Cancer Diagnosis Rates Saw Improvement in 2021, But 2020 Gaps Persist
During the COVID-19 pandemic, healthcare systems across the U.S. experienced severe disruptions, and one critical area affected was cancer screenings and detection programs. These interruptions led to a significant decline in cancer diagnoses, which began in 2020 and continued into 2021, leaving a long-lasting impact on patients.
In 2020, cancer incidence dropped by 13% across all cancer types, with certain sites and stages experiencing even steeper declines. A recent study published in JAMA Network Open Oncology explored how these pandemic-related disruptions influenced cancer diagnosis rates in both 2020 and 2021.
The Study Overview
This population-based study used data from the Surveillance, Epidemiology, and End Results (SEER-22) Registries Database, covering nearly 48% of the U.S. population. Researchers analyzed records of individuals diagnosed with invasive cancer between January 1, 2000, and December 31, 2021.
The SEER-22 data revealed a total of 1,578,697 cancer cases reported in 2020 and 2021, with an almost even split between male (50.6%) and female (49.4%) patients. Among those diagnosed, about 58% were aged 65 years or older. Additionally, the study examined social and demographic factors such as ethnicity, age, gender, cancer stage, and whether the individual lived in an urban or rural area.
Overall Cancer Incidence Trends
The primary goal of the study was to assess changes in cancer diagnosis rates in 2020 and 2021 compared to pre-pandemic expectations. In 2020, cancer incidence was 9.4% lower than projected, while in 2021, the rates remained 2.7% below expectations. This analysis suggests that an estimated 149,577 cancer cases went undiagnosed during these two years, with 33,226 of those likely occurring in 2021.
While diagnosis rates saw some recovery in 2021, they didn’t fully return to pre-pandemic levels, particularly for certain cancers.
Site-Specific Declines
Eleven major cancer types were assessed in the study, and five of them—lung, cervical, urinary bladder, non-Hodgkin lymphoma, and kidney cancers—continued to show lower-than-expected diagnosis rates in 2021. Lung and cervical cancer diagnoses, in particular, were still 9% and 4.5% lower than anticipated, respectively, even after the peak of the pandemic had passed.
Cancer Screening Recovery
For cancers where routine screening is commonly recommended, recovery was mixed. Breast cancer screenings in women improved significantly in 2021, with diagnoses exceeding expected levels by 2.5%. Colorectal cancer screenings also rebounded to pre-pandemic rates by 2021.
However, other cancers, particularly lung and cervical cancers, continued to be diagnosed at lower rates due to delays in screenings. Women, younger individuals, and those from certain ethnic groups (Asians and Pacific Islanders) saw better recovery in cancer diagnosis rates compared to older adults and specific minority groups.
Cancer Stage and Risk Factors
In 2020, cancer incidence was down across all stages, with early-stage cancers experiencing an 11.9% drop and advanced-stage cancers falling by 6.4%. Fortunately, by 2021, diagnoses for both early and advanced cancers returned to expected levels in most cases. However, the diagnosis of advanced cervical cancer continued to lag behind pre-pandemic projections.
The study highlighted that people 65 and older, men, and specific racial groups, such as non-Hispanic Blacks and Hispanics, were more likely to experience missed cancer diagnoses. Conversely, younger women were least affected by these disruptions in overall cancer detection rates.