Microsatellite Instability Is Associated with the Clinicopathologic Features of Gastric Cancer in Sporadic Gastric Cancer Patients

PURPOSE: Replication error is an important mechanism in carcinogenesis. The microsatellite instability (MSI-H) of colorectal cancers is associated with the development of multiple cancers. The influence of MSI-H on the development of multiple gastric cancers in sporadic gastric cancer patients has not been defined. This study was performed to reveal the association between the clinicopathologic features and MSI in sporadic gastric cancers. MATERIALS AND METHODS: Between July 2004 and March 2009, the clinicopathologic characteristics, including MSI status, were evaluated in 128 consecutive patients with sporadic gastric cancers. None of the patients had hereditary non-polyposis colorectal cancer of familial gastric cancer. The markers that were recommended by the NCI to determine the MSI status for colorectal cancers were used. RESULTS: MSI-H cancers were found in 10.9% of the patients (14/128). Synchronous gastric cancers were shown in 4 patients (3.1%). Synchronous cancers were found in 2 of 14 patients with MSI-H gastric cancer (14.3%) and 2 of 114 patients with MSS gastric cancer (1.8%; P=0.059, Fisher's exact test). Among the patients with synchronous cancer 50% (2/4) had MSI-H cancer, but 9.7% of the patients (12/124) without synchronous cancer had MSI-H cancer. MSI-H (RR, 24.7; 95% CI, 1.5~398.9; P=0.024) was related with to synchronous gastric cancer, but age, gender, family history, histologic type, location, gross morphology, size, and stage were not related to synchronous gastric cancer. CONCLUSIONS: MSI is associated with the intestinal-type gastric cancer and the presence of multiple gastric cancers in patients with sporadic gastric cancer. Special attention to the presence of synchronous and the development of metachronous multiple cancer in patients with MSI-H gastric cancer is needed.

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

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 recurrence.