BACKGROUND

Limited studies exist comparing clinical outcomes by adjuvant treatment for pT1N1 gastric cancer. This study compared the disease-free survival (DFS) of patients with pT1N1 gastric cancer according to the type of adjuvant treatment-surgery alone, chemotherapy (CTx), and chemoradiotherapy (CCRTx)-and evaluated risk factors for tumor recurrence.

METHODS

Between 1995 and 2015, 738 patients underwent radical gastrectomy for pT1N1 gastric cancer and were divided into three groups: surgery alone (n = 355), CTx (n = 214), and CCRTx (n = 169). Chronological changes in adjuvant treatment type and chemotherapeutic regimens were evaluated and DFS was compared. Risk factors for tumor recurrence were analyzed.

RESULTS

The proportion of patients who underwent surgery alone was more than 50% until 2001, and the proportion of those who had either CTx or CCRTx was more than 50% from 2002 to 2011, after which the proportion who underwent surgery alone increased again. The main chemotherapeutic agent was 5-fluorouracil with leucovorin. The 5-year DFS was 96.5% in the surgery-alone group, 96.0% in the CTx group, and 95.8% in the CCRTx group (no significant difference). The various chemotherapeutic regimens did not show differences in DFS. In univariate and multivariate analyses, adjuvant CTx and CCRTx showed no beneficial effect with regard to tumor recurrence.

CONCLUSIONS

Because adjuvant CTx and CCRTx did not show any benefit with regard to tumor recurrence, these treatment strategies might be unnecessary for pT1N1 gastric cancer after gastrectomy. Further studies are necessary to reveal pT1N1 gastric cancer patient subgroups who might benefit from adjuvant treatments.