title: Can the analysis of ERCC1 expression contribute to individualized therapy in nasopharyngeal carcinoma?
abstract: OBJECTIVE
  To analyze the expression of excision repair cross-complementation group 1 (ERCC1) protein in predicting the clinical outcome of nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  The histologic specimens of 258 patients with Stage III to IVB nonkeratinizing NPC who were treated with radiotherapy alone (Group I) or concurrent-adjuvant chemoradiotherapy (Group II) were retrieved. Immunostaining on ERCC1 protein was performed. The relationship of ERCC1 expression and clinical outcomes was analyzed.
  
  
  RESULTS
  The median ERCC1 score (proportion score of positively stained cells times intensity) was 200 (range, 0-300), and ERCC1 expression was defined as high if the score was above the median. In Group I high-score tumor had a statistically lower locoregional failure-free rate (LRFFR) compared with low-score tumor (p < 0.05) but not distant failure-free rate (DFFR) and overall survival (OS). In Group II no statistically differences were noted in LRFFR, DFFR and OS with regard to the ERCC1 expression. Resistance to cisplatin-containing chemotherapy in high-ERCC1 score tumor was not observed in Group II. Interestingly, low-score tumor in Group I achieved similar local and distant control compared with Group II. Multivariate analysis showed that ERCC1 score was an independent prognostic factor in LRFFR (p < 0.05) and approached statistical significance in failure-free survival (p = 0.08) and OS (p = 0.07). Tumor with high ERCC1 score had a 2-fold (95% confidence interval, 1.02-3.85) increased risk of locoregional failure. This may imply an association of ERCC1 expression with the repair of radiation damage.
  
  
  CONCLUSIONS
  High ERCC1 expression predicts poor locoregional control in NPC. Chemotherapy response is not affected by ERCC1 expression. Further validation is required.
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong. chansh2@ha.org.hk
authors.forename: Siu Hong
authors.initials: SH
authors.lastname: Chan
authors.forename: Florence M F
authors.initials: FM
authors.lastname: Cheung
authors.forename: Wai Tong
authors.initials: WT
authors.lastname: Ng
authors.forename: Cheuk Wai
authors.initials: CW
authors.lastname: Choi
authors.forename: Kin Nam
authors.initials: KN
authors.lastname: Cheung
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Yiu
authors.forename: Anne W M
authors.initials: AW
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002277:Carcinoma; D002945:Cisplatin / Q000627:therapeutic use; D004268:DNA-Binding Proteins / Q000032:analysis*; D019008:Drug Resistance, Neoplasm; D004720:Endonucleases / Q000032:analysis*; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D009363:Neoplasm Proteins / Q000032:analysis*; D057285:Precision Medicine; D055815:Young Adult
chemical_list: D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; C071447:ERCC1 protein, human; D004720:Endonucleases; D002945:Cisplatin; D005472:Fluorouracil