Cancer Screening Tests Rebound Following First Peak of COVID-19 Pandemic

After a dramatic decrease during the first peak of the COVID-19 pandemic, a substantial increase in cancer screening procedures during more recent time periods has been reported, according to data from a research letter published in Cancer Cell.

After a dramatic decrease during the first peak of the COVID-19 pandemic, a substantial increase in cancer screening procedures during more recent time periods has been reported, according to data from a research letter published in Cancer Cell.1

Compared to pre-pandemic times, defined as December 2019 to March 2020, an increase in tests performed during period 7, defined as September 2020 to December 2020, was noted across all types of screening analyzed, with the exception of colonoscopy.

Specifically, these increases ranged from 2.0% for the Papanicolaou test to 24.0% for the prostate-specific antigen test. In this same time range, an increase in positive diagnoses was also observed across all categories, except for colonoscopy; that increase ranged from 1.0% to 38.0%.

During period 7, the number of colonoscopy tests dropped by 15.0%, and the number of associated diagnoses also dropped by 30.0% when compared with pre-pandemic times. A reduction in the number of screening tests was reported during periods 5 and 6, defined as March 2020 to June 2020 and June 2020 and September 2020, respectively; this decrease ranged from 65.0% to 82.0%, respectively, and 4.0% to 44.0%, respectively.

Moreover, significant shifts were observed with regard to racial distribution of patients undergoing mammography in period 6, defined as June 2020 to September 2020, and period 7, defined as September 2020 to December 2020, vs 3 months pre-pandemic. Higher proportions of non-Hispanic White patients were noted in these 3 time periods, at 83.2% and 82.0% vs 79.0%, respectively (P < .001). Lower proportions of non-Hispanic Blacks were noted, at 5.2% and 5.3% vs 6.3%, respectively (P < .001), as well was Hispanic/Latino patients, at 2.4% and 2.6% vs 3.3% (P < .001).

The racial disparities were illustrated by reduced numbers of non-Hispanic Black and Hispanic patients undergoing mammography during period 7 (n = 1774 and n = 867, respectively) vs the 3 months before the pandemic (n = 1859 and n = 977, respectively; this contrasted with the increase in mammography tests in the whole group of patients analyzed. This finding was further validated by comparably significant shifts observed during periods 6 and 7 vs other pre-pandemic time periods.

“Although the overall increase in screening examinations is reassuring, the decrease in colonoscopy has yet to compensate,” the study authors wrote. “This highlights the importance of home-based alternatives for colon cancer screening in such particular situations. Racial disparities appear to differ between screening procedures, and they are more marked in patients undergoing mammography. Efforts to address these gaps are strongly required to ensure timely and equitable care across the patient population.”

The COVID-19 pandemic underscored pre-existing health disparities between socioeconomic and ethnic groups. However, it remains unclear whether changes in screening tests could disproportionately impact marginalized communities.

As such in this study, investigators set out to evaluate temporal changes in cancer screening tests and diagnoses in the Massachusetts General Brigham System. They also examined socioeconomic, racial, and ethnic features of patients who underwent screening during the pandemic.

Investigators examined cancer screening tests and diagnoses during 7 periods of 3 months: period 1 (March 2, 2019 to June 2, 2019), period 2 (June 3, 2019 to September 2, 2019), period 3 (September 3, 2019 to November 30, 2019), period 4 (December 1, 2019 to March 2, 2020), period 5 (March 2, 2020 to June 2, 2020), period 6 (June 3, 2020 to September 3, 2020), and period 7 (September 4, 2020 to December 5, 2020). The first pandemic peak was period 5 and the second peak was period 7.

Investigators looked at the following screening tests: mammography, PSA, colonoscopy, Papanicolaou test, and low-dose CT scan. To calculate the percent of change in screening tests and diagnoses during pandemic periods vs period 4 was calculated as (Nperiod – Ncontrol)/Ncontrol.

To calculate the corresponding 95% Cis, investigators utilized the Clopper-Pearson method.

To assess the impact of socioeconomic disadvantages on cancer screening, investigators used the Area Deprivation Index (ADI). A higher score translated to a greater disadvantage. To identify a patients’ national ADI, investigators used the Neighborhood Atlas. Pairwise comparisons of gender, age, race, and ADI percentiles between the time periods were calculated.

A total of 382,858 patients underwent cancer screening tests, and the mean age of these patients was 59.9 years (standard deviation, 12.3 years). Just more than half, or 58.6%, were female and the majority (80.1%) were non-Hispanic White.

After a significant decrease in screening from March 2020 to June 2020 (n = 15,453 vs n = 60,344 in period 1 and n = 57,502 in period 2), the highest number of tests were noted during period 7 (n = 72,156), thus surpassing the number reported in the pre-pandemic period (n = 64.269). A comparable trend was showcased with regard to subsequent diagnoses. During the early pandemic, 1,985 positive tests were reported vs 3,476 positive tests in period 7 and 3,423 tests from December 2019 to March 2020.

When examining the different periods prior to the pandemic, periods 1 through 4, more socioeconomic disadvantage observed in those who were screened in period 5, defined as March 2020 to June 2020, in relation to period 4, defined as December 2019 to March 2020.

Additionally, a more favorable socioeconomic status was observed in patients screened in periods 6 and 7, defined as June 2020 to December 2020. Significant changes were noted compared with each of the 4 pre-pandemic periods. The shift in status was reported most importantly in patients who were undergoing mammography and colonoscopy.

Age variation was modest between the different time periods that were evaluated across the screening categories; the standardized mean difference ranged from 0.002 and 0.37 for all pairwise comparisons. Moreover, no difference in gender distribution was noted with regard to colonoscopy and low-dose CT scan in the pandemic time periods vs the preceding periods.

“We identified racial disparities within mammography testing from June to December 2020, with a significant decrease in the proportion of Black and Hispanic patients,” the study authors wrote. “In light of previously established low screening rates in ethnic minorities, these findings are concerning and suggest the pandemic may accentuate racial disparities related to cancer screening.”


  1. Labaki C, Bakouny Z, Schmidt A, et al. Recovery of cancer screening tests and possible associated disparities after the first peak of the COVID-19 pandemic. Cancer Cell. 2021;39(8):1042-1044. doi:10.1016/j.ccell.2021.06.019