Introduction
Two thirds of newly diagnosed lung cancer patients in the U.S. would not meet the current USPSTF (United States Preventive Services Task Force) screening criteria, suggesting a need for amendment to the high-risk definition. To provide evidence of additional high-risk subpopulations and estimated gains and losses, we conducted a two-step study using three cohorts.
Methods
Two prospective cohorts are comprised of 5988 primary lung cancer patients diagnosed between 1997-2011 (Hospital) and 850 defined-community residents (Community); the retrospective cohort is the Olmsted County population (Minnesota, USA) followed for 28 years (1984-2011). Subgroups of lung cancer patients who might have been identified using additional determinates were estimated and compared between Community and Hospital cohorts. Findings were supported by indirect comparative projections of two ratios: benefit to harm and cost to effectiveness.
Results
Former cigarette smokers with 30 or more pack-years and 15-30 quit-years age 55-80 formed the largest subgroup not meeting the current screening criteria, constituting 12% of the hospital cohort and 17% of community cohort. Using the expanded criteria suggested by our study may add 19% more CT examinations for detecting 16% more cases when comparing to the USPSTF criteria. Meanwhile, the increases of false positive, over-diagnosed and radiation-related lung cancer death are 0.6%, 0.1%, and 4.0%, respectively.
Conclusions
Current USPSTF screening criteria exclude many patients at high risk for lung cancer. Individuals who are under 81 years, had 30 or more pack-year smoking history, and had quit for 15-30 years may significantly increase the number of non-over diagnosis screen-detected lung cancers, does not significantly add false positive cases, saves more lives, yet with an acceptable amount of elevated scan exposure and cost.