title: Matched-cohort analysis of patients with prostate cancer followed with observation or treated with three-dimensional conformal radiation therapy.
abstract: OBJECTIVE
  To compare the outcome of similar patients with prostate cancer treated by either observation or three-dimensional conformal radiation therapy (3-DCRT).
  
  
  METHODS
  The study included 69 patients with nonmetastatic prostate cancer who were observed only; the indications included indolent disease, significant medical comorbidities and refusal of treatment. Of these, 62 patients had palpable T1-T2a and seven T2b-T3a disease, a median Gleason score of 6 and a median initial prostate-specific antigen (PSA) level of 5.3 ng/mL. A matched-cohort analysis of 69 patients, based on palpation T category, Gleason score and initial PSA, was used to compare the outcome between the observation and 3-DCRT groups. The median radiation dose for latter was 72 Gy.
  
  
  RESULTS
  The median follow-up for the observed patients was 49 months. The 5- and 8-year actuarial rates of freedom from distant metastases were 100% and 93%, respectively, and the actuarial overall survival rates 94% and 73%, respectively. Seven observed patients had local disease progression on physical examination. Four patients who initially were observed received radiation therapy later for a rising PSA and/or local disease progression. For the 69 matched 3-DCRT patients, the overall 5-year rate for no biochemically evident disease was 74%. The respective 5- and 8-year actuarial rates of freedom from distant metastases were 95% and 95%, and actuarial overall survival rates 95% and 75%. There were no significant differences in distant metastasis and overall survival rates between the groups, and no deaths from prostate cancer in either group.
  
  
  CONCLUSIONS
  Observation is a reasonable alternative to treatment in selected patients. During the 5-year follow-up the progression rates were relatively low, and there was no difference in distant metastasis or overall survival between the groups. As the follow-up was short a longer follow-up is needed to determine whether the outcome of those patients who chose observation will remain comparable to that in those undergoing immediate 3-DCRT.
authors.affiliation: Departments of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Noel M
authors.initials: NM
authors.lastname: Kramer
authors.forename: Eric M
authors.initials: EM
authors.lastname: Horwitz
authors.forename: Robert G
authors.initials: RG
authors.lastname: Uzzo
authors.forename: Alexandra L
authors.initials: AL
authors.lastname: Hanlon
authors.forename: Gerald E
authors.initials: GE
authors.lastname: Hanks
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000401:mortality / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000401:mortality / Q000532:radiotherapy*; D020266:Radiotherapy, Conformal / Q000379:methods*; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen