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Cosmos Study

Missed Cancer Screenings Not Yet Associated with Increased Cancer Rates or Severity

February 17, 2023
Dual-Team Study
Team A:Christopher Alban, MDSam Sahakian
Team B:Steve Allen, MDTed Stamp

Key Findings

  • Rates of cancer screening for breast cancer, cervical cancer, and colon cancer have returned to normal.
  • In data through December 31, 2022, we saw no significant increase in the number of new cancer diagnoses or how advanced or severe those cancer cases were, despite decreased screenings during the pandemic.

Previous studies have shown that cancer screening rates dropped at the start of the COVID-19 pandemic.1,2 The primary concern about this drop was that early cancer diagnoses might be missed, leading to a rise in rates of more advanced cancers. To evaluate the degree to which this might be true, we studied two related questions:

Following the drop of cancer screenings in the early pandemic:

  • Was there an increase in the number of cancer diagnoses?   
  • Was there an increase in advanced or severe cancers?

We evaluated 373,574 cancer diagnoses entered in patients’ charts between January 1, 2018, and December 31, 2022. We established a pre-pandemic baseline period from January 1, 2018, through December 31, 2019, and compared weekly diagnosis rates for the study period to that baseline.

There was a clear drop in cancer cases early in the pandemic, correlated with the decrease in screening. However, as screening rates returned to normal, cancer detection rates did as well. There was not a significant increase in the rate of cancer diagnoses in 2020-2022 as compared to pre-pandemic, as shown in Figure 1. Not only did rates of cancer diagnoses not rise significantly, but new diagnoses of advanced cancers also didn’t rise, as shown in Figure 2.

Figure 1
Weekly Cancer Screening and Diagnosis Volumes per 1 Million Patients
Weekly Cancer Screening and Diagnosis Volumes per 1 Million Patients
Figure 1. The darker, colored lines represent the number of weekly cases of cancers identified per 1 million patients, while the lighter, gray lines represent the number of weekly screenings for that type of cancer per 1 million patients. Both sets of lines show five-week rolling averages.
Figure 2
Weekly Cancer Screening and Advanced Cancer Diagnosis Volumes per 1 Million Patients
Weekly Cancer Screening and Advanced Cancer Diagnosis Volumes per 1 Million Patients
Figure 2. The darker, colored lines represent the number of weekly cases of advanced cancers identified per 1 million patients, while the lighter, gray lines represent the number of weekly screenings for that type of cancer per 1 million patients. Both sets of lines show five-week rolling averages.

While our data does not show an increase in advanced cancers, it might take years to fully realize the impact of missed screenings, especially for cancers with longer recommended intervals between screenings.

These data come from Cosmos, a HIPAA-defined Limited Data Set of more than 180 million patients from 190 Epic organizations including 1,123 hospitals and more than 22,500 clinics, serving patients in all 50 states and Lebanon. This study was completed by two teams that worked independently, each composed of a clinician and research scientists. The two teams came to similar conclusions.

References

  1. Sharp Declines in Breast and Cervical Cancer Screening. Centers for Disease Control and Prevention. https://www.cdc.gov/media/releases/2021/p0630-cancer-screenings.html
  2. Mast C, Deckert J, Muñoz del Rio, A. Troubling Cancer Screening Rates Still Seen Nearly Two Years into the Pandemic. Epic Research. https://epicresearch.org/articles/troubling-cancer-screening-rates-still-seen-nearly-two-years-into-the-pandemic. Accessed: February 7, 2023.