Metabolic gaps in bone formation may be a novel marker to monitor the osseous metastasis of prostate cancer.
OBJECTIVE
Although skeletal metastasis is a common complication associated with prostate cancer, assessment of the response of osseous metastasis to therapy is still difficult. To remedy this situation a study of bone formation metabolic markers gaps in patients with prostate cancer and osseous metastasis was done to determine these gaps as clinical markers for the efficacy of therapy against osseous metastasis.


METHODS
The activities of the bone formation markers amino terminal propeptide of type I procollagen (PINP), bone alkaline phosphatase (BAP) and osteocalcin (OC) were measured in 57 and 60 patients with prostate cancer without and with osseous metastasis, respectively. Of the 60 patients with osseous metastasis serial measurements were performed in 31. The status of osseous metastasis at the time of marker measurement was categorized, and the BAP-to-PINP, OC-to-PINP and OC-to-BAP ratios were calculated.


RESULTS
The BAP-to-PINP ratio did not change. However, the OC-to-PINP and OC-to-BAP ratios were significantly different depending on osseous metastasis status. The ratios were high in patients with no osseous metastasis or with metastasis shrinkage (improvement) but low in those in whom metastases were growing and/or spreading (progression). Cutoff levels of OC-to-PINP and OC-to-BAP ratios were determined by comparing ratios with clinical judgment on the response to treatment in all patients. When these cutoffs were applied to the 31 patients, the OC-to-PINP ratio agreed with clinical judgment in 29 (94%) and the OC-to-BAP ratio agreed in 28 (90%).


CONCLUSIONS
Different bone formation markers seem to be sensitive clinical markers for judging the response to therapy of prostate cancer metastasized to bone.
Koizumi
Mitsuru
M
Department of Nuclear Medicine, Cancer Institute Hospital, Toshima-ku, Tokyo, Japan.
Yonese
Junji
J
Fukui
Iwao
I
Ogata
Etsuro
E
D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000097:blood / Q000378:metabolism*; D001859:Bone Neoplasms / Q000097:blood / Q000378:metabolism* / Q000556:secondary*; D001842:Bone and Bones / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood / Q000378:metabolism*; D010446:Peptide Fragments / Q000097:blood / Q000378:metabolism*; D011347:Procollagen / Q000097:blood / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology*; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D010446:Peptide Fragments; D011347:Procollagen; C047202:procollagen Type I N-terminal peptide; D015675:Osteocalcin; D000469:Alkaline Phosphatase