title: Comparison between better and poorly differentiated locally advanced gastric cancer in preoperative chemotherapy: a retrospective, comparative study at a single tertiary care institute.
abstract: BACKGROUND
  Gastric cancer is the third leading cause of cancer-related mortality in China, and the long-term survival for locally advanced gastric cancer is very poor. Simple surgery cannot yield an ideal result because of the high recurrence rate after tumor resection. Preoperative chemotherapy could help to reduce tumor volume, improve the R0 resection rate (no residual tumor after surgery), and decrease the risk of local tumor recurrence. The aim of this study was to evaluate the influence of pathological differentiation in the effect of preoperative chemotherapy for patients with locally advanced gastric cancer.
  
  
  METHODS
  Patients with locally advanced gastric cancer (n = 32) received preoperative chemotherapy under the XELOX (capecitabine plus oxaliplatin) regimen. According to pathological examination, patients' tumors were classified into better (well and moderate) and poorly differentiated (lower differentiated and undifferentiated) groups, and the clinical response rate, type of gastrectomy, and negative tumor residual rate were compared between the two groups of patients. Morphological changes and toxic reactions were monitored after chemotherapy.
  
  
  RESULTS
  The results showed that the clinical response rate in the better differentiated group was significantly higher than that in the poorly differentiated group (100% versus 25%, P = 0.000). The partial gastrectomy rate in the better differentiated group was significantly higher than that in the poorly differentiated group (87.5% versus 25% P = 0.000). A significant shrinking of tumor and necrosis of tumor tissues caused by chemotherapy could be observed.
  
  
  CONCLUSIONS
  In conclusion, the better differentiated group with locally advanced gastric cancer is suitable for preoperative chemotherapy under the XELOX regimen, and as a result of effective preoperative chemotherapy, much more gastric tissue can be preserved for the better differentiated group.
authors.affiliation: Department of Gastrointestinal Surgery, China-Japan Union Hospital, Jilin University, No, 126, Xiantai Street, Changchun 130033, China. sunlibo0431@sina.com.
authors.forename: Li-Bo
authors.initials: LB
authors.lastname: Sun
authors.forename: Guo-Jie
authors.initials: GJ
authors.lastname: Zhao
authors.forename: Da-Yong
authors.initials: DY
authors.lastname: Ding
authors.forename: Bin
authors.initials: B
authors.lastname: Song
authors.forename: Rui-Zhi
authors.initials: RZ
authors.lastname: Hou
authors.forename: Yong-Chao
authors.initials: YC
authors.lastname: Li
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000069287:Capecitabine; D002454:Cell Differentiation; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D005472:Fluorouracil / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010071:Oxaloacetates; D011300:Preoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D063128:Tertiary Health Care
chemical_list: D010071:Oxaloacetates; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil