Midthun, David E.

Abstract Objective The study sought to test the feasibility of conducting a phenome-wide association study to characterize phenotypic abnormalities associated with individuals at high risk for lung cancer using electronic health records. Materials and Methods We used the beta release of the All of Us Researcher Workbench with clinical and survey data from a population of 225 000 subjects. We identified 3 cohorts of individuals at high risk to develop lung cancer based on (1) the 2013 U.S. Preventive Services Task Force criteria, (2) the long-term quitters of cigarette smoking criteria, and (3) the younger age of onset criteria. We applied the logistic regression analysis to identify the significant associations between individuals’ phenotypes and their risk categories. We validated our findings against a lung cancer cohort from the same population and conducted an expert review to understand whether these associations are known or potentially novel. Results We found a total of 214 statistically significant associations (P < .05 with a Bonferroni correction and odds ratio > 1.5) enriched in the high-risk individuals from 3 cohorts, and 15 enriched in the low-risk individuals. Forty significant associations enriched in the high-risk individuals and 13 enriched in the low-risk individuals were validated in the cancer cohort. Expert review identified 15 potentially new associations enriched in the high-risk individuals. Conclusions It is feasible to conduct a phenome-wide association study to characterize phenotypic abnormalities associated in high-risk individuals developing lung cancer using electronic health records. The All of Us Research Workbench is a promising resource for the research studies to evaluate and optimize lung cancer screening criteria.

AbstractAlthough it is well established that human cytochrome P450 1 family enzymes are induced by cigarette smoking through activation of the Ah receptor, it is not known whether this leads to increased metabolic activation or detoxification of carcinogenic polycyclic aromatic hydrocarbons (PAH), which are present in cigarette smoke and the general environment. We gave oral doses of deuterated phenanthrene ([D10]Phe), a non-carcinogenic surrogate of carcinogenic PAH such as benzo[a]pyrene, to smokers (N = 170, 1 or 10 μg doses) and non-smokers (N = 57, 1 μg dose). Bioactivation products (dihydrodiol and tetraol) and detoxification products (phenols) of [D10]Phe were determined in 6-h urine to obtain a comprehensive metabolic profile. Cigarette smoking increased the bioactivation of [D10]Phe and decreased its detoxification resulting in significantly different metabolic patterns between smokers and non-smokers (P < 0.01), consistent with increased cancer risk in smokers. The Phe bioactivation ratios ([D10]PheT/total [D9]OHPhe) were significantly higher (2.3 (P < 0.01) to 4.8 (P < 0.001) fold) in smokers than non-smokers. With solid human in vivo evidence, our results for the first time demonstrate that cigarette smoking enhances the metabolic activation of Phe, structurally representative of carcinogenic PAH, in humans, strongly supporting their causal role in cancers caused by smoking. The results suggest potential new methods for identifying smokers who could be at particularly high risk for cancer.

1610 Background: Low dose computed tomography (LDCT) scans have reduced lung cancer deaths by 20.3% in high risk populations, although there is an unknown balance between the benefits and harms of LDCT scans as a screening tool. Our purpose was to compare health-related QOL issues among lung cancer patients who were initially detected by LDCT scans; 4 comparison groups included: lung cancer diagnosed by a screening chest X-ray, as an incidental finding from procedures taken for other medical reasons, or based on symptoms indicative for lung cancer and routinely diagnosed, and individuals who were LDCT screened but found no lung cancer (controls who participated in Mayo’s lung cancer CT screening trial). Methods: A total of 1,658 lung cancer patients (cared at Mayo Clinic) in the 4 groups (37, 151, 389, and 1081 respectively) and 488 controls were compared on following patient-reported outcomes (collected via validated tools): overall QOL, four symptoms (cough, pain, dyspnea, fatigue), mental/ physical/ emotional/ social/ spiritual QOL, and other concerns (e.g., family/ friends/ financial/ legal). A clinically significant deficit was defined as at least 10-points in difference (or <50 points) on a 0-100 scale. The rates of deficits were compared via Fisher’s exact tests and average QOL values via Kruskal-Wallis tests. Results: Overall QOL and individual symptoms were significantly worse (p<0.05) in all lung cancer groups than in controls, except for pain. LDCT-screened patients reported the greatest deficit among the 4 lung cancer groups in physical (41%), emotional (24%), social (38%), and spiritual QOL (24%); whereas chest X-ray detected patients had the least deficit in overall QOL (22%) and pain (32%). All 4 lung cancer groups experienced much worse fatigue (52-64%) than the controls (32%). Conclusions: Our preliminary results suggest that LDCT-screening detected lung cancer patients reported a different QOL profile from other lung cancer patients and non-lung cancer controls. The clinical course, smoking behavior, and QOL related health issues associated with LDCT screening for lung cancer warrant thorough investigation.

Background: Bronchial carcinoid often appears hypervascular on bronchoscopic visualization and may be associated with hemoptysis. The diagnostic yield and bleeding complications associated with bronchoscopic biopsy of bronchial carcinoid tumors remain unclear. Materials and Methods: Patients with bronchial carcinoid tumors that were bronchoscopically visualized and biopsied at our tertiary referral medical center, over an 8-year period from 2010 to 2017, were retrospectively identified and reviewed to assess diagnostic yield and bleeding complications. Correlations with patient characteristics and carcinoid tumor features were analyzed. Results: Forty-nine patients were included (57% female). Tumors were predominantly (71%) located in proximal airways (mainstem and lobar bronchi). Bronchoscopic biopsy was diagnostic in 45 patients (92%). Thirteen patients (27%) experienced moderate (n=12, 25%) or severe (n=1, 2%) bleeding. Among these, 6 tumors (46%) had a vascular appearance and 4 patients (31%) had experienced recent hemoptysis. However, neither vascularity nor hemoptysis was associated with bleeding at biopsy (P=0.68 and 0.73, respectively). Carcinoid tumors were classified as typical in 79% and atypical in 21% with no difference in diagnostic yield or bleeding risk (P=0.28 and 0.92, respectively). Tumor size was also not associated with increased diagnostic yield or bleeding risk (P=0.54 and 0.39, respectively). Conclusion: Bronchoscopic biopsy of endobronchial carcinoid is associated with a high diagnostic yield and severe bleeding is rarely encountered. Diagnostic yield and bleeding seemed independent of vascular tumor appearance or history of recent hemoptysis.