Impact of the COVID‐19 pandemic on colorectal cancer surgery in Japan: Clinical Study Group of Osaka University―A multicenter retrospective study

Abstract Aim Due to the overwhelming spread of SARS‐CoV‐2 and its disruption of the healthcare system, delays and reduced numbers were reported for colorectal cancer screening, colonoscopies, and surgery during the COVID‐19 pandemic. This multicenter retrospective study investigated the still poorly understood impact of the COVID‐19 pandemic on colorectal cancer treatment in Japan. Methods This study was organized by the Clinical Study Group of Osaka University, which comprised 32 major institutions in Osaka. We retrospectively analyzed the number of surgeries and colonoscopies performed and the characteristics of patients who underwent surgery for colorectal cancer between March 2019 and February 2021. We compared data collected before and during the COVID‐19 pandemic. We also assessed the methods used for detecting colorectal cancer, including fecal occult blood test, abdominal symptoms, and anemia. Results The COVID‐19 pandemic caused reductions in the annual numbers of surgeries (3569 vs 3198) and colonoscopies (67 622 vs 58 183) performed in the 2020 fiscal year, compared to the 2019 fiscal year. During the COVID‐19 pandemic, a significantly lower proportion of patients were treated for clinical stages ≤I (24.2% vs 26.9%; P = .011), compared to the proportion treated before the pandemic. Fecal occult blood tests for detecting colorectal cancer were used significantly less frequently during the COVID‐19 pandemic (26.2% vs 29.6%; P = .002). These trends were more significant in larger institutions. Conclusion The COVID‐19 pandemic reduced the number of colonoscopies and surgeries performed for colorectal cancer and hindered the detection of asymptomatic early‐stage cancers, and its impact varied by hospital size.