Reduced breast and lung cancer screening rates in the U.S. during COVID pandemic

By Dr. Chinta SidharthanFeb 8 2023Reviewed by Benedette Cuffari, M.Sc.

In a recent study published in the journal JAMA Network Open, researchers determined whether the rates for cancer screening tests, such as mammograms for breast cancer and low-dose computed tomography (CT) for lung cancer, decreased during the coronavirus disease 2019 (COVID-19) pandemic.

Study: Breast and Lung Cancer Screening Among Medicare Enrollees During the COVID-19 Pandemic. Image Credit: New Africa / Shutterstock.com

Cancer screening during the pandemic

Social distancing and movement restrictions implemented during the COVID-19 pandemic reduced cancer screening test rates, as these procedures would have required interactions at close quarters. As a result, during the early stages of the pandemic, the number of cancer diagnoses also decreased. However, soon after, cancer screening and diagnosis rates soon recovered and returned to near-normal levels by late 2020.

However, the cancer screening rates beyond 2020 have not been studied in detail. Some reports indicate that the rates declined again during the first two months of 2021.

Most existing reports are from hospitals or single institutions and have conflicting results. Furthermore, many studies assessing cancer screening rates did not consider their temporal trends before the onset of the COVID-19 pandemic.

About the study

In the present study, researchers used 20% of enrollment and claims data by Medicare beneficiaries between March 2016, and April 2022, with updates extending to October 14, 2022. The data included summary files, inpatient claims, skilled nursing facility claims, Medicare carrier files, and outpatient claims.

For a descriptive analysis of cohorts, 64 monthly cohorts were formed based on Medicaid recipients who were alive on the first of every month between January 2017 and April 2022. While the mammography cohort comprised only females between the ages of 50 and 74, the low-dose CT cohort consisted of enrollees of both genders between the ages of 55 and 79.

Five regression analysis cohorts were also constructed that spanned 12 months from March of each year to the end of February of the following year between 2017 and 2022. Only participants who completed Medicare reports and those who did not enroll in the health maintenance organization for one year preceding and succeeding the study period were included in the analysis. The Agency for Healthcare Research and Quality (AHRQ) comorbidity scores from previous years' claims were also obtained.

Information on age, gender, ethnicity and race, education levels, and whether the patient had a specific primary care physician were obtained from Medicare enrollment records and the 2019 United States Census Bureau community survey estimates. The receipt of bilateral mammograms and low-dose CT scans were the measured outcomes.

Delayed mammograms and lung CT screening between 2020 and 2021

A continued decrease in cancer screening rates was observed from 2021 until early 2022. Notably, this reduction in screening rates was not uniformly lower across this period.

Mammography and low-dose CT rates during some months were close to predicted values, while, during other months, these rates were lower than expected. For low-dose CT rates, the periods when the rates were lower than anticipated coincided with periods when COVID-19 case numbers surged in the U.S.

The analysis of pre-pandemic cancer screening rates indicated that mammography rates were constant between 2017 and early 2020. At the same time, low-dose CT rates exhibited a monotonic increase from 500 scans/million individuals each month in 2017 to 1,100 scans/million individuals in early 2020.

Between March 2020 to February 2021, low-dose CT and mammography rates were 24% and 17% below the expected rates, respectively. Between March 2021 and February 2022, the rates were 14% and 4% lower than expected, respectively.

Low income, determined from the Medicaid eligibility information, and races and ethnicities historically considered marginalized had lower pre-pandemic cancer screening rates. Individuals belonging to these groups also showed slower recovery in screening rates after the pandemic-associated decline.

Conclusions

The current study evaluated the COVID-19 pandemic-associated reduction in cancer screening rates in the U.S. by analyzing mammography and low-dose CT rates between 2017 and 2022.

While there was a decrease in screening rates due to the pandemic, this decrease was not uniform. For example, some months showed close to predicted breast and lung cancer screening rates, whereas other months, which had lower-than-expected rates, coincided with periods when COVID-19 cases surged in the U.S.

Delays in cancer screening can result in the delayed detection and diagnosis of cancer in its early stages, thereby worsening the prognosis for many patients. While widespread COVID-19 vaccination reduces infection risks and improves clinical conditions to resume cancer screening at pre-pandemic levels, the current study's authors also recommend the increased use of home-testing kits for certain cancers, such as cervical and colorectal cancers.