[R1 resection in rectal cancer].

Area of Science:

• Oncology
• Surgical Oncology
• Gastrointestinal Surgery

Background:

• R1 resections in rectal cancer, defined by tumor proximity to the circumferential resection margin (CRM), are associated with higher local recurrence, distant metastases, and poorer prognosis.
• Current guidelines differentiate R0 resections into R0 wide (≥1 mm) and R0 close (<1 mm), highlighting the critical importance of CRM status.

Purpose of the Study:

• To emphasize the decisive role of surgical technique in achieving negative margins (R0) during rectal cancer resection.
• To underscore the necessity of standardized surgical preparation and potential deviation from anatomical planes to ensure complete tumor removal.

Main Methods:

• Standardized radical preparation along boundary layers and envelope fascia.
• En bloc resection of adjacent structures when necessary to achieve negative margins.
• Evaluation of neoadjuvant therapy's role in reducing R1 situations.

Main Results:

• Surgical technique is the primary determinant in avoiding R1 resections.
• Neoadjuvant therapy can reduce R1 situations but cannot overcome inadequate surgical procedures.
• Tumor proximity to the CRM significantly increases risks, necessitating clear margin definitions.

Conclusions:

• Optimal surgical technique is paramount for achieving negative circumferential resection margins (CRM) in rectal cancer.
• While neoadjuvant therapy aids in reducing positive margins, it cannot substitute for meticulous surgical execution.
• Adherence to guidelines differentiating R0 wide, R0 close, and R1 resections is essential for improved rectal cancer management.