Abstract
BACKGROUND: Studies have shown COVID-19 pandemic led to excess mortality globally. However, reports on specific leading causes of death are limited. This study used statewide data to evaluate excess cancer-related death by comparing the expected and observed cancer-related deaths during the first two years of pandemic. METHODS: 2015-2021 Nevada statewide death certificates and Nevada State Demographer's population data were analyzed. We evaluated three outcomes of cancer mortality: cancer as the underlying cause of death, cancer as a contributing cause of death, and a combination of both. Causes of death were determined and provided by the NCHS (ICD-10, 2019 version). Negative binomial regressions were used to model cancer deaths to compare the baseline prior to COVID-19 (2015-2019) with the COVID-19 pandemic period (2020-2021). Observed to expected (O/E) ratios and corresponding confidence intervals were calculated. RESULTS: During 2020-2021, overall cancer-related deaths, combining underlying and contributing causes of death, were 208 cases lower than expected (O/E = 0.98; 95% CI: 0.96-1.00; p = 0.053), with a notably reduced mortality for respiratory system cancers (O/E = 0.86; 95% CI: 0.83-0.90; adjusted p < 0.001). For cancer as the underlying cause of death, deaths were 550 cases lower than expected (O/E = 0.95; 95% CI: 0.93-0.97; p < 0.001). In contrast, for cancer as a contributing cause of death, deaths were 189 cases higher than expected (O/E = 1.23; 95% CI: 1.20-1.27; p < 0.001). CONCLUSION: Cancer-related mortality, combining underlying and contributing cause of death, showed a modest decline during the COVID-19 pandemic (2020-2021), primarily driven by fewer deaths related to respiratory system cancers. The causes for the cancer-related mortality reduction could result from the mortality shifting from cancer to COVID-19, lack of diagnosis, and omissions or misclassification in death certification during the pandemic. Future research incorporating data from subsequent years is needed to better monitor and understand changes in cancer mortality during the pandemic.