Long-term follow up of breast cancer patients treated for hypercalcaemia with aminohydroxypropylidene bisphosphate (APD).

No systematic data are available about the long-term follow up of breast cancer patients treated with amino-hydroxypropylidene bisphosphate (APD) for hypercalcaemia and about the results of APD treatment of recurrent hypercalcaemia in these patients. Treatment with intravenous APD (10-15 mg daily until normalization of the serum calcium level) normalized serum calcium in 29 of 31 patients with hypercalcaemia due to advanced breast cancer. Survival in these 29 patients varied between 8 and 693 days (median 140 days) and 7 patients achieved a partial remission or stabilisation of disease during subsequent anti-tumor therapy. In 16 of the 29 patients in whom APD treatment was initially successful, hypercalcaemia recurred after a median period of 65 days. Eleven of these patients received a second course of APD, which was equally successful as the first in terms of percentage of patients with normalization of serum calcium, total dose of APD needed, and duration to normalization of serum calcium. Recurrent hypercalcaemia occurred significantly faster after the second successful APD course (median 17 days) than after the first (median 65 days). When only patients with progressive disease were taken into account, recurrence of hypercalcaemia usually occurred early, both after a first (median 23 days) and after a second successful APD course (median 17 days). Normalization of serum calcium occurred in 4 of 6 patients receiving a third APD course, in all 3 patients receiving a fourth, and in 1 of 2 patients receiving a fifth course.(ABSTRACT TRUNCATED AT 250 WORDS)