Impact of the COVID-19 pandemic on diagnosis of new cancers: A national multicenter study of the Veterans Affairs Healthcare System

Abstract

Background: The coronavirus disease 2019 (COVID-19) pandemic caused disruptions in treatment for cancer. Less is known about its impact on new cancer diagnoses, where delays could cause worsening long-term outcomes. This study quantifies decreases in encounters related to prostate, lung, bladder and colorectal cancers, procedures that facilitate their diagnosis, and new diagnoses of those cancers in the COVID era compared to pre-COVID era.

Methods: All encounters at Veterans' Affairs facilities nationwide from 2016 through 2020 were reviewed. The authors quantified trends in new diagnoses of cancer and in procedures facilitating their diagnosis, from January 1, 2018 onward. Using 2018 to 2019 as baseline, reductions in procedures and new cancer diagnoses in 2020 were estimated. Calculated absolute and percentage differences in annual volume and observed-to-expected volume ratios were calculated. Heat maps and funnel plots of volume changes were generated.

Results: From 2018 through 2020, there were 4.1 million cancer-related encounters, 3.9 million relevant procedures, and 251,647 new cancers diagnosed. Compared to the annual averages in 2018 through 2019, colonoscopies in 2020 decreased by 45% whereas prostate biopsies, chest computed tomography scans, and cystoscopies decreased by 29%, 10%, and 21%, respectively. New cancer diagnoses decreased by 13% to 23%. These drops varied by state and continued to accumulate despite reductions in pandemic-related restrictions.

Conclusion: The authors identified substantial reductions in procedures used to diagnose cancer and subsequent reductions in new diagnoses of cancer across the United States because of the COVID-19 pandemic. A nomogram is provided to identify and resolve these unmet health care needs and avoid worse long-term cancer outcomes.

Lay summary: The disruptions due to the COVID-19 pandemic have led to substantial reductions in new cancers being diagnosed. This study quantifies those reductions in a national health care system and offers a method for understanding the backlog of cases and the resources needed to resolve them.

Keywords: bladder cancer; cancer diagnosis; cancer screening; colorectal cancer; coronavirus disease 2019 (COVID-19); lung cancer; prostate cancer.

Figure 1

Temporal trends in (A) cancer encounters and (B) diagnostic and screening procedures in the VA health system from 2018 to 2020. The estimated (C) monthly and (D) cumulative deficit in procedures based on 2018 to 2019, seasonally adjusted baseline is presented. The gray, shaded region indicates the pre‐pandemic era, defined as before March 11, 2020. CT indicates computed tomography; FOBT, fecal occult blood test; VA, Veterans Health Administration.

Figure 2

Heatmap of the change in the number of diagnostic and screening procedures performed for cancer in 2020 compared to 2018 through 2019 baseline in each state for (A) prostate biopsy, (B) chest CT scan, (C) cystoscopy, and (D) colonoscopy. Green states represent a relative increase in procedures performed in 2020, and pink indicates a relative decrease in procedures performed. Gray indicates no data for that state. CT indicates computed tomography (includes both screening and diagnostic).

Figure 3

Funnel plot of observed to expected number of diagnostic and screening procedures performed for cancer in 2020 by expected number of procedures (based on 2018‐2019 data) per state for (A) prostate biopsy, (B) chest CT scan, (C) cystoscopy, and (D) colonoscopy. CT indicates computed tomography (includes both screening and diagnostic). Selected states labeled. Red lines represent 95% confidence intervals.

Figure 4

Temporal trends in new cancer diagnoses in the VA health system from 2018 to 2020 are presented as (A) monthly cases and (B) percentage of seasonally adjusted baseline. The estimated (C) monthly and (D) cumulative number of undiagnosed cancers in 2020. The gray, shaded region indicates the pre‐pandemic era, defined as before March 11, 2020. VA indicates the Veterans Health Administration.

Figure 5

Nomogram to calculate the relationship between unperformed cases, potential monthly capacity above baseline, and months needed to clear all unperformed cases. Formula: Monthly percent increase in volume to clear unperformed cases = unperformed cases as percent of monthly baseline/months to clear unperformed cases. Example (red line): From April 1, 2020, to October 1, 2020 (6 months), we performed 50% of our expected monthly volume of colonoscopies. We have a backlog of 300% of our monthly volume: 6 × 50 = 300%. We can perform up to 125% of our expected monthly volume of colonoscopies, an additional 25%. We connect the 25 on the far‐left line with 300 on the middle line using a straight edge to calculate that it will take us 12 months to clear these unperformed cases. Alternatively, we calculate that we have an unperformed case load of 300% of our monthly volume. We want to clear these cases within 1 year or 12 months. We connect the 12 on the far‐right line with 300 on the middle line using a straight edge to calculate that it will take an increased volume of 25% to clear these cases in the desired time period.