Differences in risk factors between patterns of recurrence in patients after curative resection for advanced gastric carcinoma

BACKGROUND Recurrence patterns in patients who have undergone curative gastrectomy for advanced gastric carcinoma can be classified as peritoneal, hematogenous, or lymphatic. The aim of this study was to clarify differences in risk factors between these different types of recurrence pattern. METHODS Postoperative courses, including sites of recurrence and periods between surgery and recurrence, of patients who had undergone curative gastrectomy for advanced gastric carcinoma (more than pT2 invasion) were surveyed in detail. Clinicopathological factors were examined as potential independent risk factors for each recurrence pattern, based on recurrence-free survival, using multivariate analysis. RESULTS Multivariate analysis identified depth of tumor invasion (pT4 vs. pT2/3; hazard ratio (HR), 7.05; P < 0.001), number of lymph node metastases (pN2/3 vs. pN0/1; HR, 4.02; P = 0.001), and histological differentiation (G3/4 vs. G1/2; HR, 2.22; P = 0.041) as independent risk factors for peritoneal metastasis. The number of lymph node metastases (HR, 26.21; P < 0.001) and venous vessel invasion (HR, 5.09; P = 0.001) were identified as independent risk factors for hematogenous metastasis. The number of lymph node metastases (HR, 6.00; P = 0.007) and depth of tumor invasion (HR, 4.70; P = 0.023) were identified as independent risk factors for lymphatic metastasis. CONCLUSIONS This study clarified differences in risk factors between various patterns of recurrence. Careful examination of risk factors could help prevent oversight of recurrences and improve detection of recurrences during follow-up. The number of lymph node metastases represents an independent risk factor for all three patterns of recurrence; thus, patients with multiple lymph node metastases warrant particular attention.