Cancer and COVID-19: US cancer incidence rates during the first year of the pandemic.

Background: The COVID-19 pandemic has had a profound global impact on health-care systems and patient outcomes. However, the specific effects of the pandemic on cancer incidence rates in the United States during its initial year remain unknown.

Methods: In this study, we analyzed data from the Surveillance, Epidemiology, and End Results-22 registries, which encompass approximately 50% of the US population. We investigated changes in monthly incidence rates stratified by various factors, including cancer type, stage, age group, sex, race and ethnicity, socioeconomic status, rural-urban status, and registry locations. We compared the incidence rates observed during the pandemic with those from the previous year.

Results: Our findings revealed a decline in incidence rates for all cancer sites combined starting in March 2020, coinciding with the implementation of stay-at-home orders. This decline reached its lowest point in April 2020 and persisted at a lower level until May 2020. Notably, compared with April 2019, the incidence rates in April 2020 dropped by 48.1% and did not consistently return to prepandemic levels. The reduction in cancer rates was more pronounced in urban and affluent counties. Across all cancer types, there was a statistically significant decrease in incidence rates during the pandemic, with the largest declines observed in thyroid (71.2%), prostate (57.9%), breast (54.9%), and colon and rectum cancers (54.1%). Furthermore, these decreases were primarily observed in early stage rather than late-stage disease.

Conclusions: The COVID-19 pandemic had a statistically significant impact on cancer outcomes. Monitoring long-term consequences of the pandemic on cancer incidence, stage at diagnosis, and mortality trends will be crucial.