title: Bone scan can be spared in asymptomatic prostate cancer patients with PSA of <=20 ng/ml and Gleason score of <=6 at the initial stage of diagnosis.
abstract: OBJECTIVE
  According to several guidelines, it is acceptable to spare a bone scan in the patients who are newly diagnosed with low-risk prostate cancer. Our aim is to clarify a suitable group whereby a bone scan could be spared at the initial staging of prostate cancer.
  
  
  METHODS
  Consecutive 857 patients who were newly diagnosed from 2004 through 2009 and received bone scans using technetium 99m methylene diphosphonate at the initial staging were enrolled. The proportion of positive bone metastases by age distribution, prostate-specific antigen level at diagnosis, Gleason score and clinical T stage were evaluated. Univariate and multivariate logistic regression analyses were performed to identify the predictors of positive bone metastases.
  
  
  RESULTS
  Of all 857 patients, 40 patients (4.7%) showed bone metastases. Patients with higher age, prostate-specific antigen level, clinical stage and Gleason score showed significantly higher rate of bone metastases (P < 0.001). In univariate logistic regression analyses, age, prostate-specific antigen level, clinical stage and Gleason score were independent predictors of bone metastasis. The multivariate analysis showed that both the prostate-specific antigen level >50 ng/ml and the Gleason score ≥4 + 3 were independent predictors of bone metastases.
  
  
  CONCLUSIONS
  The incidences of bone metastases in patients with a prostate-specific antigen level of ≤20 ng/ml and Gleason score of ≤6 were reasonably low. Collectively, a bone scan is not necessary as a routine examination for these patients at their initial staging of prostate cancer.
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan. sendo@naramed-u.ac.jp
authors.forename: Nobumichi
authors.initials: N
authors.lastname: Tanaka
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shinkai
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nakai
authors.forename: Masaomi
authors.initials: M
authors.lastname: Kuwada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Anai
authors.forename: Makito
authors.initials: M
authors.lastname: Miyake
authors.forename: Akihide
authors.initials: A
authors.lastname: Hirayama
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hirao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000517:prevention & control / Q000556:secondary; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000473:pathology*; D011877:Radionuclide Imaging
chemical_list: D017430:Prostate-Specific Antigen