As efforts are made worldwide to improve the early diagnosis of deadly cancers in order to improve mortality, it is essential to identify discrepancies between populations who undergo screening compared with those diagnosed with cancer. This effort provides screening programs with the opportunity to focus on outreach to underrepresented populations. In the present study, we evaluated the reach of lung cancer screening compared with lung cancer diagnoses at Montefiore Medical Center, an urban institution that provides medical care to the majority of patients in the Bronx, NY. Our study demonstrated that lung cancer diagnosis and screening rates were both highest in the Southeast Bronx. There were no differences in sex between the cohorts, which is particularly significant, as women have traditionally been underrepresented in cancer screens, and concerted efforts must be made to bridge the gap [22]. Overall, we found statistically significant but probably not clinically meaningful differences in neighborhood distribution between the lung cancer diagnosis and screening cohorts, age (64.7 ±6.48 years versus 66.4 ±5.79 years), and SES (-3.11 versus -3.44). The results for SES were especially important to consider, as low SES has been shown to negatively impact patient care in breast cancer, making patients less likely to adequately communicate with their clinical teams and to follow up on guideline-related treatments [23]. It is vital to identify deficits in cancer screening in low SES populations, as there exist strategies to attenuate certain treatment-related risks in these patients by providing health care literacy resources such as pictorial health information [23].
Though both lung cancer and screening cohorts demonstrated the ethnic diversity characteristic of the Bronx, there were statistical discrepancies in the breakdown of ethnicity between the diagnosis and screening cohorts, of uncertain clinical significance. As the Bronx has a high predominance of Hispanic patients, it concurs that Hispanic patients would be in the majority for both the diagnosis and screening groups. Although Hispanic populations in the United States demonstrate lower overall incidences of all cancers, they are more prone to health care disparities related to sociodemographic and cultural factors, with one third of the demographic lacking health insurance in 2013 [24]. Recent institution-based studies have identified Hispanic ethnicity as risk factors for multiple morbidities, including high-mortality STEMIs, incidence of acute critical illness, and metabolic syndrome [11, 25, 26]. As such, the predominance of Hispanics in both lung cancer and screening groups suggests that our hospital system is reaching this traditionally underserved population.
Although there was a significant difference in the breakdown of neighborhood between the cancer diagnosis and screening cohorts, both cohorts demonstrated the highest number of patients from the Southeast Bronx. The highest rates of lung cancer screening were in the Southeast Bronx and Bronx Park and Fordham, the neighborhoods where Montefiore Medical Center has it two major campuses. Our analysis identified the Northeast Bronx, the neighborhood demonstrating the second highest caseload of lung cancer in the borough, as a geographic area towards which more concerted screening efforts should be made. As recognizing a geographic area in high need of screening has allowed institutions the opportunity to distribute patient-facing resources and clinician-led education as well as bolster efforts to facilitate primary care referrals [27]. If the number of clinics proves to be a limiting factor, efforts towards establishing mobile clinics should be considered, as mobile low-dose whole body CT screening has recently emerged as a screening mechanism with a comparable detection rate to that described in the National Lung Screening Trial [28].
The Bronx neighborhoods themselves were heterogeneous in terms of distribution of ethnicity and SES. Interestingly, the data demonstrated a variation in SES based on neighborhood. For example, the in Kingsbridge and Riverdale, which demonstrated the highest average SES, the standard deviation was 3.652, whereas in the Northeast Bronx, the standard deviation in SES was 1.906. Future avenues of study to investigate whether living in a neighborhood with a relatively high average SES confers health benefits or even risks despite falling into a low SES bracket. Previous literature has identified a smaller incidence of non-small cell lung cancer in geographic areas with high average income [29]. Moreover, lung cancer incidence is positively associated with exposure to tobacco, including exposure from secondhand smoke [30]. As individuals within higher SES brackets tend to be less likely to smoke [31], residence within neighborhoods with higher average SES where tobacco exposure is more likely to be minimal may confer a protective effect in terms of carcinogenic exposure.
Demographics-based personalization of lung cancer screening programs should be considered in all global efforts to achieve higher screening rates in eligible populations. Future study expanding on the role of sex in screening should consider the role of gender identity in lung cancer screening, as non-gender conforming individuals have been demonstrated as having significantly lower rates of disease detection, especially when individuals are situated in underserved areas [32]. These studies will take place in a continued effort to address psychosocial barriers to health and maintain equal access to care among all.
Limitations
Patients were not stratified by smoking behavior when SES was evaluated in discrete neighborhoods within the cancer diagnosis cohort; smoking has previously been identified as a confounding variable in the relationship between SES and lung cancer. That said, recent evidence has limited the significance of this confounding relationship, suggesting that controlling for smoking history attenuates but does not eliminate the significant indirect relationship between SES and lung cancer incidence [5]. There were additional limitations in the method by which the EMR calculated SES, which did not include variables such as the total number of domestic occupants supported per household. Some selection bias may also have been introduced, as the study cohorts consisted of patients who willingly reported to the hospital. Furthermore, demographics were not stratified by age, which was shown to affect the risk profile of ethnicity and medical comorbidities for STEMI patients at Montefiore [11].