BACKGROUND

Patients with colorectal cancer (CRC) are more likely to develop severe course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and experience increased risk of mortality compared to SARS-CoV-2 patients without CRC.

OBJECTIVES

To estimate the prevalence of SARS-CoV-2 infection in CRC patients and analyse the demographic parameters, clinical characteristics and treatment outcomes in CRC patients with COVID-19 illness.

METHODS

For this systematic review and meta-analysis, we searched Proquest, Medline, Embase, Pubmed, CINAHL, Wiley online library, Scopus and Nature for studies on the incidence of SARS-CoV-2 infection in CRC patients, published from December 1, 2019 to December 31, 2021, with English language restriction. Effect sizes of prevalence were pooled with 95% confidence intervals (CIs). Sub-group analyses were performed to minimize heterogeneity. Binary logistic regression model was used to explore the effect of various demographic and clinical characteristics on patient's final treatment outcome (survival or death).

RESULTS

Of the 472 papers that were identified, 69 articles were included in the systematic review and meta-analysis (41 cohort, 16 case-report, 9 case-series, 2 cross-sectional, and 1 case-control studies). Studies involving 3362 CRC patients with confirmed SARS-CoV-2 (all patients were adults) were analyzed. The overall pooled proportions of CRC patients who had laboratory-confirmed community-acquired and hospital-acquired SARS-CoV-2 infections were 8.1% (95% CI 6.1 to 10.1, n = 1308, 24 studies, I 98%, p = 0.66), and 1.5% (95% CI 1.1 to 1.9, n = 472, 27 studies, I 94%, p < 0.01). The median patient age ranged from 51.6 years to 80 years across studies. The majority of the patients were male (n = 2243, 66.7%) and belonged to White (Caucasian) (n = 262, 7.8%), Hispanic (n = 156, 4.6%) and Asian (n = 153, 4.4%) ethnicity. The main source of SARS-CoV-2 infection in CRC patients was community-acquired (n = 2882, 85.7%; p = 0.014). Most of those SARS-CoV-2 patients had stage III CRC (n = 725, 21.6%; p = 0.036) and were treated mainly with surgical resections (n = 304, 9%) and chemotherapies (n = 187, 5.6%), p = 0.008. The odd ratios of death were significantly high in patients with old age (≥ 60 years) (OR 1.96, 95% CI 0.94-0.96; p < 0.001), male gender (OR 1.44, 95% CI 0.41-0.47; p < 0.001) CRC stage III (OR 1.54, 95% CI 0.02-1.05; p = 0.041), CRC stage IV (OR 1.69, 95% CI 0.17-1.2; p = 0.009), recent active treatment with chemotherapies (OR 1.35, 95% CI 0.5-0.66; p = 0.023) or surgical resections (OR 1.4, 95% CI 0.8-0.73; p = 0.016) and admission to ICU (OR 1.88, 95% CI 0.85-1.12; p < 0.001) compared to those who survived.

CONCLUSION

SARS-CoV-2 infection in CRC patient is not uncommon and results in a mortality rate of 26.2%. Key determinants that lead to increased mortality in CRC patients infected with COVID-19 include older age (≥ 60 years old); male gender; Asian and Hispanic ethnicity; if SARS-CoV-2 was acquired from hospital source; advanced CRC (stage III and IV); if patient received chemotherapies or surgical treatment; and if patient was admitted to ICU, ventilated or experienced ARDS.