S-1 is a kind of fouth-generation oral fluoropyrimidine,including tegafur(FT),5-chloro-2,4-dihydroxypyridine(CDHP),and potassium oxonate(Oxo).S-1 is now used in 80% advanced gastric cancer patients in Japan,it's reported that CR+RR is over 44.6%.Neoadjuvant chemotherapy can reduce tumor loading,degrade the staging,afford operation possibility.S-1 combined with CDDP as a new neoadjuvant chemotherapy,is the most efficient therapy in advanced gastric cancer at present,it's CR can be over 76%.

Objective To investigate the micrometastases of No 13 lymph node in gastric carcinoma. Methods In this study, the expression of CK20mRNA, a specific tumor marker of gastric carcinoma, was detected by RQ-PCR for No. 13 group lymph node micrometastasis in 44 gastric carcinoma patients undergoing D2 radical gastrectomy plus No 13 lymph node dissection. Patient's survival was compared with those of 49 gastric cancer eases receiving standard D2 gastrectomy. Results No 13 lymph node micmmetastasis was detected in 11 out of the 44 gastric cancer cases (25%). Micrometastasis was correlated with tumor histological type (P < 0.01) such as mucoid adenocarcinoma and ring cell carcinoma, but not with age, sex, tumor location, tumor size, Bonnann type, depth of invasion (P > 0.05). Group No13 lymph node micrometastasis was detected in 2 out of 6 cases with positive No[2 lymph nodes and in 4 out of 11 cases with positive No14 lymph nodes, the differences were significant with P <0.01, and P < 0.01 respectively, when compared with those with negative No12 lymph nodes and No14 lymph nodes. After a respective median 448 and 419 days follow-up, no obstructive jaundice caused by No 13 lymph node metastasis was detected after No 13 lymph node dissection in radical gastrectomy for gastric carcinoma and such obstructive jaundice was found in one case in the control group. However, there was no significant difference in tumor recurrence between the two groups (Log Rank x2 = 0.426, P = 0.514). Conclusions Dissection of No 13 lymph node in D2 gastrectomy for gastric carcinoma is recommended in patients with poor-differentiation adenocarcinoma, mucous-cell cancer and signet-ring cell cancer, or when No 12 and No 14 lymph node metastasis is suspected.