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 SEER-22 registries, which encompass approximately 50% of the U.S. population. We investigated changes in monthly incidence rates stratified by various factors, including cancer type, stage, age group, sex, race/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 to April 2019, the incidence rates in April 2020 dropped by 48.1% and did not consistently return to pre-pandemic levels. The reduction in cancer rates was more pronounced in urban and affluent counties. Across all cancer types, there was a 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 cancer (54.1%). Furthermore, these decreases were primarily observed in early-stage rather than late-stage disease.
Conclusions
The COVID-19 pandemic had a significant impact on cancer outcomes. Monitoring long-term consequences of the pandemic on cancer incidence, stage at diagnosis, and mortality trends will be crucial.