title: Repeat biopsy of primary disease negatively affects the outcome of patients with nasopharyngeal cancer treated with definitive intensity-modified radiotherapy: a cohort analysis of 795 patients.
abstract: OBJECTIVE
  To determine whether pretreatment repeat biopsy of nasopharynx is associated with an impaired outcome in nasopharyngeal carcinoma patients in an intensity-modified radiotherapy era.
  
  
  METHODS
  We performed a retrospective data review of the association between pretreatment nasopharyngeal biopsy and outcomes for all nasopharyngeal carcinoma patients treated at our center between January 2007 and December 2011. Of the 720 patients enrolled, 693 (96.3%) were diagnosed after initial biopsy and 27 (3.7%) after repeat biopsy. Five-year cancer-specific survival, disease-free survival and distant metastasis-free survival for the two groups were compared using univariate and multivariate analyses to evaluate the effects of repeat biopsy on the outcome.
  
  
  RESULTS
  Five-year estimated cancer-specific survival (75.9 vs. 88.5%, P= 0.045) and disease-free survival (63.3 vs. 77.1%, P= 0.041) were significantly poorer in the repeat biopsy group than the initial biopsy group. After adjustment for other prognostic factors (age, gender, T and N stage), pretreatment biopsy remained independently associated with poorer both 5-year cancer-specific survival and disease-free survival. The hazard ratios for cancer-specific survival and disease-free survival in the repeat biopsy group were 2.73 (95% confidence interval 1.09-6.82) and 2.22 (95% confidence interval 1.12-4.37) compared with the initial biopsy group (reference), respectively. The repeat biopsy group also had a higher risk of distant failure compared with the initial biopsy group (hazard ratio 2.82, 95% confidence interval 1.22-6.51, P= 0.015).
  
  
  CONCLUSIONS
  Pretreatment repeat biopsy of nasopharynx has a detrimental effect on survivals of nasopharyngeal carcinoma patients, which may be partly due to an increased frequency of distant metastasis.
authors: Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, People's Republic of China.
authors: Feng
authors: F
authors: Jiang
authors: Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, People's Republic of China.
authors: Ting
authors: T
authors: Jin
authors: Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, People's Republic of China.
authors: Xing-Lei
authors: XL
authors: Feng
authors: Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, People's Republic of China.
authors: Qi-Feng
authors: QF
authors: Jin
authors: Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, People's Republic of China chenxiaozhongfy@163.com.
authors: Xiao-Zhong
authors: XZ
authors: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009305:Nasopharynx / Q000000981:diagnostic imaging / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: biopsy; intensity-modulated radiotherapy; nasopharyngeal carcinoma; outcome