title: Common variants in ABCB1, ABCC2 and ABCG2 genes and clinical outcomes among women with advanced stage ovarian cancer treated with platinum and taxane-based chemotherapy: a Gynecologic Oncology Group study.
abstract: OBJECTIVE
  Efflux transporters of the ATP-binding cassette (ABC) family are major determinants of chemoresistance in tumor cells. This study examined associations between functional variants in ABCB1, ABCC2 and ABCG2 genes and clinical outcomes in patients with epithelial ovarian/primary peritoneal cancer (EOC/PPC) following platinum and taxane-based chemotherapy.
  
  
  METHODS
  Sequenom iPLEXTMGOLD Assay and MALDI-TOF platform were used to genotype the non-synonymous G2677T/A (rs2032582; encoding Ala893Ser/Thr) and synonymous C3435T (rs1045642; encoding Ile1145Ile) variants in ABCB1, the non-synonymous G1249A variant in ABCC2 (rs2273697; encoding Val417Ile), and the non-synonymous C421A variant in ABCG2 (rs2231142; encoding Q141K, Gln141Lys) in normal DNA from up to 511 women in Gynecologic Oncology Group (GOG) phase III trials, GOG-172 or GOG-182. Progression-free survival (PFS) and overall survival (OS) were analyzed in relation to genetic polymorphisms using Kaplan-Meier and Cox proportional hazards model.
  
  
  RESULTS
  The C421A variant (CA+AA versus CC) in ABCG2 was associated with a 6-month longer median PFS (22.7 versus 16.8 months, p=0.041). In multivariate analysis, patients with variant genotypes were at a reduced risk of disease progression (hazard ratio [HR]=0.75, 95% confidence interval [CI]=0.59-0.96, p=0.022). The association between C421A and OS was not statistically significant (HR=0.88, 95% CI=0.67-1.15, p=0.356). None of the other variants measured in either ABCB1 or ABCC2 was associated with PFS or OS.
  
  
  CONCLUSIONS
  The C421A variant in ABCG2, previously shown to be associated with enhanced protein degradation and drug sensitivity, was associated with longer PFS in advanced stage EOC/PPC patents treated with platinum+taxane-based chemotherapy. This finding requires further validation.
authors: Gynecologic Oncology Group Statistical and Data Center, Buffalo, NY 14263, USA.
authors: Chunqiao
authors: C
authors: Tian
authors: Christine B
authors: CB
authors: Ambrosone
authors: Kathleen M
authors: KM
authors: Darcy
authors: Thomas C
authors: TC
authors: Krivak
authors: Deborah K
authors: DK
authors: Armstrong
authors: Michael A
authors: MA
authors: Bookman
authors: Warren
authors: W
authors: Davis
authors: Hua
authors: H
authors: Zhao
authors: Kirsten
authors: K
authors: Moysich
authors: Holly
authors: H
authors: Gallion
authors: Julie A
authors: JA
authors: DeLoia
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage; D002945:Cisplatin / Q000008:administration & dosage; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008875:Middle Aged; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D017239:Paclitaxel / Q000008:administration & dosage; D011110:Polymorphism, Genetic; D019772:Topotecan / Q000008:administration & dosage; D055815:Young Adult; D000093542:Gemcitabine
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D016190:Carboplatin; D002945:Cisplatin; D003841:Deoxycytidine; D004317:Doxorubicin; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D017239:Paclitaxel; D019772:Topotecan; D000093542:Gemcitabine; C513055:ABCB1 protein, human; C000715087:ABCC2 protein, human; C116614:ABCG2 protein, human