Lung cancer currently has the greatest mortality rate of cancer patients of all sexes in the United States (Torre et al., 2016). Low-dose CT scans are utilized for lung cancer screening in patients who fall within the NLST entry criteria (Sanchez-Salcedo et al., 2015). The original criteria for screening were age over 55 and pack-year over 30, which were recently changed to age 50 and pack-year over 20 in 2021. The study population in this paper utilized the original criteria. A system developed and copyrighted by the American College of Radiology (ACR) referred to as the Lung CT Screening Reporting and Data System (Lung-RADS) has implemented a standardized method of classifying and interpreting lung cancer chest CT screening results. Lung-RADS has a scoring system which is scaled 1 – 4x (Pinsky et al., 2015) The likelihood of malignancy based on nodule appearance, diameter, and presence of growth comprise the components of which score is given (Chung et al., 2017). Lung-RADS 2 scored nodules are benign nodules and patients follow up for another CT in a year. Lung-RADS 3 nodules are probably benign nodules; however, they do have a low-risk of malignancy. It is known that a select few of these relatively benign appearing nodules will turn out to be malignant. Lung-RADS 4 nodules have a >5% chance of malignancy and can be confirmed through pathology. In this project, a retrospective chart review analyzing patient demographics and pulmonary health history will be correlated to lung-RADS risk likelihood of malignancy. Machine learning will also be utilized to study and analyze radiographic factors associated with the sample. The CT scans of patients who previously scored in an intermediate category will be compiled and analyzed to determine potential common demographical, clinical and radiomic factors which will hopefully allow intermediately categorized nodule indicators to be used to detect cancers earlier and to more accurately classify lesions into benign or malignant categories. In all, the goal of this research is to determine common clinical, demographic and radiomic factors of patients who were deemed intermediate risk and then progressed to a higher categorization. The importance of expanding current risk factors for discrimination of benign from malignant will also be analyzed, along with those specific risk-factors within Lung-RADS intermediately categorized nodules. The characteristics and baseline co-morbidities of RADS 2 and 3 lung cancer patients by follow-up CT results, progression to RADS-4 on follow-up CT and lung cancer diagnosis will be compiled and exemplified.

The number of new cases of lung and bronchus cancer was 55.8 per 100,000 men and women per year. The number of deaths was 44.7 per 100,000 men and women per year. These rates are age-adjusted and based on 2010-2014 cases and deaths. Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined. The knowledge that lung cancer can be successfully treated if caught early has driven a decades-long search to find an accurate and reliable screening test. National Cancer Institute's National Lung Screening Trial (NLST) found that annual screening with Low-Dose CT (LDCT) for asymptomatic patients aged 55 to 74, with a smoking history of at least 30 pack-years, and smokers who quit less than 15 years ago, had a 20% reduction in risk of death from lung cancer. Findings of this trial resulted in that LDCT becoming the gold standard of screening for lung cancer. The SEED method is a community-engaged research approach to develop conceptual models and generate patient-centered research questions. This method has been used to engage community stakeholders of Martinsville, Virginia to develop conceptual models of the factors contributing to lung cancer outcomes. In the first manuscript of this dissertation, these models which were produced by 3 different groups of stakeholders have been examined closely to explore the complexity, similarities, and differences. The models were used to produce a research agenda on the topic of factors impacting lung cancer outcomes for future researchers. A literature review was conducted by the study team on the final research agenda. The goal of this literature review was to avoid duplication of research and to focus future research on the identified gaps. The knowledge and attitudes of the health care providers and patients about lung cancer screening and the barriers in the uptake of LDCT were identified as a research gap. The design of the Martinsville lung cancer study described in the second manuscript of this dissertation responds to this identified research gap. These studies and their results shed light on the factors that impact lung cancer outcomes using a community based participatory approach. / Ph. D.