SURVIVAL IN BREAST-CANCER PATIENTS AFTER THE FIRST EPISODE OF HYPERCALCEMIA

Objectives. To investigate hypercalcaemia (serum ionized calcium (S-Ca 2+) > 1.35 mmol L-1) in breast cancer patients before and after the in troduction of bisphosphonates and the effect of disease- and treatment -related factors on survival, Design. Prospective and retrospective re gistration of covariates. Setting, A department of oncology in a unive rsity hospital, Subjects, A consecutive cohort of 212 hypercalcaemic p atients never treated with bisphosphonate was identified prospectively (period 1) and 193 patients with metastases were classified into thre e groups: mild (S-Ca2+ < 1.48: n = 102), moderate (1.48 less than or e qual to S-Ca2+ less than or equal to 1.60, n = 41), and severe hyperca lcaemia (S-Ca2+ > 1.60 mmol L-1; n = 50). Fifty-one patients with seve re hypercalcaemia all treated with bisphosphonate except one were iden tified retrospectively (period 2). Results. For period 1 median surviv al was 6.7 months. Survival was significantly decreased in the two gro ups with the highest initial S-Ca2+ (P < 0.0001). Median survival time s in severely hypercalcaemic patients from periods 1 and 2 were 1.4 (9 5% confidence interval 0.8-2.1) and 2.2 (95% confidence interval 1.3-3 .1) months, respectively, In a Cox model for period 1 significant cova riates were: WHO performance, extent of metastases, whether systemic a nticancer treatment could be given, and haemoglobin, but not S-Ca2+. C onclusion. Prognosis is poor in hypercalcaemic breast cancer patients with WHO performance 3-4 and advanced metastatic disease when effectiv e systemic treatment can no longer be offered, Bisphosphonate treatmen t does not seem to improve survival in severe hypercalcaemia. Antihype rcalcaemic treatment of mild malignancy-associated hypercalcaemia appe ars not to be vital. Therapeutic efforts should be aiming at patients with moderate hypercalcaemia.