The cost-effectiveness of lung cancer screening with low-dose CT — estimated to cost $81,000 for each quality-adjusted life-year gained — is highly variable based on patient characteristics and how screening is implemented, according to a cost analysis of the National Lung Screening Trial.
Screening with low-dose CT was associated with a 20% (95% CI, 6.8-26.7) reduction in lung cancer mortality in the National Lung Screening Trial (NLST). However, the cost-effectiveness of screening has been a matter of debate, particularly as CMS considers whether to cover low-dose CT screening among at-risk Medicare beneficiaries.
“It is extremely important to consider costs because the screening intervention pertains to so many people — about 9 million in the United States meet the NLST entry criteria — and could get very expensive if not implemented properly,” researcher William C. Black, MD, chest radiologist at Dartmouth-Hitchcock Norris Cotton Cancer Center and professor of radiology at Geisel School of Medicine at Dartmouth College, told HemOnc Today. “[These results] will re-enforce CMS’s concern that screening must be done right but hopefully encourage CMS to support screening under the right conditions.”
William C. Black
The current analysis included 53,302 adults aged 55 to 74 years who participated in the NLST. Black and colleagues compared data from participants assigned screening with chest radiography or low-dose CT in the NLST, as well as data associated with a no-screening strategy. Researchers included quality-adjusted data from a subgroup of participants who completed quality-of-life surveys.
Of the participants included in the current analysis, 1,076 assigned low-dose CT screening were diagnosed with lung cancer, and 469 of these patients died from the disease. Of those assigned radiography, 978 were diagnosed with lung cancer, and 552 of these patients died from the disease.
Projections of lifetime quality-adjusted life expectancies — which included life-years saved after the study period — were higher among patients with lung cancer assigned screening with low-dose CT vs. radiography (6.05 vs. 4.89).
Researchers calculated overall costs — which included costs associated with screening, workup, treatment, time and travel — for each screening strategy. CT screening incurred a cost of $3,074 per person, whereas radiographic screening cost $1,911 per person and no screening cost $1,443 per person.
Although CT scans were associated with higher costs for screening ($1,130 vs. $336), workup ($835 vs. $645) and surgery ($736 vs. $470), researchers noted patients who underwent CT screens had lower costs for chemotherapy ($282 vs. $351) and radiation therapy ($88 vs. $110) compared with patients who underwent chest radiography.
Low-dose CT screening thus cost an additional $1,631 (95% CI, 1,557-1,709) compared with no screening but was associated with a 0.03 (95% CI, 0.01-0.04) increase in life-years per person and 0.02 (95% CI, 0.0088-0.03) increase in quality-adjusted life years per person.
Using these data, researchers calculated an incremental cost-effectiveness ratio (ICER) of $52,000 (95% CI, 34,000-106,000) per life-year gained and $81,000 (95% CI, 52,000-186,000) per quality-adjusted life-year gained.
Subgroup analyses indicated the ICER per quality-adjusted life-year gained was lower for women vs. men ($46,000 vs. $147,000), current vs. former smokers ($43,000 vs. $615,000), and adults with a higher risk vs. lower risk for lung cancer ($52,000 for highest quintile of risk vs. $169,000 for lowest quintile of risk).
Participants aged 55 to 59 years at study entry had the highest ICER per quality-adjusted life-year gained ($152,000), followed by those aged 70 to 74 years ($117,000), those aged 65 to 69 years ($54,000), and those aged 60 to 64 years ($48,000).
Researchers noted cost-effectiveness data were contingent upon several implementation factors, such as who gets screened.
“The cost-effectiveness of CT screening is inversely proportional to the risk of developing lung cancer,” Black said. “The NLST smoking eligibility criteria were fairly stringent. If they were to be broadened to ever smokers 50 to 79 years of age, for example, then the population risk would decrease to about one-half of that in NLST, and the ICER would increase from $81,000 per quality-adjusted life-year gained to about $160,000 per quality-adjusted life-year gained.”
How CT screening is interpreted also will have an effect. For instance, if radiologists use the new American College of Radiology LungRADS reporting system, the positivity rate in NLST would decrease by about 50%, Black said.
Further, the mortality rate from surgery was 1% in the centers that participated in the NLST, which is much lower than the average rate across the United States.
It also is essential that adults who may undergo screening are well informed, Black said.
“One of the biggest potential harms of CT screening is the psychological effects of a false-positive screen,” Black said. “However, we did not see this harm in NLST probably because the participants were so well informed at entry and when they had positive findings.”
William C. Black, MD, can be reached at Dartmouth-Hitchcock Medical Center, 1 Medical Center Drive, Lebanon, NH 03756; email: email@example.com.
Disclosure: The researchers report no relevant financial disclosures.