Kataoka A, Yuasa T, Kageyama S, Tsuchiya N, Habuchi T, Iwaki H, Narita M, Okada Y, Yoshiki T
Department of Urology, Shiga University of Medical Science, Otsu, Japan.
Clin Oncol (R Coll Radiol). 2006 Aug;18(6):480-4. doi: 10.1016/j.clon.2006.02.010.
Carboxy-terminal telopeptide of type I collagen (ICTP) is a parameter of bone absorption, and has recently been introduced to monitor bone metastases. The aim of this retrospective study was to investigate the potential of ICTP as a candidate serum marker of bone metastasis in prostate cancer.
Serum markers in 155 men pathologically diagnosed with prostate cancer were measured. The serum levels of ICTP, prostate-specific antigen (PSA), and alkali phosphatase (ALP) were compared to assess the extent of disease (EOD) scores from bone scans and then analysed statistically.
The serum ICTP levels were not well correlated with the EOD scores in the total group of men, men newly diagnosed with prostate cancer, or men previously diagnosed with prostate cancer who were followed up. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ICTP (cut-off value, 5.0 ng/ ml) of the men newly diagnosed with prostate cancer were 78.6%, 88.0%, 78.6%, and 88.0%, respectively. In these men, the specificity and PPV of ALP (cut-off value, 335 IU/l) were 100%, whereas the sensitivity and NPV of PSA (cut-off value, 40 ng/ml) were 100% in this study. The serum levels of ICTP in the men with low ALP (< 335 IU/l) and high PSA (> or = 40 ng/ ml) clearly separated the men with or without bone metastasis, as judged by bone scans.
We found that the ICTP is not a superior serum marker for bone metastases compared with ALP or PSA. Our study suggests, however, that the ICTP measurement is useful in a certain subset of men with the combination of PSA and ALP in distinguishing men with bone metastasis from those without.
I型胶原羧基末端肽（ICTP）是骨吸收的一个参数，最近已被用于监测骨转移。这项回顾性研究的目的是探讨ICTP作为前列腺癌骨转移候选血清标志物的潜力。
检测了155例经病理诊断为前列腺癌的男性的血清标志物。比较ICTP、前列腺特异性抗原（PSA）和碱性磷酸酶（ALP）的血清水平，以评估骨扫描的疾病范围（EOD）评分，然后进行统计学分析。
在所有男性、新诊断为前列腺癌的男性或接受随访的既往诊断为前列腺癌的男性中，血清ICTP水平与EOD评分均无良好相关性。新诊断为前列腺癌的男性中，ICTP（临界值为5.0 ng/ml）的敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）分别为78.6%、88.0%、78.6%和88.0%。在这些男性中，本研究中ALP（临界值为335 IU/l）的特异性和PPV为均为100%，而PSA（临界值为40 ng/ml）的敏感性和NPV均为100%。根据骨扫描判断，碱性磷酸酶水平低（<335 IU/l）且PSA水平高（≥40 ng/ml）的男性中，血清ICTP水平能明显区分有无骨转移的男性。
我们发现，与ALP或PSA相比，ICTP并非骨转移的 superior血清标志物。然而，我们的研究表明，在特定的一部分PSA和ALP联合检测的男性中，检测ICTP有助于区分有无骨转移的男性。
