title: Long-term follow-up of prostate cancer patients treated with vaccine and definitive radiation therapy.
abstract: BACKGROUND
  Vaccine therapy in combination with radiation therapy may improve distant and/or local control in prostate cancer. We present long-term follow-up data on the secondary and exploratory endpoints of safety and biochemical failure, respectively, from patients with clinically localized prostate cancer treated definitively with a poxviral vector-based therapeutic vaccine combined with external beam radiation therapy (EBRT).
  
  
  METHODS
  Thirty-six prostate cancer patients received definitive EBRT plus vaccine. A total of 18 patients were treated with adjuvant standard-dose interleukin-2 (S-IL-2) (4 MIU m(-2)) and 18 were treated with very low-dose IL-2 (M-IL-2) (0.6 MIU m(-2)). Seven patients were treated with EBRT alone. Twenty-six patients treated with EBRT plus vaccine returned for follow-up, and we reviewed the most recent labs and clinical notes of the remaining patients.
  
  
  RESULTS
  Median follow-up for the S-IL-2, M-IL-2 and EBRT-alone groups was 98, 76 and 79 months, respectively. Actuarial 5-year PSA failure-free probability was 78%, 82% and 86% (P=0.58 overall), respectively. There were no significant differences between the actuarial overall survival and the prostate cancer-specific survival between the two vaccine arms. Of the 26 patients who returned for follow-up, Radiation Therapy Oncology Group grade ≥2 genitourinary (GU) and gastrointestinal (GI) toxicity was seen in 19% and 8%, respectively, with no difference between the arms (P=1.00 and P=0.48 for grade ≥2 GU and GI toxicity, respectively). In all, 12 patients were evaluated for PSA-specific immune responses, and 1 demonstrated a response 66 months post-enrollment.
  
  
  CONCLUSIONS
  We demonstrate that vaccine combined with EBRT does not appear to have significant differences with regard to PSA control or late-term toxicity compared with standard treatment. We also found limited evidence of long-term immune response following vaccine therapy.
authors.affiliation: Department of Radiation Oncology, University of California at Los Angeles, Los Angeles, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kamrava
authors.forename: A H
authors.initials: AH
authors.lastname: Kesarwala
authors.forename: R A
authors.initials: RA
authors.lastname: Madan
authors.forename: E
authors.initials: E
authors.lastname: Lita
authors.forename: A
authors.initials: A
authors.lastname: Kaushal
authors.forename: K-Y
authors.initials: KY
authors.lastname: Tsang
authors.forename: D J
authors.initials: DJ
authors.lastname: Poole
authors.forename: S M
authors.initials: SM
authors.lastname: Steinberg
authors.forename: T
authors.initials: T
authors.lastname: Ferrara
authors.forename: W
authors.initials: W
authors.lastname: Dahut
authors.forename: J
authors.initials: J
authors.lastname: Schlom
authors.forename: J L
authors.initials: JL
authors.lastname: Gulley
mesh_terms: D000368:Aged; D019496:Cancer Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D007376:Interleukin-2 / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D019496:Cancer Vaccines; D007376:Interleukin-2