A case of pathologic complete remission of advanced gastric cancer induced by concurrent chemoradiation with S1 and cisplatin

Although the required extent of lymph node dissection remains controversial, surgery is the cornerstone of the treatment of advanced gastric cancer. However, only approximately 30% of patients are diagnosed as operable, and an R0 resection will be achieved in only 40"`60% of these. Since R0 resection and the treatment response of the primary cancer or resected specimen are significant prognostic factors in locally advanced gastric cancer, various preoperative treatment modalities have been attempted to induce downstaging and improve complete nodal resection. Several recent studies revealed that preoperative chemoradiation therapy can prolong patient survival by improving the R0 resection rate and treatment response. Here, we present an advanced gastric cancer patient with serosal penetration involving multiple perigastric and celiac lymph nodes who underwent radical surgery and entered complete remission after S1 and cisplatin-based concurrent chemoradiation therapy. Pathology revealed total necrosis of the tumor cells, and fibrous nodules in 2 out of 47 resected lymph nodes indicated dead cancer cells due to chemoradiation therapy. Subsequently, the patient received an additional six rounds of postoperative adjuvant chemotherapy with uracil/tegafur (UFT) and cisplatin. Follow-up imaging showed no evidence of tumor recurrenceope