Oncologic outcomes of colorectal cancer during the coronavirus pandemic: a multicenter retrospective study

Background: The COVID-19 pandemic disrupted global healthcare, delaying colorectal cancer (CRC) treatment and possibly worsening outcomes, thereby emphasizing the need for urgent management strategies. Materials and methods: This observational cohort study involved patients who underwent CRC surgery at eight tertiary care institutions in Korea from 2018 to 2020. The study period was divided into two phases: the pre-COVID-19 period, from January 2018 to February 2020, and the COVID-19 period, from March to December 2020. The main outcomes of the study were stage distribution and recurrence-free survival. The collected data were analyzed to evaluate differences in oncologic outcomes between CRC patients before and during the pandemic. Results: During the COVID-19 period, patients had more advanced disease (stage IV: 13.5% vs. 10.6%, P < 0.001) and more tumor-related complications, including perforation, abscess, or obstruction ( P < 0.001). Open surgery (15.4% vs. 13.8%, P = 0.013) and combined resections (18.1% vs. 15.8%, P = 0.006) were also more frequent. Pathologic stage was more advanced in patients without preoperative treatment ( P = 0.004), whereas ypT and ypN stages were similar in those receiving neoadjuvant therapy. Three-year recurrence-free survival was comparable (88.3% vs. 88.8%), and in multivariable Cox regression, the COVID-19 period was not independently associated with recurrence-free survival ( P = 0.253). Postoperative complications were more common during the pandemic (16.6% vs. 13.6%, P < 0.001), particularly in rectal cancer (20.4% vs. 14.8%, P < 0.001), with higher rates of anastomotic leakage after preoperative chemoradiotherapy ( P = 0.003), but Clavien–Dindo severity did not differ ( P = 0.136). Conclusion: During the COVID-19 pandemic, patients with CRC presented at more advanced stages and with more complications, yet recurrence-free survival was similar. In patients receiving neoadjuvant therapy, the stage distribution was comparable between periods. These findings highlight the need for strategies to prevent disease progression and preserve outcomes in future crises and for studies on long-term outcomes and the continuity of cancer care.