Abstract Rationale Pleural mesothelioma (PM) is a rare malignancy affecting the serosal lining of the thoracic cavity and lungs, with treatment advancements including dual immunotherapy with nivolumab and ipilimumab. The COVID-19 pandemic, which began in 2019, disrupted healthcare systems globally, raising concerns about its impact on the diagnosis, treatment, and survival outcomes of patients with PM. Previous studies from Italy and the Netherlands observed a decline in PM diagnoses and chemotherapy use during the pandemic. However, the impact on survival and treatment patterns in the United States remains unclear,. In this study, we evaluated the impact of the COVID-19 pandemic on the incidence, stage at diagnosis, treatment patterns, and survival outcomes of patients with pleural mesothelioma in the United States between 2018 and 2022, with the goal of determining whether pandemic-related healthcare disruptions affected patient care and outcomes. Methods A retrospective study was conducted using the National Cancer Institute’s SEER 17 database, covering 26.5% of the U.S. population. Adult patients diagnosed with PM between 2018 and 2022 were included. Data on patient demographics, treatment patterns, disease stage, and survival outcomes were analyzed. Kaplan-Meier curves and Cox proportional-hazards models were used to assess survival, adjusting for covariates such as sex and histology. Results Between 2018 and 2022, the PM incidence rate showed annual fluctuations, with a 13.5% decrease in 2020, followed by a 6.5% increase in 2021. Treatment patterns remained largely unchanged over the study period. The median overall survival was lowest in 2020 (9.0 months), compared to 2019 (13.0 months) and 2018 (11.0 months). Multivariable analysis indicated that male sex and 2020 diagnosis were associated with a higher risk of death, with a hazard ratio of 1.41 (95% CI 1.27-1.57, p 0.001) and 1.13 (95% CI 1.00-1.27, p = 0.048), respectively. Conclusion The COVID-19 pandemic significantly affected the incidence of PM, with a notable decline in 2020, and worsened overall survival outcomes for patients diagnosed during this period. Although treatment protocols remained stable, delays in diagnosis, potential misdiagnoses, and healthcare disruptions likely contributed to the observed decline in survival. These findings underscore the need for timely diagnosis and uninterrupted care for cancer patients, even during global health crises. Further research is needed to assess long-term trends and the impact of emerging treatments like dual immunotherapy on survival outcomes in the post-pandemic era. This abstract is funded by: None
Smesseim et al. (Fri,) studied this question.