title: Biochemical failure after carbon ion radiotherapy for prostate cancer.
abstract: OBJECTIVE
  Biochemical failure after radiotherapy for prostate cancer occurs infrequently, but some cases progress to a poor outcome. The aim of this study was to examine prognosis after biochemical failure.
  
  
  METHODS
  A total of 728 patients were treated with carbon ion radiotherapy, and biochemical failure occurred in 90 (12.4%). Their outcomes were examined according to risk factors, histological findings, and androgen deprivation therapy (ADT).
  
  
  RESULTS
  Biochemical failure rates were 12%, 6%, and 15% in low-, intermediate- and high-risk patients. Most patients responded favorably to salvage therapy. Some high-risk patients (25%) progressed to poor outcome; half experienced failure after ADT, while the rest during ADT, indicating that ADT had a slight influence. Patients who died from their disease had approximately two years of biochemical failure-free time and three years of survival after failure. Their tumor showed the presence and the increased proportion of histologically high-grade growth patterns.
  
  
  CONCLUSIONS
  Histological growth patterns and short biochemical failure-free time are prognostic factors for poor outcome regardless of ADT.
authors: Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan. shimajun@opal.famille.ne.jp
authors: Jun
authors: J
authors: Shimazaki
authors: Hiroshi
authors: H
authors: Tsuji
authors: Hitoshi
authors: H
authors: Ishikawa
authors: Tadashi
authors: T
authors: Kamada
authors: Masaoki
authors: M
authors: Harada
authors: Koichiro
authors: K
authors: Akakura
authors: Hiroyoshi
authors: H
authors: Suzuki
authors: Tomohiko
authors: T
authors: Ichikawa
authors: Hirohiko
authors: H
authors: Tsujii
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D002250:Carbon Radioisotopes / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000532:radiotherapy*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D002250:Carbon Radioisotopes