The COVID-19 pandemic and clinical characteristics of colorectal cancer: a multicenter retrospective study.

The spread of COVID-19 has led to numerous hospitals prioritizing case management and to delays in diagnosis and treatment. Consequently, many cancer patients have developed life-threatening complications during the COVID-19 pandemic. The aim of this study was to investigate the impact of COVID-19 pandemic on colorectal cancer (CRC), including its clinical and pathologic characteristics. This multicenter cohort study was performed at six institutions in Korea and included a total of 3871 patients with CRC treated between March 2019 and February 2021. After exclusion of 211 patients who did not undergo surgery, the data of 3660 patients were compared 1 year before and after the COVID-19 pandemic. The patients' baseline characteristics, CRC-related complications, perioperative outcomes including emergency surgery, R0 resection rates, stoma formations, postoperative complications, and pathologic outcomes were assessed. The number of patients decreased during the pandemic (- 18.0%, from 2127 to 1744), but the baseline characteristics did not differ. The pandemic group had greater disease severity given the presence of bleeding, perforation, and obstruction as complications (9.8% vs. 12.7%, P = 0.033). The proportion of patients who had open surgery (15.9% vs. 17.6%, P = 0.049), stoma formation (11.9% vs. 15.4%, P < 0.001), early postoperative complications (13.5% vs. 17.5%, P = 0.001), and adjuvant chemotherapy increased in the pandemic group (45.5% vs. 50.1%, P = 0.003). The clinical and pathologic features of CRC partly worsened during the pandemic. Healthcare providers and governments should prepare to encounter patients with CRC having poor clinical features for years and encourage people to participate in cancer screening programs. The Clinical Research Information Service (No. KCT0008063), January 2, 2023, retrospectively registered.