Lung Cancer Screening in a Surgical Lung Cancer Population: Analysis of a Rural, Quaternary, Academic Experience

Regional trends in diagnosis of advanced lung cancer in Michigan over 33 years

Background

Lung cancer is the most common cancer killer worldwide. Nearly 80 percent of lung cancers are diagnosed at advanced stages. Lack of access to medical care and undwerutilized lung cancer screening are key reasons for advanced diagnoses. We sought to understand the regional differences in presentation of lung cancer across Michigan. Utilizing a comprehensive cancer registry over 33 years, our goal was to examine associations between sociodemographic patient factors and diagnoses at advanced stages.

Methods

The Michigan Cancer Registry was queried from 1985 to 2018 to include all new diagnoses of non-small cell lung cancer (NSCLC) using International Classification of Diseases for Oncology (ICD-O) version 3 codes. NSCLC was categorized as early, regional and distant disease. Advanced disease was considered to be any disease that was regional or distant. NSCLC rates were calculated and mapped at the zip code level using the 2010 population as the denominator and spatial empirical Bayes methodology. Regional hospital service areas were constructed using travel time to treatment from the patient's zip code centroid. Logistic regression models were estimated to investigate the significance of rural vs. urban and travel time on level of disease at presentation. Kaplan-Meier and multivariate survival analysis was performed to evaluate the association between distance from the nearest medical center and length of survival controlling for known risk factors for lung cancer.

Results

From 1985 to 2018, there were 141,977 patients in Michigan diagnosed with NSCLC. In 1985, men were 2.2 times more likely than women to be diagnosed but by 2018 women and men developed disease at equal rates. Mean age was 67.8 years. Among all patients with known stage of disease, 72.5% of patients were diagnosed with advanced disease. Regional and distant NSCLC rates were both higher in the northern parts of the state. Longer drive times in rural regions also significantly increased the likelihood of advanced NSCLC diagnoses, in particular regional lung cancer. Patients with longer drive times also experienced overall worse survival after controlling for other factors.

Conclusions

Regional disparities exist in Michigan for diagnoses of NSCLC at advanced stages. Factors such as lack of screening in urban regions and distances to treating institutions in rural areas likely contribute to the increased likelihood of advanced NSCLC. Future interventions should target the specific needs of residents to detect disease at earlier stages and improve overall outcomes.

Access to Lung Cancer Screening

Rural and racial/ethnic minority communities experience higher risk and mortality from lung cancer. Lung cancer screening with low-dose computed tomography reduces mortality. However, disparities persist in the uptake of lung cancer screening, especially in marginalized communities. Barriers to lung cancer screening are multilevel and include patient, provider, and system-level barriers. This discussion highlights the key barriers faced by rural and racial/ethnic minority communities.

Rural-urban survival disparities for patients with surgically treated lung cancer

BACKGROUND

Nonsmall-cell lung cancer (NSCLC) is a common diagnosis among patients living in rural areas and small towns who face unique challenges accessing care. We examined differences in survival for surgically treated rural and small-town patients compared to those from urban and metropolitan areas.

METHODS

The National Cancer Database was used to identify surgically treated NSCLC patients from 2004 to 2016. Patients from rural/small-town counties were compared to urban/metro counties. Differences in patient clinical, sociodemographic, hospital, and travel characteristics were described. Survival differences were examined with Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

The study included 366 373 surgically treated NSCLC patients with 12.4% (n = 45 304) categorized as rural/small-town. Rural/small-town patients traveled farther for treatment and were from areas characterized by lower income and education(all p < 0.001). Survival probabilities for rural/small-town patients were worse at 1 year (85% vs. 87%), 5 years (48% vs. 54%), and 10 years (26% vs. 31%) (p < 0.001). Travel distance >100 miles (hazard ratio [HR] = 1.11, 95% confidence interval [CI]: 1.07-1.16, vs. <25 miles) and living in a rural/small-town county (HR = 1.04, 95% CI: 1.01-1.07) were associated with increased risk for death.

CONCLUSIONS

Rural and small-town patients with surgically treated NSCLC had worse survival outcomes compared to urban and metropolitan patients.