Impact of Expanding Lung Cancer Screening Guidelines on the Early Detection of Lung Cancer in Women and Minorities

Abstract

Lung cancer in women and minorities often occur at a younger age and with minimal (or absence of) tobacco use. As a result, a large proportion of these patients do not qualify for lung cancer screening in the United States despite the fact that it has been proven to reduce cancer-related mortality by 20-24%. However, in July 2020, the USPSTF proposed to loosen screening criteria to include patients who are $50 years old and have a $20 pack year history of smoking. Using CISNET modeling of subgroup data from the NLST and NELSON trials, this will potentially increase the screening eligibility from 14.1% to 20.6%-23.6%, as well as increase lung cancer deaths averted from 381 per 100,000 to 469-558 per 100,000. We propose to evaluate the potential impact of this change on our population of lung cancer patients, many of whom are women and minorities. METHODS:In this IRB-approved retrospective cohort study, the charts of 664 lung cancer patients seen at Los Angeles County Hospital and Norris Comprehensive Cancer Center from 2005-2015 were reviewed. Data on demographic information (ie, age, gender, ethnicity), smoking status, and family history of cancer were collected. A two-sample z-test for proportions was used to test for a difference in the proportion of patients eligible for lung cancer screening using the original vs. new USPSTF guidelines in the overall sample. Data was then stratified by sex and ethnicity, and a two-sample z-test for proportions was used to test for a difference in the proportion of patients eligible for screening using original vs. new guidelines for gender and ethnicity, respectively. A p-value <0.05 was considered statistically significant. All analyses were done in R version 4.0.2. RESULTS:Based on original USPSTF guidelines (age $55, $30 pack-years), only 201 patients (30.3%) would have qualified for lung cancer screening. 421 (63.5%) failed to meet eligibility criteria due to insufficient smoking history alone. However, by lowering the age requirement and smoking threshold based on the new USPSTF changes, an additional 13.2% (p=<0.001) of our patients would have qualified for screening. When stratifying by gender, we found that the revised guidelines would increase screening eligibility among men by 16.5% (p=<0.001) and women by 10.2% (p=<0.001). When stratifying by ethnicity, the revised guidelines would increase screening eligibility among Blacks by 30.2% (p=<0.001), Whites by 13.3% (p¼0.010), Hispanics by 12.5% (p¼0.012), and Asians by 8.5% (p¼0.048). CONCLUSIONS:Original USPSTF lung cancer screening criteria benefit only a narrow subset of lung cancer patients. Our study demonstrates that expanding criteria can potentially improve lung cancer survival in vulnerable subgroups, such as African-Americans and other minorities, who may otherwise not be eligible for screening.CLINICAL IMPLICATIONS: Our study shows that lowering age and smoking requirements allowed for a statistically significant increase in the number of patients screened for lung cancer across both genders, and it was espe...