Cancer Detection Rates Dropped Due to COVID-19 Disruptions, Study Finds

Through the first year of the COVID-19 pandemic, cancer incidence rates dropped by 8.7% across all cancer sites in the United States, with the largest disruptions observed in lung and bronchus cancers, melanoma of the skin, and thyroid cancer.

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These findings suggest how a drop in cancer incidence, especially for earlier-stage disease, may lead to a larger surge in advanced disease in the long term.

This US population-based study published today in Health Affairs.

“The shift in presentation to later-stage disease during the pandemic suggests that patients generally deferred seeking cancer care unless there were clear signs of disease,” wrote the researchers of the study. “Indeed, glioblastoma, which is among the most aggressive and rapidly progressive cancers, was the only cancer type that did not experience a drop in reported incidence during the pandemic.”

In this study, the researchers used The Surveillance, Epidemiology, and End Results (SEER) data, the authoritative, population-based cancer registry of the United States, which includes approximately 48% of the US population. The SEER registry includes 44.7% of all Black, 59.9% of all American Indian/Alaska Native, 70.7% of all Asian, 70.3% of all Native Hawaiian/Pacific Islander, and 66.3% of all Hispanic patients in the United States.

Using SEER, the researchers compared the expected cancer incidence for 2020 in the absence of COVID-19 with the reported incidence in 2020 for all major cancer sites and subtypes to better understand the extent of the disruption in cancer detection associated with the pandemic. Additionally, further subgroup analyses were performed for the cancers that were in the highest quartile of incidence and the highest quartile of percentage difference in cancer detection. Subgroup analyses were also conducted for cancers that are “screening amenable” in the general population: cervical, breast, lung, and colorectal cancers.

The reported rates revealed 3 distinct trends in cancer incidence across 2000 to 2020, with the latest trend between 2013 and 2019 showing a 0.14% annual percent change (95% CI, –0.28% to 1.56%), suggesting that cancer incidence had been relatively stable. However, a significant drop in incidence rates occurred during the first year of the pandemic, with rates falling 8.7% (95% CI, –10.3% to –7.1%).

Additionally, female patient generally experienced a slightly lower drop in incidence than male patients (7.9% vs 8.7%), as well as younger patients compared with older patients (7.3% vs 9.2%). Furthermore, non-Hispanic Asian/Pacific Islander patients seemed to experience the largest drop in cancer incidence (12%) compared with all other racial or ethnic groups.

Most cancer sites experienced significant drops in incidence, except for glioblastoma, which had an estimated increase of 0.7%. The largest incidence drops were observed in thyroid cancer (papillary subtype, 18.9%; all subtypes, 16.9%), eye and orbit cancer (15%), and melanoma of the skin (15%). Furthermore, the high-burden cancers which experienced large disruptions by percent difference were lung and bronchus cancer (10.3%), melanoma of the skin (15%), and thyroid cancer (16.9%).

The researchers believe these findings may have major implications in both the near- and long-term future. First, they believe there could be an increase in cancer-related morbidity and mortality. They also believe the shift in presentation to later-stage disease, which was observed in the subgroup analyses, suggests that patients generally deferred seeking cancer care during the pandemic, unless there was a clear sign of disease. Furthermore, a drop in cancer incidence may evolve into a surge of more advanced disease in the long term.

“Screening-amenable cancers such as breast, colorectal, lung, and cervical cancer could be an especially fruitful area to concentrate efforts that seek to mitigate the impact of the COVID-19 pandemic, as reestablishing screening regimens for patients could not only identify cases ‘missed’ during the pandemic but also potentially do so at an earlier stage,” wrote the researchers. “Additional years of data would also be helpful to estimate more precisely the impact of the COVID-19 pandemic on rare cancers”

Reference

Kim U, Koroukian S, Rose J, et al. US cancer detection decreased nearly 9 percent during the first year of the COVID-19 pandemic. Health Affairs. Published online January 4, 2024.doi: 10.1377/hlthaff.2023.00767