[Hydroxyproline in the diagnosis of bone metastases in breast cancer].

15 patients with breast cancer and proven bone metastases have been studied. Free serum and total urinary hydroxyproline were measured and the ratio (hydroxyproline/creatinine) - 100 in a morning urine specimen was calculated. The preliminary results show elevated free serum hydroxyproline in 8 of 15 patients; total urinary hydroxyproline in a 24-h collection and the ratio hydroxyproline/creatine in a morning urine specimen were elevated in all cases. These results agree with those of the literature. Further studies of free hydroxyproline and of the ratio hydroxyproline/ creatinine in a morning urine specimen in similar patients with provide more information on the possibility of using these measurements, alone or in combination, for the early detection or follow-up under therapy of bone metastases.