Adult stem cells have great differentiation plasticity as embryonic stem cells,can differentiate into other cells or tissues,and have been a hot research spot.This article mainly analyzed the occurrence of tumor stem cells,believed that tumor stem cells are the root of tumor growth,invasion,migration and relapsing,discussed stomach stem cells,tried to search the correlation of carcinoma and stomach stem cells,and analyzed that carcinoma may be a kind of stem cell disease.

Objective To investigate the influence of the lymph node micrometastasis and its clinicopathological features on postoperative disease-free survival rate for patients with gastric cancer.Methods The study included 120 patients with pT1-3NoMo gastric cancer. The relationships between clinicopathological features or carcinoembryonic antigen (CEA) positive expression and postoperative disease-free survival rate were analyzed. Results In clinicopathological factors, multivariate analysis identified CEA positive expression was significantly correlated with tumor diameter (P = 0.011 ),depth of tumor invasion (P= 0.027) and lymphatic vessel invasion (P= 0.001 ) in lymph node positively. The average postoperative follow-up was (53.14 ± 16.75) months. There was statistical correlation between the tumor diameter( P = 0.018 ) or depth of tumor invasion ( P = 0.015 ) and postoperative disease-free survival rate. The disease-free survival rate was 90.91% ( 80/88 ), 86.36% ( 19/22 )and 40.00% (4/10) for the lymph node CEA negative,isolated tumor cells (IT Cs) and micrometastasis,respectively. There was significant difference between micrometastasis and the lymph node CEA negative (P= 0.000) or ITCs (P = 0.009), however, the lymph node CEA negative and ITCs was no significant difference (P = 0.438 ). Lymph node micrometastssis of gastric cancer was detected in 10 patients who should belong to stage pN1,the restage rate was 8.33%(10/120). Conclusions If the patients were found micrometastasis in lymph node with high-risk stage pT1-3NoMo gastric cancer for whom chemotherapy may be recommended,because of its high recurrence and poor prognosis.