Clinical significance of primary tumor score determined by tumor depth and size in patients with resectable gastric cancer

Although postoperative management of gastric cancer is determined by pathological stage based on the tumor-node-metastasis classification, predicting disease recurrence and prognosis in patients undergoing gastrectomy is clinically difficult. We investigated the depth of tumor invasion and tumor size in resected specimens from patients with gastric cancer and assessed the clinical utility of primary tumor score (PTS) calculated by tumor depth and size as a prognostic marker. We classified 247 patients with gastric cancer into three groups based on cut-off values for deeper tumor invasion (pT2-T4) and larger tumor size (≥ 45 mm) as a PTS of 2 (both abnormalities), 1 (one abnormality), or 0 (neither abnormality). PTS correlated significantly with lymph node metastasis, lymphovascular invasion, and stage (P < 0.0001 each). Survival differences among groups based on PTS were significant (P < 0.0001). Multivariate analysis identified PTS alone as an independent prognostic factor (P = 0.0363). PTS derived from primary tumor information alone is a potentially useful marker for predicting tumor progression and prognosis in postoperative patients with gastric cancer.