NCA - Screening for Lung Cancer with Low Dose Computed Tomography (LDCT) (CAG-00439R) - Decision Memo

(NCI, 2021)Among the randomized controlled trials in our evidence base, one study, the NLST, had data on African-Americans, who comprised 4.4% of the study population (NLST, 2019). Women comprised 16.4% (NELSON; de Koning, 2020) to 44.8% (DLCST; Wille, 2016) of the study populations.Regarding the issues underlying health disparities in lung cancer screening, Krist and colleagues (2021), on behalf of the USPSTF, reported that African American/Black (Black) men have a higher incidence of lung cancer than White men, and Black women have a lower incidence than White women. These differences are likely related to differences in smoking exposure (i.e., prevalence of smoking) and related exposure to carcinogens in cigarettes. The differences may also be related to other social risk factors (USPSTF, Krist; 2021).Additionally, in the American College of Chest Physicians (CHEST) guidelines for low dose CT lung cancer screening, the authors reported that [a]mong patients enrolled in the NLST, individuals who currently smoke and black subjects experienced the highest lung cancer mortality and the greatest benefit from LDCT screening. However, minorities and those with low SES [socioeconomic status] (who are more likely to be currently smoking) often experience disparities in receiving appropriate preventive health care. LDCT screening has been slow to be implemented and is underused nationally despite coverage by private and public insurers. Lower rates of screening uptake have been found among minorities, those with a lower educational status, and individuals with low SES. As screening is implemented more widely, outreach to underserved populations to ensure that eligible individuals receive LDCT screening will be of critical importance to prevent disparities. Little work has been done to establish the most effective strategies (Mazzone, Executive Summary; 2021).More specifically on smoking and race and gender disparities, the authors of the American Thoracic Society (ATS) statement reported that incidence and mortality rates vary by race, ethnicity, and sex. African American and Native Hawaiian individuals have the highest incidence, and white individuals have midlevel incidence, whereas Hispanic and Asian individuals have the lowest rates. These differences in incidence are more evident by sex at low levels of smoking exposure and at younger ages. Although the national decline in the incidence of lung cancer among men has been greater than that among women, in the 40- to 44-year-old age group, the female-to-male incidence rate ratio of lung cancer increased from 0.82 in the 19951999 period to 1.13 in the 20102014 period. The crossover in rates to higher incidence rates in younger women occurred in birth cohorts born after 1965 and was limited to white and Hispanic individuals; among white individuals, the rate rose from 0.88 in the 19951999 period to 1.17 in the 20102014 period, and among Hispanic women, who smoke less than young Hispanic men, the rate rose, more notably, from 0.79 to 1.22. African American men have the highest lung cancer mortality of all groups, and lung cancer is the leading cause of mortality in Hispanic men and the second leading cause of cancer mortality in Hispanic women. Socioeconomic and racial disparities account for approximately 37% of premature cancer deaths in the United States and are a major public health concern. The largest socioeconomic disparity is reported for lung cancer with mortality rates five times higher in the least educated men than in the most educated men. Secondary analyses of the NLST data show that African American individuals are more likely to benefit from LCS [lung cancer screening] in terms of mortality reduction (hazard ratio, 0.61 in African American individuals vs. 0.86 in white individuals). In addition, the reduction in lung cancer mortality after LCS is suggestive of being more favorable in women than in men (Rivera, 2020).For health disparities by gender in lung cancer screening, as noted earlier in the NCA, Becker et al. (2020) reported an intriguing observation in LUSI [in that there] is the apparent heterogeneity (although only borderline significant, P value for heterogeneity= 0.09) in the effect of LDCT screening on lung cancer mortality by sex, suggesting a mortality reduction among the women only, (Becker, 2020) and the authors go on to report that the findings from LUSI are in line with those from other trials, including NLST [National Lung Screening Trial], that suggest a stronger reduction of lung cancer mortality after LDCT screening among women as compared to men (Becker, 2020). Additionally, the LUSI study authors report that this gender heterogeneity could be the result of different relative counts of lung tumor [histologic] subtypes occurring in men and women, but that the numbers of cancer deaths in LUSI were too small to examine whether the apparent heterogeneity in relative mortality hazards for men and women could be explained by differences in tumor histology, or whether it could have been entirely due to chance (Becker, 2020).Regarding the impact of health disparities on eligibility for lung cancer screening, the authors of the American Thoracic Society (ATS) statement reported that [r]acial and ethnic differences in lung cancer risk that are not accounted for in current eligibility criteria for LCS are striking. African American individuals exhibit higher smoking-adjusted risk of cancer, despite smoking less than white individuals. Recent data from a large cohort study demonstrated that lung cancer cases in African American individuals were less likely to be eligible under USPSTF screening guidelines than lung cancer cases in white individuals (17% vs. 31%, respectively), primarily because of fewer pack-years smoked (Rivera, 2020). Further, [s]creening eligibility also does not account for sex-based differences in lung cancer risk. Lung cancer tends to be diagnosed in women at younger ages than in men, and women start smoking at a later age and smoke less intensively than men. A recent study reported that although smoking prevalence was lower in women born after 1965, the incidence rate of lung cancer was significantly higher than in men, especially in white and Hispanic women, suggesting that sex differences in smoking behavior do not fully explain increased lung cancer rates in young women (Rivera, 2020).Strategies to Address Health DisparitiesTo address health disparities in lung cancer screening, the authors of the American Thoracic Society (ATS) statement on healthcare disparities reported that [d]isparities in lung cancer incidence, diagnosis, treatment, and mortality are well documented. There is concern that disparities in the implementation of and access to lung cancer screening (LCS) will further widen existing gaps in lung cancer care and mortality among racial and ethnic minorities, individuals of low socioeconomic status (SES), and uninsured or underinsured populations (Rivera, 2020). One of the key conclusions of the ATS statement was that in the United States, lung cancer incidence and mortality rates vary by race, ethnicity, sex, and SES [socioeconomic status]. LCS saves lives, and the mortality reduction benefit has been shown to be more favorable in African American individuals than in white individuals and is suggestive of being more favorable in women than in men (Rivera, 2020).Additionally, the authors of the American Thoracic Society (ATS) statement on healthcare disparities suggest several strategies to address health disparities in lung cancer screening. Healthcare providers and organizations should provide access to evidence-based tobacco treatment that includes behavioral counseling and should develop programs that address differences in cultural beliefs, language, and literacy; healthcare institutions should provide training for providers on communication techniques in LCS [lung cancer screening] SDM [shared decision-making] to build and improve patient trust[; and] research scientists and healthcare providers should develop and test SDM tools that are culturally sensitive and understandable by those with lower literacy and numeracy and by those of differing cultural backgrounds (Rivera, 2020). The American Thoracic Society statement concludes that [s]ocially and economically disadvantaged populations are among the most vulnerable populations at risk for poor lung cancer outcomes. Significant disparities across the continuum of LCS implementationnot getting screened for tobacco use, not meeting eligibility criteria, not having access to quality screening and tobacco treatment, and lack of insurance, among manythreaten to worsen disparities in lung cancer. Dedicated efforts are needed to address existing multilevel barriers to LCS that widen disparities and to respond and develop actionable plans to implement strategies using multipronged approaches deployed simultaneously to decrease disparities. Thoughtful implementation of strategies that address racial, ethnic, socioeconomic, and sex-based differences in smoking behaviors and lung cancer risk; address inequitable distribution of LCS resources and access to health insurance coverage for LCS; and provide education and resources will be necessary to achieve equitable outcomes in LCS (Rivera, 2020).CMS encourages shared decision-making between patients and practitioners that is culturally sensitive and understandable by those with lower literacy and numeracy and by those of differing cultural backgrounds; and if appropriate, participation in a lung cancer screening program. CMS also encourages the use of tobacco cessation and abstinence programs that address differences in cultural beliefs, language, and literacy.Modification of Eligibility Criteria for Age and Smoking HistoryTwo studies evaluated the impact of the revised USPSTF eligibility criteria for age and smoking history on health disparities in lung cancer screening. In an ongoing prospective observational cohort study of community health centers across 12 southern US states, there were a total of 48,364 Southern Community Cohort Study participants who were ever smokers, of which 5,654 of 32,463 African American smokers (17%) were eligible for USPSTF screening compared with 4,992 of 15,901 white smokers (31%) (P < .001) (Aldrich, 2019). The study authors found that [l]owering the smoking pack-year eligibility criteria to a minimum 20-pack-year history was associated with an increased percentage of screening eligibility of African American smokers from 17.4% to 28.5% (Aldrich, 2019). This finding was likely due to African American smokers [tending] to smoke fewer cigarettes per day compared with white smokers and [having] a lower overall smoking pack-year history (Aldrich, 2019). Additionally, [r]educing the minimum age criterion for screening to 50 years for African American smokers in addition to lowering the smoking pack-year requirement would further increase the eligibility of African American persons diagnosed with lung cancer to 57.8% (457 of 791) (Aldrich, 2019). The authors concluded that [c]urrent USPSTF lung cancer screening guidelines may be too conservative for African American smokers. The findings suggest that race-specific adjustment of pack-year criteria in lung cancer screening guidelines would result in more equitable screening for African American smokers at high risk for lung cancer (Aldrich, 2019).Reese et al. (2021) conducted a study to determine [w]hat change will be associated with the revised US Preventive Services Task Force (USPSTF) lung cancer screening guideline for screening eligibility among female, Black, and Hispanic populations (Reese, 2021). In the revised criteria, age was modified to 50 to 80 years [from 55 to 80 years]; smoking history, to 20 pack-years (Reese, 2021). The authors found that [i]n this cross-sectional study of the [Centers for Disease Control and Preventions] Behavioral Risk Factor Surveillance System for 2017 and 2018 [across 19 states], the proportion eligible for screening among current and former smokers increased by 30.3% for men, 40.5% for women, and 31.9% for White, 76.7% for Black, and 78.1% for Hispanic populations. Compared with men, women had lower odds of eligibility, and compared with White [individuals], Black and Hispanic individuals had lower odds of eligibility (Reese, 2021). The authors concluded that [t]he revised USPSTF guideline may likely increase lung cancer screening rates for female, Black, and Hispanic populations. However, despite these potential improvements, lung cancer screening inequities may persist without tailored eligibility criteria (Reese, 2021).Several societies and the USPSTF have developed statements on the impact of changing the lung cancer screening eligibility criteria for age and smoking history. In the American College of Chest  Physicians CHEST) guidelines for low dose CT lung cancer screening, the authors reported that [l]imited data comparing lung cancer mortality outcomes by race, smoking status, malignancy risk, and the presence of COPD were available. The NLST was the only trial for which there is data reporting lung cancer mortality stratified by race. Black individuals had a non-statistically significant larger benefit [from lung cancer screening] than white individuals (HR 0.61 vs. 0.86, p = 0.29) (Mazzone, Panel Report 2021). Additionally, [c]urrent age and smoking history-based eligibility criteria engender disparities with respect to race/ethnicity, sex, smoking intensity, years since quitting, and for special populations such as people living with HIV; see [citation in Mazzone] for a comprehensive review. By reducing the age and the pack-years eligibility for screening from 55 to 50 and 30 to 20, respectively, as in the USPSTF draft recommendations, more African Americans will be eligible for screening which may partially eliminate this particular disparity (Mazzone, Executive Summary; 2021).