We compared the ability to diagnose skeletal
metastasis between serum
prostate specific antigen (PSA), C-terminal propeptide of blood
type I procollagen (
PICP), and urine
type I collagen-crosslinked
N telopeptide (NTx) in
prostate cancer patients. In sixty-nine patients with
prostate cancer, bone scintigraphy was performed, and serum PSA and
PICP and urine NTx were measured. The median level of serum PSA in the osseous
metastasis-negative group (n = 33) was 0.80 ng/ml being significantly lower as compared to the osseous
metastasis-positive group (n = 36, 7.70 ng/ml) (p < 0.0001). The serum
PICP and urine NTx/Cr levels appeared lower in the osseous
metastasis-negative group than the osseous
metastasis-positive group, but there was no significant difference. Logistic regression analysis showed that ability to diagnose skeletal
metastasis of serum PSA was 68.1% and superior to those of serum
PICP (56.5%) and urine NTx/Cr (53.6%). Serum PSA improved the ability to diagnose skeletal
metastasis when combined with serum
PICP or urine NTx/Cr. When patients were grouped according to the extent of disease grade (EOD grade) nomenclature, Spearman's correlation coefficient by rank showed that serum PSA was most significantly correlated with EOD grade (p < 0.0001). In 14 patients whose skeletal
metastases progressed or regressed, the change of serum PSA more clearly separated the osseous
metastasis-regression group and osseous
metastasis-progression group than did serum
PICP and urine NTx/Cr. Serum PSA was more reliable than
bone resorption and formation markers produced by crosslinking of
type I collagen.