Trends in Treatment of Colorectal Cancer and Short-term Outcomes During the First Wave of the COVID-19 Pandemic in Sweden.

Importance: The COVID-19 pandemic has had a large impact on health care systems, not least the treatment of malignant diseases, including colorectal cancer. Objective: To investigate the treatment of colorectal cancer and short-term outcomes during the first wave of the COVID-19 pandemic, compared with the year before. Design, Setting, and Participants: This register-based cohort study used information from the Swedish Colorectal Cancer Registry during the years 2020 and 2019. Patients were from the Stockholm-Gotland region, 1 of 6 health care regions in Sweden, with approximately one-fifth of the country's population and 8 hospitals. All patients with a diagnosis of colorectal cancer from March 1 to August 31, 2019, and March 1 to August 31, 2020, were eligible. Data were analyzed from May to June 2021. Exposures: Diagnosis of colorectal cancer during the peak of the COVID-19 pandemic in 2020. Main Outcomes and Measures: The study aimed to compare the number of patients, time to surgery, operation methods, short-term complications, and residents' involvement in surgical practice between 2019 and 2020. Subanalyses were conducted for colon and rectal cancer. Results: A total of 1140 patients (583 men [51%]; median [IQR] age, 74 [26-99] years in 2019 and 73 [24-96] years in 2020) were enrolled. Fewer patients received a diagnosis of colorectal cancer in March through August 2020 compared with the same months in 2019 (550 vs 590 patients). Overall, patient characteristics were similar, but pretherapeutic tumor stage was more advanced in 2020 compared with 2019, with an increased proportion of T4 tumors (30% [172 patients] vs 22% [132 patients]; χ23 = 21.1; P < .001). The proportion of patients undergoing laparoscopic surgery, time to surgery, and 30-day complications were similar, but the proportion of patients treated with ostomy almost doubled between 2019 and 2020, from 17% (53 patients) to 30% (96 patients) (absolute risk, 13.0%; 95% CI, 6.8% to 20.0%). Residents participated in fewer resections in 2020 than in 2019 (35% [108 patients] vs 27% [83 patients]; absolute risk, -7.90%; 95% CI, -15.00% to -0.55%). On the other hand, the treatment and outcomes for rectal cancer were comparable between the years. Significantly more patients were transferred to the nonemergency, COVID-free hospital in the region in 2020. Conclusions and Relevance: In this Swedish register-based cohort study of patients who received a diagnosis of colorectal cancer during the most intense period of the COVID-19 pandemic, a significant increase in ostomy formation for patients with colon cancer and a lower participation of residents during surgery were observed. These changes most likely were aimed at reducing complications and intensive care unit care.