Impact of the COVID-19 Pandemic on Lung Cancer Screening and Diagnosis: A Systematic Review

Background/Objectives: The global health crisis of the COVID-19 pandemic in 2020 severely impacted healthcare systems, particularly affecting cancer patients, including those with lung cancer. Understanding the pandemic's effects on lung cancer diagnosis is important for providing guidelines for future similar crises. Methods: A comprehensive search was conducted using the SCOPUS and PubMed databases, including keywords such as 'COVID-19 pandemic,' 'lung cancer,' 'diagnosis,' and 'screening.' In the initial screening phase, studies were selected based on their title and abstract, followed by the removal of duplicates. A second round of full-text screening was then performed using predefined inclusion and exclusion criteria. Specific checklists were applied to ensure methodological quality. Results: Out of 564 articles, 78 met the inclusion criteria and were grouped according to changes in lung cancer incidence, screening and diagnostic procedures, and staging during the COVID-19 pandemic compared to pre-pandemic. Multiple studies reported an average decline of 20% in newly diagnosed lung cancer cases, alongside significant decreases in screenings, follow-ups, and diagnostic procedures. In contrast, only two studies reported an increase in lung cancer incidence, and three studies reported increases in screening or diagnostic activity. Eight studies reported a shift toward more advanced-stage diagnoses and fewer early-stage detections, while four studies observed a decrease in advanced-stage lung cancer during the pandemic compared to pre-pandemic years. Conclusions: Studies show that overall, the COVID-19 pandemic disrupted lung cancer diagnosis in many countries, highlighting the need for stronger healthcare systems that can support crisis response and equitable care.