The Prognostic Significance of an R1 Resection in Gastric Cancer Patients Treated with Adjuvant Chemoradiotherapy

Background. A microscopically irradical (R1) resection is a well-known adverse prognostic factor after gastric cancer surgery. However, the prognostic significance of an R1 resection in gastric cancer patients who are treated with chemoradiotherapy (CRT) after the operation has been poorly studied. Therefore, the aim of this study was to evaluate the effect of an R1 resection on (recurrence-free) survival in gastric cancer patients who were treated with CRT after surgery. Methods. Gastric cancer patients who had undergone a resection with curative intent followed by adjuvant CRT at our institute between 2001 and 2011 were included. CRT consisted of radiotherapy (45 Gy/25 fractions) combined with concurrent capecitabine (with or without cisplatin) or 5-fluorouracil/leucovorin. Results. A consecutive series of 110 patients was studied, including 80 (73 %) patients who had undergone an R0 resection and 30 (27 %) patients with an R1 resection. Pathologic T-classification (p = 0.26), N-classification (p = 0.77), and histologic subtype according to Lauren (p = 0.071) were not significantly different between these groups. Three-year recurrence-free survival (45 vs. 35 %, p = 0.34) and overall survival (47 vs. 48 %, p = 0.58) did not significantly differ between patients who had undergone an R0 or R1 resection. In a multivariate analysis, pathologic T-classification and N-classification were independent prognostic factors for survival. Conclusions. A R1 resection was not an adverse prognostic factor in gastric cancer patients who had undergone CRT after the operation.