D. Lufter et al., A comparison of bone-related biomarkers and CA27.29 to assess response to treatment of osseous metastatic breast cancer, ANTICANC R, 20(6D), 2000, pp. 5099-5105
Background: The assessment of bone metastases by clinical examination or im
aging techniques is still considered unreliable. We compared a specific mar
ker of bone resorption, urinary deoxypyridinoline (DPD)-crosslinks, with se
rum calcium (Ca), alkaline phosphatase (AP) and CA27.29, to evaluate the st
atus of bone metastases in patients with breast cancer. Materials and Metho
ds: Second morning voided urine was collected from 2 groups of patient (pts
), those without evidence of disease (n=118), and those with bone metastase
s (n=85) under specific therapy plus pamidronate. DPD and CA27.29 were meas
ured on the automated ACS180(R) system (Bayer Diagnostics(R) Tarrytown, NY;
USA). Receiver operating characteristics (ROC) curves were established for
each of the 4 biomarkers to determine whether they could distinguish the 2
subsets of pts with clinically sufficient validity, and to establish the c
orresponding cut-off values. Results: Neither Ca nor AP was useful in discr
iminating the 2 subgroups. At a DPD cut-off of 13 nmol/mmol, we found a spe
cificity of 69% and a sensitivity of 53% for diagnosing bone metastases. Be
st results, however, were seen for CA27.29. A cut-off value of 30 U/ml resu
lted in a specificity of 62% and a sensitivity of 81%. Conclusions: CA27.29
was the best parameter for the discrimination of stage IV breast cancer wi
th bone metastases. The primary advantage of DPD lies in the monitoring of
bone metastases under specific therapy.