The course of the urinary DPD-crosslink secretion in metastatic breast cancer--a possibility for response assessment.
BACKGROUND
Urinary deoxypyridinoline (DPD)-crosslinks have been shown to be a highly specific parameter for type I collagen metabolism.


METHODS
In a prospective breast cancer study, urine samples were collected in after-care patients and in patients with bone metastases. DPD-crosslinks were measured every three weeks using a fully automated chemiluminescence immunoassay. Bone metastases were confirmed by bone scan and/or x-ray, and were followed-up over six months. To validate the test, a receiver operating characteristics (ROC)-curve was set up to find the DPD cut-off concentration which separates patients with no evidence of disease (NED) from patients with bone metastases.


RESULTS
73 breast cancer patients (41 with NED, 32 with bone metastases) were included into the ROC analysis. At a DPD cut-off value of 8 nmol/mmol creatinine, we found the best sensitivity (84.4%) for the detection of bone metastases with a specificity of 70.7%. Patients with stable bone disease under intravenous pamidronate treatment (90 mg q3w) and specific therapy had a significant (p = 0.007) fall of the DPD-crosslinks in comparison to the progressive subset with 72.7% falling below 8 nmol/mmol.


CONCLUSIONS
We conclude that the net bone turnover is not increased at a DPD-crosslinks elimination < 8 nmol/mmol.
Lüftner
D
D
Medizinische Klinik und Poliklinik II, Humboldt-Universität Berlin, Germany. Diana.Lueftner@rz.hu-berlin.de
Günther
S
S
Flath
B
B
Müller
C
C
Echteroff
K
K
Mergenthaler
H G
HG
Wernecke
K D
KD
Possinger
K
K
D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000652:urine*; D014408:Biomarkers, Tumor / Q000652:urine*; D001859:Bone Neoplasms / Q000175:diagnosis / Q000556:secondary* / Q000652:urine; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy / Q000652:urine*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D012372:ROC Curve; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000596:Amino Acids; D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C036020:deoxypyridinoline