Is adjuvant chemotherapy necessary in pT1N1 gastric cancer?

BACKGROUND: Due to a lack of consensus on adjuvant treatments for pT1N1 gastric cancer, surgeons face a dilemma when deciding treatments for patients with pT1N1 gastric cancer after gastrectomy. The objective of this study was to determine survival benefits of adjuvant chemotherapy and risk factors for tumor recurrence in gastric cancer patients with pT1N1. METHODS: Between 1996 and 2010, 510 patients who underwent curative resection for pT1N1 gastric cancer at three institutes were divided into two groups: adjuvant chemotherapy group (N = 150) and surgery-only group (N = 360). Disease-free survival rates and risk factors for tumor recurrence were analyzed. RESULTS: During the median follow-up of 78 months, 7.5% of patients experienced tumor recurrence (7.3% in adjuvant chemotherapy group and 7.5% in surgery-only group). The 5-year disease-free survival rate was 91.8% in the adjuvant chemotherapy group and 94.6% in the surgery-only group without significant difference between the two. In univariate analysis, older age (>65 years), male gender, body mass index <25 kg/m(2), elevated gross type, and differentiated histology were associated with tumor recurrence. Multivariate analysis showed that advanced age and male gender were independent risk factors for tumor recurrence. In addition, adjuvant chemotherapy showed no benefitial effect on tumor recurrence in pT1N1 gastric cancer. CONCLUSIONS: Adjuvant chemotherapy did not show any oncologically benefitial effect on tumor recurrence, it might be unnecessary for pT1N1 gastric cancer after curative surgery.