Clinical Usefulness of Serum Carboxyterminal Propeptide of Type I Procollagen and Pyridinoline Cross-linked Carboxyterminal Telopeptide of Type I Collagen in Patients with Prostate Cancer

A study was undertaken to evaluate the clinical usefulness ofmeasurements of serum concentrations of the carboxyterminalpropeptide of type I procollagen (PICP) and the pyridinolinecross-linked carboxyterminal telopeptide of type I collagen(ICTP) as parameters of bone metastasis in patients with prostatecancer. Serum PICP, ICTP, prostate-specific antigen (PSA), andalkaline phosphatase (ALP) were evaluated in 82 patients withprostate cancer and 26 patients with benign prostatic hyperplasia(BPH). These markers were measured serially in 16 prostate cancerpatients during treatment. The serum levels of PICP, ICTP, ALP,and PSA were significantly higher in prostate cancer patientswith bone metastasis than in patients with either BPH or prostatecancer without bone metastasis. Although the rate of detectionof bone metastasis with PICP and ICTP was slightly lower thanthat with PSA determined by the receiver operating characteristiccurve, the correlation between both PICP and ICTP and the extentof disease was much higher than that of PSA. PICP and ICTP levelsvaried with ALP and PSA levels, the patient's clinical courseafter the start of endocrine therapy and the progression ofbone metastasis. The levels of PICP and ICTP did not changesubstantially in patients who developed local regrowth or lymphnode metastasis, and decreased as bone metastases respondedto radiotherapy. PICP and ICTP thus reflect the metastatic burdenin bone and are useful for monitoring the response of bone metastasisto therapy.