ASPO Abstracts
Outcomes of Long-term Interval Rescreening with Low-Dose CT for Lung Cancer in Different Risk Cohorts
Category: Early Detection & Risk Prediction
Conference Year: 2019
Abstract Body:
Purpose: To evaluate the incidence of lung cancer via low-dose CT (LDCT) in participantswith previously negative scans and to identify high-risk subpopulations. Methods: Individuals with negative baseline screening results from the Princess MargaretInternational Early Lung Cancer Action Program prior to 2009 underwent LDCT rescreening from 2015 to 2018.Individuals were contacted in order of decreasing risk, as determined by the Prostate, Lung, Colorectal, and OvarianCancer Screening Trial's PLCOM2012 6-year lung cancer risk-prediction model, and then categorized into three riskcohorts according to their baseline risks. The incidence of lung cancer in each risk cohort was determined andcompared. Chi-square testing was used for categorical variables and one-way ANOVA on ranks was used forcontinuous variables.Results: Of the 1261 participants we attempted to recontact, 359 patients returned for arescreening scan (mean of 7.6 years between scans). Participants were divided into low (<2%), moderate(≥2%-<3.5%), and high baseline risk (≥3.5%) cohorts. On average, those in the high-risk cohort compared to the moderateand low-risk cohorts were older (66 vs 62 and 59 years) and had a greater smoking history (54 vs 47 and 29pack-years), respectively. The incidence of cancer in the high-risk cohort was significantly higher than in themoderate-risk cohort (11% vs 1.7%, p=0.002). Conclusion: If rescreening efforts were prioritized to patients with a ≥3.5% 6-yearbaseline risk, a significantly higher incidence of lung cancer may be detected. Future studies will focus on theclinical benefit of rescreening patients who fall in the high-risk cohort and the management of patients in the moderateand low-risk cohorts.
Keywords: Low-dose CT, LungCancer Screening