Association of positive transection margins with gastric cancer survival and local recurrence.

PURPOSE: To examine the association between positive resection margins and survival and local recurrence in patients with gastric cancer undergoing resection with curative intent.
METHODS: Patients who underwent curative intent resection for gastric carcinoma from 1985 to 2010 were identified from a prospectively maintained database. Positive margins were defined as disease present at the line of luminal transection. Clinicopathological features and outcome of patients undergoing gastrectomy with negative and positive margins were compared.
RESULTS: Among 2384 patients undergoing curative intent resection, 108 (4.5 %) had positive margins. Positive margins were associated with higher American Joint Committee on Cancer (AJCC) stage, T stage, N stage, median number of positive nodes, diffuse Lauren type, and poorly differentiated tumors. Treatment of positive margins consisted of: observation (39 %), chemoradiotherapy (26 %), chemotherapy (20 %), repeat resection (10 %), radiotherapy (4 %), and unknown (1 %). Multivariate analysis of the entire cohort demonstrated margin status, T stage, N stage, grade, and perineural invasion to be independent predictors of survival. Margin status was an independent predictor of survival in patients with ≤3 positive nodes or T1-2 disease but was not in patients with >3 positive nodes or T3-4 disease. Local recurrence occurred in 16 % of patients with a positive margin. We identified no factors predictive of local recurrence in patients with positive margins.
CONCLUSIONS: Positive resection margin is associated with advanced AJCC stage and aggressive tumor biology but remains an independent predictor of worse survival. The significance of a positive margin in gastric cancer is confined to patients with nontransmural disease and/or limited nodal involvement.