Postoperative adjuvant chemotherapy is effective in gastric cancer with serosal invasion: Significance in patients chosen for multivariate analysis

Abstract

There are few reports on overall usefulness of adjuvant chemotherapy in gastric cancer patients. We tried to clarify, using multivariate analysis, usefulness of postoperative adjuvant oral chemotherapy in advanced gastric cancer patients after curative resection. Four hundred and eighty-two gastric cancer patients enrolled in a randomized controlled trial were classified into 2 groups based on postoperative chemotherapeutic regimen: oral doxifluridine (5'-DFUR, an intermediate metabolite of capecitabine) (n=245) or oral 5-fluorouracil (5-FU) (n=237). The significant prognostic factors in patients with serosal invasion were chemotherapeutics (5'-DFUR vs. 5-FU) (risk ratio 1.649; 95% CI, 1.112-2.437), lymph node metastasis (no vs. yes) (2.823; 1.422-5.604), and tumor differentiation (differentiated vs. undifferentiated) (1.727; 1.068-2.791). Significant factors influencing peritoneal recurrence time were chemotherapeutics (1.756; 1.063-2.902), serosal invasion (no vs. yes) (2.237; 1.264-3.961), lymph node metastasis (2.541; 1.267-5.095), tumor differentiation (2.656; 1.374-5.136), and tumor location (others vs. total) (3.595; 2.006-6.443). There were no differences in the overall survival between chemotherapy. However, 5'-DFUR produced a better survival time of patients with serosal invasion than 5-FU, that might be attributed to the prevention of peritoneal recurrence in this subset.