COVID-19 pandemic associated with lower screening participation and higher mortality in colorectal cancer patientsCOVID-19 pandemic caused significant delays and risks for colorectal cancer

Frontiers in Medicine Published August 20, 2026 Study authors: Khaled Bonna, Abdulrahman Alshawaf, Faisal Abusharkh, Meshari Alenazi, Jamil Aljehany, Afaf Bazerbas… DOI ↗ Editorial oversight: Dr. Lars van Dijk, PhD · Surgical, Procedural & Diagnostic

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Key Takeaway

Note that COVID-19 pandemic conditions were associated with lower screening rates and higher mortality in colorectal cancer.

This systematic review evaluates the impact of the COVID-19 pandemic on management strategies, treatment outcomes, and survival rates for adult patients with colorectal cancer. The synthesis identifies significant disruptions in routine screening and diagnostic procedures, noting that CRC screening participation declined by 30-80% and colonoscopy volumes fell by up to 92%.

The review highlights a shift toward more advanced disease presentation, with a higher proportion of patients presenting with Stage IV or locally advanced tumors. Treatment protocols were also affected, characterized by reduced elective surgical volumes and an increased use of neoadjuvant therapy. Furthermore, the data indicates a significantly higher mortality risk during the pandemic, specifically noting that survival was dramatically worse for patients with COVID-19 co-infection.

While specific statistical significance for individual outcomes like stage shifts was not provided, the synthesis identifies a clear trend of disrupted care. These findings suggest that public health crises can lead to significant delays in diagnosis and treatment. The results underscore the need for resilient cancer care systems capable of maintaining essential services during future emergencies.

How this fits prior evidence

This systematic review addresses gaps in understanding how global health crises impact colorectal cancer management. While prior coverage has focused on surgical techniques like TR-LAR, diagnostic tools such as deep learning models, and risk factors like obesity or berberine trials, this evidence highlights the systemic impacts of pandemic-related disruptions on screening volumes and survival rates.

When the COVID-19 pandemic hit, many healthcare systems struggled to keep up. For people fighting colorectal cancer, this meant significant hurdles. The review shows that screening participation dropped by 30% to 80%, while colonoscopy volumes fell by as much as 92%. These gaps in care mean many patients were not caught early enough.

Because of these delays, more patients were diagnosed with advanced stages of the cancer or tumors that had already spread locally. Doctors also had to change how they treated patients, leading to fewer elective surgeries and a higher use of neoadjuvant therapy (treatment given before the main surgery).

The data shows a clear link between the pandemic and worse outcomes. Patients faced a significantly higher risk of death during this time. Specifically, those who caught both COVID-19 and colorectal cancer had much worse survival rates. These findings highlight how vital it is to keep cancer services running even during public health crises.

What this means for you:

The pandemic caused major drops in screenings and led to more advanced cancer diagnoses and higher death rates.

Common questions

How did the pandemic affect cancer screening?

Screening participation for colorectal cancer dropped by 30% to 80% during the pandemic. Additionally, the number of colonoscopies performed fell by up to 92%. These significant drops in routine testing mean many people may have missed early detection.

Did the timing of diagnosis change for patients?

Yes. Because of fewer screenings and delays, a higher proportion of patients were diagnosed with advanced stages of cancer or tumors that were already locally advanced. This means many cases were caught later than they would have been in normal circumstances.

What happened to patients who had both COVID-19 and cancer?

Patients who had a co-infection of both COVID-19 and colorectal cancer saw dramatically worse survival rates. The data shows that having both conditions at once led to much poorer outcomes for the patient.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedAug 2026

View Original Abstract ↓

The COVID-19 pandemic caused a catastrophic disruption to global healthcare systems. For colorectal cancer (CRC), the world’s third most prevalent cancer, the suspension of screening programs and reallocation of resources threatened to severely impact timely diagnosis and treatment, with pre-existing models predicting significant excess mortality from even short delays. This systematic review aimed to assess the impact of the COVID-19 pandemic on the management strategies, treatment outcomes, and survival rates of patients with colorectal cancer. A systematic review was conducted following PRISMA guidelines. A comprehensive search of PubMed was performed for studies published from 2020 onwards. Eligible studies included those focusing on adult CRC patients and reporting on changes in care pathways or outcomes due to the pandemic. Data on diagnostic delays, treatment modifications, stage at presentation, and survival were extracted and synthesized narratively. The synthesis of results from the included studies revealed a cascade of negative consequences. There was a severe global reduction in CRC screening, with participation declining by 30-80% and colonoscopy volumes falling by up to 92%, leading to a pool of “missing” diagnoses. This resulted in a significant stage shift, with a higher proportion of patients presenting with advanced stage (e.g., Stage IV) and locally advanced tumors. Treatment protocols were modified, including reduced elective surgical volumes and increased use of neoadjuvant therapy. Consequently, patients diagnosed during the pandemic faced a significantly higher mortality risk, a trend exacerbated by COVID-19 co-infection, which was associated with dramatically worse survival. The pandemic also exacerbated health disparities and imposed a profound psychosocial burden on patients. The COVID-19 pandemic had a detrimental impact on every facet of colorectal cancer care, from screening and diagnosis to treatment and outcomes, leading to more advanced disease at presentation and worsening survival. These findings underscore the critical need to develop resilient cancer care systems that can maintain essential services during future public health crises. https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42025638100.

COVID-19 pandemic associated with lower screening participation and higher mortality in colorectal cancer patientsCOVID-19 pandemic caused significant delays and risks for colorectal cancer

How this fits prior evidence

Common questions

Study Details

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COVID-19 pandemic associated with lower screening participation and higher mortality in colorectal cancer patientsCOVID-19 pandemic caused significant delays and risks for colorectal cancer

How this fits prior evidence

Common questions

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