Significance of Free to Total PSA Ratio in Men with Slightly Elevated Serum PSA Levels: A Cooperative Study

Manabu Kuriyama, Yukimichi Kawada, Yoichi Arai, Hiroshi Maeda, Shin Egawa, Ken Koshiba, Kyoichi Imai, Hidetoshi Yamanaka

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


Background: The ratio of free PSA in total PSA (f/t) has been reported to improve the diagnostic accuracy of prostate cancer in the group with slightly elevated serum PSA values. In Japanese cases, the clinical significance of f/t is still controversial. Methods: The diagnostic significance of f/t in serum for prostate cancer was evaluated in a cooperative study. A total of 77 cases with prostate cancer and 224 with non-prostate cancer showing less than 20 ng/ml of total PSA were evaluated. Results: Serum total and free PSA values were not affected by storage at 25°C for 2 days. The determination of f/t was useful in the cases with a serum total PSA of 5.1-10 ng/ml; the specificity was 60% with a sensitivity of 90% at an f/t of 0.148. The positive predictive value for diagnosis of prostate cancer also increased to 54% from 34% of that in total PSA alone. In the range of 4.1-10 ng/ml, the cut-off value of f/t was 0.155 for obtaining relatively high specificity; sensitivity was 85% and specificity was 56.5%. Conclusions: Thus, the determination of f/t was considered to be an effective tool for discriminating the non-prostate cancer cases from those of prostate cancer.

Original languageEnglish
Pages (from-to)661-665
Number of pages5
JournalJapanese journal of clinical oncology
Issue number11
Publication statusPublished - 1998
Externally publishedYes


  • Fit ratio of PSA
  • PSA gray zone
  • Prostate cancer
  • Screening PSA

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research


Dive into the research topics of 'Significance of Free to Total PSA Ratio in Men with Slightly Elevated Serum PSA Levels: A Cooperative Study'. Together they form a unique fingerprint.

Cite this