Public Engagement with Lung Cancer Screening Information: Topic Modeling of Lung Cancer-Related Reddit Posts

Lung cancer screening (LCS) with low-dose computed tomography is an effective strategy for early detection and improved survival. Despite its clinical benefits, public engagement with LCS topic remains unclear, particularly in the digital health communities. This study examines the thematic landscape of lung cancer-related discussions on Reddit. Using Python's Reddit API Wrapper, we collected 109,868 posts from six lung cancer-related subreddits between January 2019 and December 2024. After preprocessing, 105,118 unique posts were analyzed using Latent Dirichlet Allocation topic modeling to identify emergent themes. Topics were qualitatively reviewed and categorized into four high-level themes: treatment, mental health, smoking, and LCS. Mental health (71.82%) and treatment (16.84%) dominated the discourse, followed by smoking (8.30%), while LCS remained underrepresented (3.04%). Despite an increase in overall engagement from 2022 onward, LCS-related posts remained sparse, with no sustained upward trend. Reddit users frequently discuss treatment and mental health concerns related to lung cancer but rarely engage with LCS as a topic, revealing a critical gap in public awareness. These findings highlight the need for targeted public health strategies to promote LCS awareness on social media platforms, leveraging the platforms' growing role in health communication.