Colorectal cancer and COVID-19: Do we need to raise awareness and vigilance?

Abstract

We read with great interest the article by Zhang et al1 regarding the higher risk of coronavirus disease 2019 (COVID-19) in patients with cancer compared with patients without a cancer diagnosis. In their study, gastrointestinal cancer (20 patients; 18.7%) ranked as the second most common cancer diagnosis among a total of 107 patients with cancer who were diagnosed with COVID-19,1 a finding that has been of concern among gastrointestinal surgeons and physicians. The question of why patients with gastrointestinal cancer are more vulnerable, and whether other routes of infection exist in addition to respiratory transmission, should arouse our interest. The coronavirus spike protein helps the virus to enter the target cell through the angiotensin-converting enzyme 2 (ACE2) receptor. The transmembrane serine protease 2 (TMPRSS2) facilitates activation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and increases the chance of the virus entering the target cell.2 The expression of ACE2 and TMPRSS2 in lung epithelium may increase the risk of SARS-CoV-2 infection and the severity of COVID-19.3 Clinical evidence has proven that SARS-CoV-2 uses ACE2 as a viral receptor for entry into the gastrointestinal system,4 and therefore higher levels of gene expression predict a greater chance of infection. High levels of ACE2 and TMPRSS2 were found in the human gastrointestinal tract in addition to the respiratory tract.5 We used Gene Expression Profiling Interactive Analysis (GEPIA), a web-based tool that delivers fast and customized functions based on The Cancer Genome Atlas and Genotype-Tissue Expression (GTEx) Program data,6 to analyze the expression levels of ACE2 and TMPRSS2 proteins in normal intestinal tissues and colorectal cancer samples. It was found that the levels of ACE2 and TMPRSS2 expression in colorectal cancer tissues were statistically higher than those in normal tissues. There was no difference noted with regard to the levels of ACE2 and TMPRSS2 expression in colon and rectal cancer of different clinical stages, indicating that colorectal cancer of all clinical stages may be the undifferentiated target of SARS-CoV-2. Therefore, ACE2 and TMPRSS2 expression levels may be high in both tumor tissues and adjacent normal tissues in these patients. This distribution could further increase the possibility of SARS-CoV-2 invading and infecting patients with colorectal cancer. A recent study of 73 hospitalized patients with COVID-19 demonstrated that the feces of approximately 53.42% of these patients was positive for SARS-CoV-2 RNA. Another analysis from He et al7 suggested that approximately 44% of the community transmission of COVID-19 could have occurred prior to symptom onset in infected patients. During colonoscopy or colorectal cancer surgery, physicians or surgeons may need to prevent aerosol contamination from the creation of laparoscopic pneumoperitoneum, or intestinal secretions and fecal contamination from the disposal of intestinal tract and tumors, even in asymptomatic patients. Therefore, gastrointestinal oncologists should raise awareness and vigilance regarding protection and actively take precautions to reduce the risk of infection from intestinal secretions and feces during and after examinations or surgeries in patients with colorectal cancer. Strict infection control measures should be enforced because gastrointestinal tumor surgery has a high risk of infection. Careful handling of intestinal tissue or tumor specimens should be practiced to reduce the risk of transmission caused by intestinal infection and to prevent nosocomial infections. In addition, regardless of their clinical stage of disease, patients with colorectal cancer may be at high risk of contracting COVID-19 and are the crucial protection targets in epidemic prevention. Although further validation of clinical data is needed, these findings are of practical importance: patients with clinically mild or moderate COVID-19 with a diagnosis of colorectal cancer should be given special attention because of a possible longer course of disease or a higher risk of severe infection probability. No specific funding was disclosed. The authors made no disclosures.