Impact of the COVID-19 pandemic on cancer screenings in Portugal

Objectives: This study aimed to evaluate the impact of the COVID-19 pandemic on cancer screening in Portugal, and its consequences on cancer morbidity and mortality. Methods: The pre-pandemic and pandemic periods were compared using publicly available data on performance and health outcomes indicators of the Portuguese NHS, namely the numbers and proportions of eligible individuals who underwent cancer screening (breast, cervical or colorectal). Pre-pandemic data were modelled to project hypothetical scenarios without a pandemic using an exponential smoothing algorithm, and then compared with data collected during the COVID-19 pandemic. A Markov model was developed to estimate years of life lost (YLL) due the reduction in the number of cancer screenings during the pandemic. The MS Excel and the PRISM symbolic model checker software were used. Results: There was a decrease in the number of breast (13 %), cervical (15 %) and colorectal (9-11 %) cancers screenings during the first two years of the pandemic. The model projections are 506, 41, and 148 additional deaths, losses of 11, 6, and 4 months of life per patient, and 12.8 thousand, 576, and 4 thousand YLL by the population due to breast, cervical, and colorectal cancer, respectively, over a 25-year time horizon in Portugal. Conclusions: The disruption in cancer screening may contribute to increase cancer morbidity and mortality, with significant YLL. The long-term implications of the impaired cancer screening should be assessed, and proactive measures put in place to mitigate the increase in cancer morbidity, and mortality associated with the COVID-19 pandemic.