Neoadjuvant radiotherapy plays an important role in the treatment of locally advanced colorectal cancer. Although radiation therapy is extremely important in reducing the tumor mass, downstaging, and therefore providing conditions for curative surgery, neoadjuvant therapy can increase the risk of perioperative complications, which can lead to slower patient recovery, greater perioperative morbidity, prolonged hospitalization, and increased treatment costs.

The aim of the study is to determine whether there is a difference in the incidence of perioperative complications after radical colorectal cancer surgery between patients who received neoadjuvant radiotherapy and those patients who did not undergo neoadjuvant radiation.

Data is collected from the medical documentation and information system of the Oncology Institute of Vojvodina. Demographic characteristics of patients, comorbidities, length of hospital stay, length of treatment in the intensive care unit, occurrence of complications in the perioperative period, as well as data on neoadjuvant therapy are analyzed. All included patients are of similar general condition, as determined by the CFS (Clinical Frailty Scale). Intraoperative complications are graded using the ClassIntra classification of intraoperative adverse events, and the presence of postoperative adverse events are assessed and classified using the Clavien-Dindo classification of postoperative complications and the HARM (HospitAl stay, Readmission, Mortality rate) score.

Inclusion Criteria:

• Adult patients (over 18 years of age)
• Clinical Frailty Scale 2, 3 or 4 status
• Patients undergoing radical surgical treatment of colorectal cancer

Exclusion Criteria:

• Patients undergoing palliative surgical treatment of colorectal cancer

Patients undergoing elective radical colorectal cancer surgery in the period between 01.06.2024. and 30.06.2026. in the Oncology Institute of Vojvodina.