<strong>Abstract</strong> <em>Introduction:</em> Since its first strike in 2019, the highly contagious Sars-Cov-2 virus has not only directly caused millions of deaths in Vietnam but also indirectly affected many other diseases such as colorectal cancer. In order to clarify this statement, this study was conducted to investigate the difference in disease stage, curative rate of colorectal cancer before and after the Covid-19 outbreak. <em>Patients and Methods:</em> A retrospective study was conducted at Univercity Medical Center, Ho Chi Minh city. Data on cancer stage, surgical methods, and rate of preoperative and postoperative complications were collected from patients treated at the hospital in two stages: group A including patients from February to April 2021 (before applying social distancing) and group B including patients from September to November 2011 (when applying social distancing). <em>Results: </em>When comparing 201 patients in group A and 150 patients in group B, the results showed that the clinical characteristics of the two groups were identical. However, the percentage of cancer that had metastasized at the time of diagnosis was significantly higher in group B than in group A (32% vs 21.4%, p = 0.025), leading to a decrease of radical cure rate in group B (44.7% versus 69.1%, p < 0.001). Particularly for rectal cancer, the rate of advanced tumors (stage T3 CRM+ or T4) in group B was higher than in group A (77.2% vs 58.1%, p = 0.026). <em>Conclusion:</em> In general, not only directly threatening peoples health, the Covid-19 pandemic also delayed the diagnosis of colorectal cancer due to the influence of distancing regulation and the patient's psychological fear, thereby affecting patients prognosis. <em>Keywords:</em> Covid-19, Sars-Cov-2 virus, colorectal cancer, advanced stage cancer. <strong> </strong> <strong>References</strong> <ol> <li>WHO Coronavirus (COVID-19) Dashboard. https://covid19.who.int</li> <li>Bilotta C, Perrone G, Adelfio V, et al. COVID-19 Vaccine-Related Thrombosis: A Systematic Review and Exploratory Analysis. Front Immunol. 2021;12:729251. doi:10.3389/fimmu.2021.729251</li> <li>Morris EJA, Goldacre R, Spata E, et al. Impact of the COVID-19 pandemic on the detection and management of colorectal cancer in England: a population-based study. Lancet Gastroenterol Hepatol. Mar 2021;6(3):199-208. doi:10.1016/s2468-1253(21)00005-4</li> <li>Mazidimoradi A, Hadavandsiri F, Momenimovahed Z, Salehiniya H. Impact of the COVID-19 Pandemic on Colorectal Cancer Diagnosis and Treatment: a Systematic Review. Journal of Gastrointestinal Cancer. 2021/11/29 2021;doi:10.1007/s12029-021-00752-5</li> <li>Abdellatif M, Salama Y, Alhammali T, Eltweri AM. Impact of COVID-19 on colorectal cancer early diagnosis pathway: retrospective cohort study. British Journal of Surgery. 2021;108(4):e146-e147. doi:10.1093/bjs/znaa122</li> <li>De Vincentiis L, Carr RA, Mariani MP, Ferrara G. Cancer diagnostic rates during the 2020 'lockdown', due to COVID-19 pandemic, compared with the 2018-2019: an audit study from cellular pathology. J Clin Pathol. Mar 2021;74(3):187-189. doi:10.1136/jclinpath-2020-206833</li> <li>London JW, Fazio-Eynullayeva E, Palchuk MB, Sankey P, McNair C. Effects of the COVID-19 Pandemic on Cancer-Related Patient Encounters. JCO Clin Cancer Inform. Jul 2020;4:657-665. doi:10.1200/cci.20.00068</li> <li>Brito M, Laranjo A, Sabino J, Oliveira C, Mocanu I, Fonseca J. Digestive Oncology in the COVID-19 Pandemic Era. GE Port J Gastroenterol. Mar 22 2021;579(5):1-8. doi:10.1159/000514784</li> <li>Ferrara G, De Vincentiis L, Ambrosini-Spaltro A, et al. Cancer Diagnostic Delay in Northern and Central Italy During the 2020 Lockdown Due to the Coronavirus Disease 2019 Pandemic. Am J Clin Pathol. Jan 4 2021;155(1):64-68. doi:10.1093/ajcp/aqaa177</li> <li>Lui TKL, Leung K, Guo CG, Tsui VWM, Wu JT, Leung WK. Impacts of the Coronavirus 2019 Pandemic on Gastrointestinal Endoscopy Volume and Diagnosis of Gastric and Colorectal Cancers: A Population-Based Study. Gastroenterology. Sep 2020;159(3):1164-1166.e3. doi:10.1053/j.gastro.2020.05.037</li> <li>Shinkwin M, Silva L, Vogel I, et al. COVID-19 and the emergency presentation of colorectal cancer. Colorectal Dis. Aug 2021;23(8):2014-2019. doi:10.1111/codi.15662</li> <li>Suaùrez J, Mata E, Guerra A, et al. Impact of the COVID-19 pandemic during Spain's state of emergency on the diagnosis of colorectal cancer. J Surg Oncol. Jan 2021;123(1):32-36. doi:10.1002/jso.26263</li> <li>Mizuno R, Ganeko R, Takeuchi G, et al. The number of obstructive colorectal cancers in Japan has increased during the COVID-19 pandemic: A retrospective single-center cohort study. Ann Med Surg (Lond). Dec 2020;60:675-679. doi:10.1016/j.amsu.2020.11.087</li> </ol> <!--more--> <a href="https://vjsel.com/wp-content/uploads/2023/01/BAI-11.pdf">Download PDF File</a>