A new University of Kentucky Markey Cancer Center study reveals that cancer diagnosis rates in the U.S. remained below expected levels in 2021, adding to the backlog of undiagnosed cases from 2020 due to the COVID-19 pandemic. 

The research, published in JAMA Network Open, found that observed cancer incidence rates were 2.7% lower than expected in 2021, following a 9.4% reduction in 2020. This translates to nearly 150,000 potentially undiagnosed cancer cases over the two-year period. 

While there was some recovery in 2021, cancer diagnoses were still not back to where they should be, says Todd Burus, senior author of the study and member of the UK Markey Cancer Center's Community Impact Office.  

“Unfortunately, this research shows that rates of cancer incidence in the U.S. have not rebounded as well as we would have hoped after the second year of the pandemic, Burus said. “While we still don’t know what impact this will have on long-term outcomes, prolonged disruptions in diagnoses of certain cancers are certainly concerning and something that needs to be addressed.” 

The study, led by Burus and Krystle Lang Kuhs, Ph.D., co-leader of Markey's Cancer Prevention and Control Research Program, follows the team’s research published earlier this year, which estimate over 134,000 missed cancer diagnoses in the first 10 months of the COVID-19 pandemic in 2020. 

Key findings of the latest study, which analyzed data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, include:  

• Among 11 cancer types, five remained significantly underdiagnosed in 2021: lung, cervical, kidney, bladder and lymphoma.  

• Female breast cancer showed signs of recovery in 2021, with diagnosis rates exceeding expectations by 2.5%. 

• Cancer diagnosis rates returned to pre-pandemic levels among women, people under 65, and individuals of Asian and Pacific Islander descent. 

• Diagnoses remained lower than expected for men, people 65 and older, and Hispanic, Black, and White individuals. 

The research team expressed concern over the continued disruption in cancer diagnoses, especially for early-stage lung and cervical cancers, which are screenable cancers that respond well to treatment when caught early. 

“These findings underscore the critical need for targeted public health initiatives to boost screening rates,” said Kuhs. "Early detection remains our best tool in improving cancer outcomes." 

The research team also emphasized the importance of improving national cancer surveillance systems to enable quicker identification of and response to concerning trends in cancer diagnoses, potentially saving lives through earlier detection and treatment.