Effect of the SARS-CoV-2 pandemic on colorectal cancer diagnosis and prognosis

Abstract

Background and study aims: Our aim was to determine the impact of the SARS-CoV-2 pandemic on the diagnosis and prognosis of colorectal cancer (CRC).

Patients and methods: This prospective cohort study included individuals diagnosed with CRC between March 13, 2019 and June 20, 2021 across 21 Spanish hospitals. Two time periods were compared: prepandemic (from March 13, 2019 to March 13, 2020) and pandemic (from March 14, 2020 to June 20, 2021, lockdown period and 1 year after lockdown).

Results: We observed a 46.9% decrease in the number of CRC diagnoses (95% confidence interval (CI): 45.1%-48.7%) during the lockdown and 29.7% decrease (95% CI: 28.1%-31.4%) in the year after the lockdown. The proportion of patients diagnosed at stage I significantly decreased during the pandemic (21.7% vs. 19.0%; p = 0.025). Centers that applied universal preprocedure SARS-CoV-2 PCR testing experienced a higher reduction in the number of colonoscopies performed during the pandemic post-lockdown (34.0% reduction; 95% CI: 33.6%-34.4% vs. 13.7; 95% CI: 13.4%-13.9%) and in the number of CRCs diagnosed (34.1% reduction; 95% CI: 31.4%-36.8% vs. 26.7%; 95% CI: 24.6%-28.8%). Curative treatment was received by 87.5% of patients diagnosed with rectal cancer prepandemic and 80.7% of patients during the pandemic post-lockdown period (p = 0.002).

Conclusions: The COVID-19 pandemic has led to a decrease in the number of diagnosed CRC cases and in the proportion of stage I CRC. The reduction in the number of colonoscopies and CRC diagnoses was higher in centers that applied universal SARS-CoV-2 PCR screening before colonoscopy. In addition, the COVID-19 pandemic has affected curative treatment of rectal cancers.

Keywords: COVID-19 pandemic; endoscopy; screening colonoscopy.

FIGURE 1

Monthly incidence of CRC in the prepandemic and pandemic periods.

FIGURE 2

Diagnosis of CRC at different stages before and during the prepandemic and pandemic periods.

FIGURE 3

Diagnosis of the different T stages at different stages before and during the prepandemic and pandemic periods. The number of diagnoses was reduced during lockdown.

FIGURE 4

Effect of the SARS‐Cov‐2 PCR testing policy on the number of colonoscopies and diagnosis of CRC. (A) Percentage reduction in colonoscopies and CRC cases diagnosed during the pandemic post‐lockdown period compared to the prepandemic period in centers applying or not applying universal pre‐procedural SARS‐CoV‐2 PCR testing. (B) Total number of colonoscopies in individual centers with universal pre‐procedural PCR (dotted lines) or without universal pre‐procedural PCR (continuous lines). (C) Number of CRC cases diagnosed in individual centers with universal pre‐procedural PCR (dotted lines) or without universal pre‐procedural PCR (continuous lines).