Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been identified as the cause of the Coronavirus disease 19 (COVID-19), which was initially reported in December 2019 in China and has since rapidly spread worldwide.

Since then, the COVID-19 pandemic has caused a detrimental effect of the national health care system, causing a drastic reduction of the screening programs for colorectal cancer and requiring the redistribution of the hospital resources from elective surgery to the care of patients with SARS-Cov_2 infection requiring admission.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been identified as the cause of the Coronavirus disease 19 (COVID-19), which was initially reported in December 2019 in China and has since rapidly spread worldwide. Italy witnessed a rapid and uncontrolled spread of the infection after March 2020, and a worrisome increasing number of related deaths.

The need for increased capacity for COVID-19 patients required elective activities to be drastically reduced or canceled. The unprecedented stress on the healthcare system has caused the reduction of the elective surgery and the cancer screening programs during the last 2 years. Studies predicting harmful impact of the COVID-19 pandemic on cancer care have been already published. However, it has not been proved whether the potential delay of screening, diagnosis and treatment could have a measurable effect on patients undergoing surgery for colorectal cancer in the COVID-19 era.

The aim of the study is therefore to compare the 30-day perioperative and oncologic outcomes between patients undergoing surgery for cancer of the colon and rectum between January 2020 and December 2021 (study group) and those who had surgery for colorectal cancer between January 2018 and December 2019 (Control Group), in order to identify:

• any change in the distribution of the histological stage (primary aim)
• any change in the rate of palliative surgery (primary aim)
• any change in the rate of non-radical surgery (R1 or R2 resection) ( primary aim)
• any change in the rate of 30-day postoperative complications (secondary outcome)

Anonimyzed data will be retrospectively collected on a RedCap platform hosted on the servers of the Alma Mater Studiorum University of Bologna. The variables included demographic characteristics, comorbidities, details of the disease at the diagnosis, details of the neoadjuvant therapy, perioperative variables and 30-day postoperative follow-up variables.

Inclusion Criteria:

• Any patient undergoing radical surgery for histologically confirmed diagnosis of cancer located in the colon, the rectum or the anus; or
• any patient undergoing surgery with oncologic intents, for instance: radicalization of endoscopically removed cancerous polyp; radical surgery to remove large, at-risk polyp which are not removable by endoscopy; or
• any patient undergoing planned or unpredicted palliative surgery for a primary cancer localized in the colon, rectum or anus; or
• any patient undergoing a staging procedure (i.e. staging laparoscopy, surgical exploration), which did not result in any radical surgery due to advanced disease, metastasis, etc.

and

• age > 18 years
• elective or urgent surgery

Exclusion Criteria:

• Colorectal cancer recurring after previous surgery;
• Cancer originating from other organs than the colon, the rectum and the anus;
• Lack of significant histological details (expect when the cancer was not removed)
• lack of 30-day follow-up

The study will include all adult patients undergoing elective or urgent surgery for proven or suspected colorectal within the study periods