Impact of SARS-CoV-2 Pandemic on Colorectal Cancer Screening Delay: Effect on Stage Shift and Increased Mortality

Abstract

Background & aims: The SARS-CoV-2 pandemic had a sudden, dramatic impact on healthcare. In Italy, since the beginning of the pandemic, colorectal cancer (CRC) screening programs have been forcefully suspended. We aimed to evaluate whether screening procedure delays can affect the outcomes of CRC screening.

Methods: We built a procedural model considering delays in the time to colonoscopy and estimating the effect on mortality due to up-stage migration of patients. The number of expected CRC cases was computed by using the data of the Italian screened population. Estimates of the effects of delay to colonoscopy on CRC stage, and of stage on mortality were assessed by a meta-analytic approach.

Results: With a delay of 0-3 months, 74% of CRC is expected to be stage I-II, while with a delay of 4-6 months there would be a 2%-increase for stage I-II and a concomitant decrease for stage III-IV (P = .068). Compared to baseline (0-3 months), moderate (7-12 months) and long (> 12 months) delays would lead to a significant increase in advanced CRC (from 26% to 29% and 33%, respectively; P = .008 and P < .001, respectively). We estimated a significant increase in the total number of deaths (+12.0%) when moving from a 0-3-months to a >12-month delay (P = .005), and a significant change in mortality distribution by stage when comparing the baseline with the >12-months (P < .001).

Conclusions: Screening delays beyond 4-6 months would significantly increase advanced CRC cases, and also mortality if lasting beyond 12 months. Our data highlight the need to reorganize efforts against high-impact diseases such as CRC, considering possible future waves of SARS-CoV-2 or other pandemics.

Keywords: Colon Cancer; Colonoscopy; Colorectal Cancer Screening; Fecal Immunochemical Test; SARS-CoV-2.

Figure 1

Illustrative description of the rationale: SARS-Cov-2 effects on screening programs and consequently on the CRC stage distribution and survival rates. CRC, colorectal cancer; FIT, fecal immunochemical test; SARS-Cov-2, severe acute respiratory distress syndrome–associated coronavirus 2.

Supplementary Figure 1

Flowchart for the delay stage meta-analysis.

Supplementary Figure 2

Flowchart for the stage mortality meta-analysis.

Supplementary Figure 3

Proportion of colorectal cancer by stage (I–II and III–IV) at different delays (0–3 months, 4–6 months, 7–12 months, >12 months). Pooled estimates by delay stage meta-analysis. I² index: 97% (0–3 months), 72.4% (4–6 months), 48.2% (7–12 months), 82.6% (>12 months). CI, confidence interval.

Supplementary Figure 4

Survival rates at 5 years by stage (I–II and III–IV). Pooled estimates by stage mortality meta-analysis. I² index: 99% (stage I–II), 99% (stage III–IV). CI, confidence interval.