Prognostic impact of microscopic tumor involved resection margin in advanced gastric cancer patients after gastric resection.

Background: The prognosis of patients with positive surgical resection margins is dismal in gastric cancer. However, the influence of positive margin itself on prognosis is still uncertain, especially in advanced gastric cancer (AGC). The aims of the present study were to evaluate the prognostic impact of microscopic tumor involved resection margins in stage III-IV AGC after gastric resection in comparison with other well-known factors.

Methods: Among 1,536 consecutive gastric cancer patients who received intentional curative resection for stage III-IV AGC between April 2001 and December 2011 at the National Cancer Center, 35 patients (2.28 %) had positive resection margins on their final histology. A comparison of clinicopathologic characteristics, recurrence pattern, overall survival (OS), and disease-free survival (DFS) was made between positive margin (PM) patients and negative margin (NM) patients.

Results: Among the 35 PM patients, 15 (42.9 %) had proximal involved margins, 21 (60.0 %) had distal involved margins, and one (2.9 %) had both involved margins. Twenty-eight PM patients (80.0 %) were stage III, and 7 (20.0 %) were stage IV. Recurrence was significantly higher in PM than NM (63.6 % vs. 39.7 %, respectively; p = 0.005). The OS and DFS rates were significantly lower in the PM group than in the NM group (14.9 vs. 36.3 months, p < 0.001 and 11.6 vs. 27.1 months, p = 0.005, respectively). The presence of PM was an independent risk factor for both OS and DFS.

Conclusions: The presence of PM is an independent risk factor for OS and DFS. Considering the prognostic impact of PM, a sufficient resection margin should be ensured when determining the resection line in gastrectomy with curative intent. The reoperation to secure clear resection margins should be considered as a treatment of choice in the case of PM.