion in diagnostic workups, and $2.6 billion in additional cancer care expenditures.

This increase would translate into a bump in monthly Medicare premiums of $3 per enrollee. By way of comparison, Dr. Roth pointed to a 2012 study in which the authors performed an actuarial analysis showing that offering lung cancer screening as an insurance benefit for the general population would cost about $1 per member per month in 2012 dollars, and that the cost per life-year saved would be below $19,000, which compares favorably with the cost of screening for colorectal, cervical, and breast cancers. He noted, however, that the findings of that study applied to all insured patients, and may not be applicable to the Medicare-only population.

The authors estimated that screening under the expected-use scenario would double the proportion of early-stage cancers detected from the current 15% to 32%, and reduce the proportion of cancers detected in more advanced stages from the current 57% to 40%.

The investigators plan to look at the availability of imaging equipment and trained personnel to estimate how they might be affected by immediate or gradual implementation of the screening recommendations.

Dr. Peter Yu, president-elect of ASCO and a medical oncologist at Palo Alto Medical Foundation in Sunnyvale, Calif., noted that ASCO guidelines support the USPSTF recommendations.

He cautioned, however, that the study provides a forecast of cost but does not reflect real-world expenditures.

"This is a model; this is not actual data," he cautioned.

The study was supported by Genentech. Dr. Roth and Dr. Yu reported having no financial disclosures.

Low-dose CT could up early lung cancer detection - at a price