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From the Journals

Cancer Diagnoses Lag Post-Pandemic, Study Reveals

Despite recovery efforts, U.S. cancer diagnoses remained 2.7% below expected levels in 2021, potentially leaving about 150,000 cases undetected over 2 years of COVID-19 pandemic–related disruptions.

Conexiant

A study published in JAMA Network Open revealed that cancer diagnoses in the United States remained below expected levels in 2021, compounding the deficit from 2020 during the first year of the COVID-19 pandemic.

The population-based cross-sectional study, led by researchers from the University of Kentucky, analyzed data from the Surveillance, Epidemiology, and End Results (SEER) 22 Registries Database, covering approximately 47.9% of the U.S. population.

The study analyzed 1,578,697 cancer cases reported between January 2020 and December 2021. Researchers used an ensemble forecasting model to estimate expected cancer incidence rates for 2020 and 2021 based on data from 2000 to 2019.

Key Findings

All-sites cancer incidence was 2.7% lower than expected in 2021 (95% prediction interval [PI] = 1.4%-3.9%), following a 9.4% reduction in 2020 (95% PI = 8.5%-10.5%).

An estimated 149,577 cancer cases (95% PI = 126,059-176,970) potentially went undiagnosed during 2020 and 2021 combined.

Significant reductions persisted in 2021 for lung cancer (9.1% lower; 95% PI = 6.4%-13.2%), cervical cancer (4.5% lower; 95% PI = 0.4%-8.0%), bladder cancer, kidney cancer, and non-Hodgkin lymphoma diagnoses.

Early-stage diagnoses for lung cancer (13.7% lower; 95% PI = 5.1%-23.5%) and cervical cancer (11.5% lower; 95% PI = 4.9%-18.6%) remained significantly reduced in 2021.

Female breast cancer was the only site to show significant recovery, exceeding expected diagnosis rates by 2.5% in 2021 (95% PI = 0.1%-4.8%).

Additional Results

  • All-sites cancer incidence rates:
    • 2020: 408.0 cases per 100,000 population
    • 2021: 438.3 cases per 100,000 population
  • Early-stage diagnoses:
    • 2020: 11.9% lower than expected (95% PI = 10.3%-13.5%)
    • 2021: 1.3% lower than expected (95% PI = 3.3% lower to 1.2% higher)
  • Late-stage diagnoses:
    • 2020: 6.4% lower than expected (95% PI = 4.5%-8.2%)
    • 2021: 1.4% lower than expected (95% PI = 3.7% lower to 0.8% higher)

Population subgroup analysis showed that by 2021, all-sites cancer incidence returned to prepandemic levels among female individuals, persons younger than 65 years, and non-Hispanic Asian and Pacific Islander individuals. However, rates remained significantly lower than expected among other demographic groups.

The study found substantial increases in diagnosis rates in March and April 2021, corresponding to when the first COVID-19 vaccines became widely available among the general adult population in the United States.

The study authors noted the need for immediate efforts to increase cancer screenings among eligible populations, particularly for lung and cervical cancers. They also called for improvements in national cancer surveillance efforts to enable faster detection and response to systemic problems in cancer diagnosis and care.

Limitations of the study included uncertainties in projecting expected cancer incidence rates, potential delays in case reporting, and the exclusion of cases without an available month of diagnosis (less than 1% of total cases).

Conflict of interest disclosures can be found in the study.