Colorectal cancer frequently presents with liver metastases, and complete removal of both primary and liver tumors can significantly improve survival. Simultaneous resection (SA) of the colon and liver is increasingly used and is considered safe when minor liver resections are performed, offering advantages such as shorter hospitalization, fewer complications, and faster chemotherapy initiation.

However, the best sequence of resection, liver-first or colon-first, remains uncertain, as each has potential benefits and drawbacks, particularly regarding anastomotic healing. Minimally invasive approaches to SA show similar outcomes to open surgery, though limited data suggest that resection order may affect blood loss.

Colorectal cancer is the third most common cancer worldwide, and 15-25% of patients present with liver metastases at diagnosis. Complete resection of both the primary tumor and liver metastases can yield survival rates up to 47.9%. Simultaneous resection (SA) of the colon and liver is a potential option for patients with synchronous metastases, though traditionally considered high-risk, especially when major hepatectomies are involved.

Recent studies show that SA is safe when minor hepatectomies are paired with standard colon resections and may offer advantages such as reduced hospital stay, lower costs, fewer complications, and faster initiation of chemotherapy.

The optimal sequence of resection in SA remains unclear. Liver-first procedures may preserve sterility and address the prognostically significant lesion first but could impair bowel anastomosis healing.

Minimally invasive surgery (MIS), including laparoscopic and robotic approaches, is increasingly used for SA and appears comparable to open surgery in terms of morbidity, mortality, and oncologic outcomes. Early data on MIS suggest that resection order may influence intraoperative blood loss, but findings remain inconsistent and require further investigation.

Inclusion Criteria:

• Adult patients diagnosed with colorectal cancer with synchronous liver metastases during the reference period, who underwent simultaneous resection.

Exclusion Criteria:

• Simultaneous emergency resection due to symptoms of the primary tumor.
• Presence of extrahepatic metastatic disease confirmed at the time of resection or diagnosis.
• High surgical risk defined as an ASA risk score greater than 3.
• At least 10 cases performed by the invited center during the study period.
• Incomplete data or follow-up of less than 6 months.

Patients undergoing simultaneous treatment of colorectal cancer and liver metastases using open, laparoscopic, and robotic surgery between 2015 and 2023 in participating centers