# Peritoneal reflection involvement as a prognostic factor in rectal cancer. Long-term oncological outcomes from a prospective study

## TL;DR

Peritoneal reflection involvement in rectal cancer is linked to higher recurrence and worse survival, according to a long-term study.

## Contribution

Identifies peritoneal reflection involvement as an independent prognostic factor for rectal cancer outcomes.

## Key findings

- 28.2% of tumors at or above the peritoneal reflection showed peritoneal involvement.
- Peritoneal involvement was associated with higher local recurrence and shorter survival.
- Shepherd’s grade 4 involvement was an independent risk factor for both survival and recurrence.

## Abstract

To assess the relevance of peritoneal reflection involvement in long-term oncological outcomes in patients with rectal cancer.

Prospective observational study from a specialized colorectal unit that included a consecutive series of patients undergoing mesorectal excision for rectal cancer. Peritoneal reflection (PR) involvement was evaluated on pathological examination using Shepherd’s classification. Overall survival (OS), disease-free survival (DFS), and local recurrence (LR) were assessed.

One hundred sixty patients were included in the present analysis. Peritoneal involvement was present in 28.2% of the 85 tumors above or at the level of PR. There were no differences in OS, DFS, or LR according to tumor’s height location. The 5-year OS, DFS, and LR for tumors involving PR were 58.3%, 61.7%, and 30.3%, respectively. Patients with peritoneal involvement had a higher LR rate (p = 0.02) and shorter OS (p = 0.04). Shepherd’s grade 4 peritoneal involvement was an independent risk factor for OS (HR 2.9; 95% CI 1.1–9.5, p = 0.04) and LR (HR 4.2; 95% CI 1.2–16.9, p = 0.04).

After rectal cancer resection, peritoneal involvement is an independent risk factor for local recurrence and poor survival.