title: Significance of multidrug resistance gene-related proteins in the postoperative chemotherapy of gastric cancer.
abstract: BACKGROUND
  Multidrug resistance (MDR) is a serious problem in chemotherapy and is one of the main reasons for a poor outcome of gastric cancer. Study on the key proteins in multidrug resistance is necessary for the treatment of gastric cancer.
  
  
  METHODS
  The expression of ToPo II, MRP and GST-π in 119 gastric cancers was retrospectively examined, and the results were analyzed in correlation with clinicopathological data. ToPo II negative, MRP positive and GST-π positive were regarded as three risk factors which may be associated with chemotherapy resistance and poor prognosis. Patients were divided into two groups: high-risk group (≥2 risk factors) and the low-risk group (<2 risk factors), and the tumor recurrence and patients' survival time of the two groups were also analyzed.
  
  
  RESULTS
  The positive rates of ToPo II, MRP and GST-π were 73.9%, 42.9% and 51.3%, respectively. The positively correlation between the expression of MRP and GST-π had been found. A significant correlation was shown between ToPo II expression and the level of differentiation. Significant differences with GST-π expression were also found in relation to the sex and differentiation. In the high-risk group, the 3-year survival rate of patients with/without chemotherapy were 62.1% and 52.0%, 5-year survival rates were 44.8% and 40.0%, but the difference was not statistically significant (P>0.05). In the low-risk group, the 3-year survival rate of patients with/without chemotherapy were 81.2% and 51.5%, 5-year survival rates were 71.9% and 45.5%, and the difference was statistically significant (P<0.05).
  
  
  CONCLUSIONS
  Combined detection of MDR-related proteins ToPo II, MRP and GST-π may be prospectively valuable for postoperative individualized chemotherapy, and further predict the outcomes of gastric cancer patients.
authors.affiliation: Department of Hepatobilliary and Pancreatic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China; Department of Abdominal Surgery, Zhejiang Cancer Hospital, Hangzhou 310022, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Yu
authors.affiliation: Department of Abdominal Surgery, Zhejiang Cancer Hospital Hangzhou 310022, China.
authors.forename: Yian
authors.initials: Y
authors.lastname: Du
authors.affiliation: Department of Abdominal Surgery, Zhejiang Cancer Hospital Hangzhou 310022, China.
authors.forename: Litao
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Abdominal Surgery, Zhejiang Cancer Hospital Hangzhou 310022, China.
authors.forename: Sunfu
authors.initials: S
authors.lastname: Fan
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University Hangzhou 310003, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University Hangzhou 310003, China.
authors.forename: Shusen
authors.initials: S
authors.lastname: Zheng
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D051549:Glutathione S-Transferase pi / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D015996:Survival Rate
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D051549:Glutathione S-Transferase pi; D004250:DNA Topoisomerases, Type II
keywords: Stomach neoplasms; chemotherapy; multidrug resistance-associated proteins; prognosis