title: Radiation-induced secondary malignancy in prostate cancer: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To investigate the risk of radiation-induced secondary malignancy in patients with prostate cancer.
  
  
  METHODS
  We identified 690 references from PubMed, Embase and the Cochrane Library before August 1, 2012, that reported secondary malignancy in patients with prostate cancer after receiving radiation therapy (RT), and finally four studies were included. We calculated summary estimates using random-effects meta-analysis.
  
  
  RESULTS
  The overall standardized incidence ratio (SIR) of secondary malignancy in patients with prostate cancer receiving RT to the general population was 1.14 (95% CI 1.04-1.32). In the subgroup analysis, no increment in radiation-induced secondary malignancy risk was detected. In terms of SIR with different follow-up intervals, there was no difference in SIR (>6 months; <5 years) (SIR = 1.19, 95% CI 0.75-1.89) and SIR (>5 years; <10 years) (SIR = 1.39, 95% CI 0.87-2.23). When the follow-up extended to >10 years, a significantly increased secondary malignancy risk was observed (SIR = 1.45, 95% CI 1.23-1.72). There is no significantly increased secondary malignancy risk in patients receiving no RT.
  
  
  CONCLUSIONS
  RT is associated with increased secondary malignancy in patients with prostate cancer; this effect only become conspicuous more than 10 years after treatment.
authors.affiliation: Department of Urology, West China Hospital, Sichuan University, Chengdu, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jin
authors.forename: Turun
authors.initials: T
authors.lastname: Song
authors.forename: Shi
authors.initials: S
authors.lastname: Deng
authors.forename: Kunjie
authors.initials: K
authors.lastname: Wang
mesh_terms: D006801:Humans; D015994:Incidence; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D016609:Neoplasms, Second Primary / Q000209:etiology*; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D011878:Radiotherapy / Q000009:adverse effects; D012107:Research Design; D012307:Risk Factors; D016896:Treatment Outcome