前立腺癌患者における骨転移および続発性骨粗鬆症診断に対する尿中NTX測定の有用性

Abstract

〔目的〕骨代謝マーカーであるtype I collagen cross-linked N-telopeptides(NTX)の尿中濃度は骨粗鬆症,副甲状腺機能亢進症および悪性腫瘍の骨転移診断に有用であると言われている.今回我々は前立腺患者の尿中NTXを測定し,骨転移やホルモン療法による続発性骨粗鬆症の診断に対する有用性について検討を行った.〔対象と方法〕前立腺癌と診断された51症例に対して骨代謝マーカーである尿中NTX,血中pyridinoline cross-linked carboxyterminal telopeptide of type I collagen(ICTP),血中carboxyterminal propeptide of type I procollagen(PIPC),血中bone specific alkaline phosphatase(BAP)の測定を行い,それぞれのマーカーとの相関,ホルモン療法および骨転移との関係について検討した.〔結果〕ホルモン療法の期間と尿中NTXには有意な相関(p=0.008)を認めた.治療法に従って2群に分け,各骨代謝マーカーについて検討した.尿中NTXはホルモン療法群で非ホルモン療法群に比して有意に高値を示した.骨転移の有無で2群に分け,各骨代謝マーカーについて検討した.2群間で各骨代謝マーカーに有意差は認められなかった.〔結論〕ホルモン療法の期間と尿中NTXに相関が認められた.長期ホルモン療法の患者では尿中NTXの定期的な測定により,早期の続発性骨粗鬆症の診断および治療に有用であると思われた.[Aim] A high urinary level of type I collagen cross-linked N-telopeptides (NTX), a bone metabolism marker, is associated with osteoporosis, hyperparathyroidism, and bone metastasis in patients with malignant tumors. We investigated the significance and usefulness of measuring the urinary NTX concentration for detection of bone metastasis (BM) and secondary osteoporosis due to hormone therapy (HT) in prostate cancer patients. [Methods] The levels of four bone metabolism markers, urinary NTX, blood ICTP, blood PIPC, and blood BAP, in 51 patients with prostate cancer, were compared with whether patients received HT and the status of bone metastasis. [Results] The duration of HT was significantly correlated with urinary NTX concentration (p=0.008). The urinary NTX concentration was significantly higher in patients who received HT than in patients who did not. There were no significant differences in the levels of the four metabolism markers between patients who did or did not have bone metastasis. [Conclusion] The duration of HT was correlated with the urinary NTX concentration. In patients who have received long-term HT, periodical measurement of urinary NTX level is considered to be useful for early detection and treatment of secondary osteoporosis