A case of gastric cancer showing response to first-line XP regimen after lymph node recurrence during the administration of S-1 as postoperative adjuvant chemotherapy

We report on a patient who underwent total gastrectomy with D2 lymph node dissection for metastatic gastric cancer. We administered S-1 at 60 mg/m² as postoperative adjuvant chemotherapy. Six months after surgery, recurrence was detected in the para-aortic lymph node. As a first-line treatment for the recurrent cancer, the patient underwent capecitabine/CDDP therapy(capecitabine 1,800 mg/m², CDDP 60 mg/m²). A significant reduction in the recurrent lymph nodes was observed by CT after 6 months of administration, resulting in 24 months of progression-free survival. S-1/CDDP therapy is recommended as a first-line chemotherapy for recurrent gastric carcinoma in the Japanese gastric cancer treatment guidelines. Likewise, single agent S-1 administration is recommended as postoperative adjuvant chemotherapy for advanced gastric cancer patients. However, in cases of recurrence after S-1 therapy, there is insufficient evidence on the efficacy of S-1/CDDP; thus, the type of administration and time to recurrence could be considered for optimization. We identified a case of gastric cancer showing response to first-line capecitabine/CDDP therapy after lymph node recurrence following the administration of S-1 as postoperative adjuvant chemotherapy. Since capecitabine and S-1 differ in their mechanisms of action and as predictive factors for therapeutic effect, capecitabine may be an efficient option in cases of S-1 failure. The present case suggests that capecitabine/CDDP therapy may be an effective treatment for S-1 pretreated patients with advanced or metastatic gastric cancer.