Impact of the COVID-19 Pandemic on Colorectal Cancer Diagnosis and Treatment: a Systematic Review

Background Following the official announcement of the COVID-19 pandemic by the World Health Organization (WHO) in March 2020 and decreased activity of healthcare systems, relocation of resources, and the possible reluctance of patients to seek medical help, colorectal cancer patients were exposed to significant risks. Given that colon cancer is the third most common cancer and the second deadliest cancer in the world, its timely diagnosis and treatment are necessary to reduce costs and improve quality of life and patient survival. The aim of this study was to investigate the effects of COVID-19 pandemic on the diagnosis and treatment of colorectal cancer. Methods and Materials A comprehensive search performed on June 2021 in various databases, including Medline, Web of Science, and Scopus. Keywords such as "diagnosis," "treatment," "coronavirus disease-19," "COVID-19," "coronavirus disease," "SARS-CoV-2 infection," "SARS-CoV-2," "2019-nCoV," "coronavirus, 2019 novel," "SARS-CoV-2 virus," severe acute respiratory syndrome coronavirus 2," "COVID-19," "COVID-19, coronavirus disease 19," "SARS coronavirus 2," "colorectal neoplasm," and "colorectal cancer " was used individually or a combination of these words. All retrieved articles were entered into a database on EndNote X7. Then, studies were first selected by title and then by abstract, and at the end, full texts were investigated. Results Of the 850 studies, 43 were identified as eligible. According to studies, the diagnosis of colorectal cancer and the number of diagnostic procedures have decreased. Emergency visits due to obstruction or perforation of the large intestine or in advanced stages of cancer have increased, and a delay in the diagnosis of colorectal cancer has reported from 5.4 to 26%. Treatment of colorectal cancer has also decreased significantly or has been delayed, interrupted, or stopped. This reduction and delay have been observed in all treatments, including surgery, chemotherapy, and long-term radiation therapy; only cases of emergency surgery and short-term radiotherapy has increased. The waiting time for hospitalization and the length of hospital stay after surgery has been reported to be higher. Changes in patients' treatment plans and complete to partial cessation of hospitals activities-that provided treatment services-were reported. Conclusion According to the reduction in the diagnosis and treatment of colorectal cancer due to the COVID-19 pandemic, compensating for the reduction and preventing the continuation of this declining trend, requires serious and effective interventions to prevent its subsequent consequences, including referrals of people with advanced stages and emergency conditions, increasing treatment costs and reducing the quality of life and patients survival.