title: Prostate-Specific Antigen fluctuation: what does it mean in diagnosis of prostate cancer?
abstract: OBJECTIVE
  To investigate whether prostate-specific antigen (PSA) fluctuation correlates with a prostate cancer and to assess whether PSA fluctuation could be used for diagnosis of prostate cancer.
  
  
  METHODS
  Our study included 229 patients who were performed a prostate biopsy (non-cancer group, 177; prostate cancer group, 52). Enrolled patients were provided twice PSA tests within 6 months. PSA fluctuation (%/month) was defined as a change rate of PSA per a month. Independent t test was used to compare between two groups. Receiver operator characteristic curve was used to assess the availability as a differential diagnostic tool and the correlation. Simple linear regression was performed to analyze a correlation between PSA fluctuation and other factors such as age, PSA, PSA density, and prostate volume.
  
  
  RESULTS
  There were significant differences in PSA, PSA density, percentage of free PSA, and PSA fluctuation between two groups. PSA fluctuation was significantly greater in non-cancer group than prostate cancer group (19.95 ± 23.34%/month vs 9.63 ± 8.57%/ month, P=0.004). The most optimal cut-off value of PSA fluctuation was defined as 8.48%/month (sensitivity, 61.6%; specificity, 59.6%; AUC, 0.633; P=0.004). In a simple linear regression model, only PSA level was significantly correlated with PSA fluctuation.
  
  
  CONCLUSIONS
  Patients with wide PSA fluctuations, although baseline PSA levels are high, might have a low risk of diagnosis with prostate cancer. Thus, serial PSA measurements could be an option in patients with an elevated PSA level.
authors.affiliation: Department of Urology, Kwangju Christian Hospital, Gwangju.
authors.forename: Jun Seok
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Departments of Urology and Radiology, Research Institute of Medical Sciences, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Je-Guk
authors.initials: JG
authors.lastname: Ryu
authors.affiliation: Departments of Urology and Radiology, Research Institute of Medical Sciences, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Jin Woong
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Departments of Urology and Radiology, Research Institute of Medical Sciences, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Eu Chang
authors.initials: EC
authors.lastname: Hwang
authors.affiliation: Departments of Urology and Radiology, Research Institute of Medical Sciences, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Seung Il
authors.initials: SI
authors.lastname: Jung
authors.affiliation: Departments of Urology and Radiology, Research Institute of Medical Sciences, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Taek Won
authors.initials: TW
authors.lastname: Kang
authors.affiliation: Departments of Urology and Radiology, Research Institute of Medical Sciences, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Dongdeuk
authors.initials: D
authors.lastname: Kwon
authors.affiliation: Departments of Urology and Radiology, Research Institute of Medical Sciences, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Kwangsung
authors.initials: K
authors.lastname: Park
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D001706:Biopsy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology*; D012372:ROC Curve; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen