Impact of self-expandable metallic prosthesis on lymph node dissemination in obstructive left-sided colorectal cancer

The introduction of self-expandable metal stent (SEMS) insertion in obstructive colorectal cancer (CRC) has been associated with an increased risk of tumor perforation, potentially leading to peritoneal dissemination, tumor cell spread via lymphatic vessels, perineural invasion, and peripheral bloodstream. The objective of this study was to assess the impact of SEMS placement on CRC lymph node metastasis.

We retrospectively reviewed 48 patients with malignant colorectal obstruction treated with a temporary SEMS before elective surgery, and 51 patients with malignant colorectal obstruction who underwent elective surgery without prior SEMS placement.

No significant differences were found in the lymph node ratio (LNR) or in the results obtained from the logarithm of the ratio between positive and negative nodes (LODDS). Regarding recurrence, patients without SEMS had a fourfold higher risk of local recurrence compared to those with SEMS (19.6% vs. 6.3%), and a twofold higher risk of distant recurrence (31.4% vs. 14.6%). These differences were statistically significant for overall recurrence and for each local and distant recurrence individually (P = 0.02, P = 0.05, and P = 0.04, respectively).

SEMS placement in obstructive CRC not only shows the potential to suppress tumor growth, but also reduce nodal spread, as no differences in LNR and LODDS values were observed when comparing preoperative SEMS placement in patients with advanced left CRC.