Fifteen-Year Follow-Up of the NYU Lung Biomarker Screening Cohort: Indolent-Prevalent Screen-Detected Lung Cancers Demonstrate a Less Aggressive Form of Pulmonary Malignancy

Abstract

SESSION TITLE: Advances in Lung Cancer SESSION TYPE: Original Investigation Slide PRESENTED ON: Wednesday, November 1, 2017 at 08:45 AM - 10:00 AM PURPOSE: Low-dose computed tomography (CT) for lung cancer screening is recommended in high-risk individuals to reduce lung cancer mortality. In our lung cancer screening cohort, we previously classified and characterized three groups of screen-detected lung cancers. “Incident (I)” cancers were defined as nodules not present on baseline CT-scan, but apparent on subsequent CT-scans. “Prevalent (P)” cancers were nodules documented at baseline CT and diagnosed as malignant within 6 months of the initial scan. “Indolent-prevalent (Id-P)” cancers were also present at baseline, but diagnosed after 6 months. In this update to our 2012 publication, we compared the baseline demographics, nodule characteristics, and clinical outcomes of these three sub-classifications of screen-detected cancers. METHODS: Since 2001, the NYU Lung Cancer Biomarker Center has conducted a longitudinal lung cancer biomarker discovery trial that included low-dose CT screening of high-risk individuals over the age of 50, with more than 20 pack-year smoking history, and living in an urban setting. Analysis included only patients with screen-detected lung cancer that have data to sub-classify them in this cohort study and report risk factors, prognosis, and subtypes of lung cancer. Mann-Whitney statistical analysis was used. RESULTS: A total of 1519 study subjects were enrolled from 2001 to 2016. We diagnosed 59 cancers in 56 patients. There were 42 adenocarcinomas, 4 small cell, 3 squamous-cell, 1 mesothelioma, and 9 “other” lung cancers. There were 29 Id-P cases, 20 P cases, and 10 I cases. While most Id-P and P cases were diagnosed at stage I-II (80% and 75%, respectively), most I cases were diagnosed at later stage (III-IV, 55%). The 1-year and 5-year survival rate at all stages for Id-P cases were 100% and 92%, respectively, while in P cases, 1-year and 5-year survival rates were both 85%. Recurrence rates were not statistically different between Id-P and P cases. There was more adenocarcinoma in-situ/lepidic predominant subtype (50%) in Id-P cases, more acinar predominant subtype (40%) in P cases, and no dominant subtype in I cases. Id-P cancers were more likely to be solid nodules compared with P cancers (p=0.05). On average, Id-P cancers were diagnosed 5.4 years after initial nodule detection and grew at a rate of 1.7mm per year. CONCLUSIONS: The three sub-classifications of screen-detected lung cancers have different histological subtypes and prognoses. Id-P screen detected lung cancers appear to have a less aggressive growth pattern despite being more likely to derive from solid nodules compared to P cancers. CLINICAL IMPLICATIONS: A better biological understanding of these three sub-classifications of screen-detected lung cancers may help us identify who may need further screening and improve screening intervals. DISCLOSURE: The following authors have nothing to disclose: Jiwoon Chang, Christopher Laboe, Myah Draine, Jamie Bessich, Gaetane Michaud, Daniel Sterman, William Rom, James Tsay No Product/Research Disclosure Information