title: Optimal method for measuring tumor extent in needle biopsy specimens to identify small-volume prostate cancer.
abstract: OBJECTIVE
  To compare various methods for measuring tumor extent in prostate biopsy specimens to identify small-volume prostate cancer.
  
  
  METHODS
  A total of 100 radical prostatectomy specimens were retrospectively analyzed. Receiver operating characteristic analysis was used to compare the abilities of prostate-specific antigen density, and four measures of tumor extent in prostate biopsy specimens - positive core number, greatest percentage of cancer in a single core, greatest length of cancer in cores and total length of cancer in cores - to identify small volume prostate cancer. Four definitions of insignificant cancer volume were used in this analysis: index and total tumor volume <0.5 mL, index tumor volume <1.3 mL and total tumor volume <2.5 mL. Multivariate analysis was also used to evaluate variables for predicting small-volume prostate cancer.
  
  
  RESULTS
  Total length of cancer in cores had the highest areas under the curve of all the measures defining small-volume prostate cancer: index tumor volume <0.5 mL (0.855), total tumor volume <0.5 mL (0.877), index tumor volume <1.3 mL (0.784) and total tumor volume <2.5 mL (0.818). On multivariate analysis total length of cancer in cores was an independent predictive factor for prostate cancers with index tumor volume <0.5 mL (P < 0.001), <1.3 mL (P < 0.001) and total tumor volume <0.5 mL (P < 0.001), respectively.
  
  
  CONCLUSIONS
  Our data suggest that total length of cancer in cores is the optimal measure of tumor extent in prostate biopsy specimens for identifying small-volume prostate cancer.
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Keishi
authors.initials: K
authors.lastname: Kajikawa
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Kent
authors.initials: K
authors.lastname: Kanao
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kobayashi
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Genya
authors.initials: G
authors.lastname: Nishikawa
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yoshizawa
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Zennami
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Kogenta
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sumitomo
mesh_terms: D000368:Aged; D019540:Area Under Curve; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery; D012372:ROC Curve; D047368:Tumor Burden
chemical_list: D017430:Prostate-Specific Antigen
keywords: active surveillance; insignificant cancer; prostate cancer; total length of cancer; tumor extent in biopsy specimens