Hypercalcaemia in patients with breast cancer: Patterns and treatment outcomes among in-patients in a Malaysian tertiary healthcare facility

Purpose: To assess the patterns of use of bisphosphonate therapies for hypercalcaemia in breast cancer patients, and their outcomes.
Methods: A retrospective chart review study of breast cancer patients hospitalised between 2009 and 2014 at Penang Hospital, a public tertiary hospital in Malaysia was conducted. Patients with mild (total serum calcium = 10.5 - 11.9 mg/dl); moderate (12 - 12.9 mg/dl), and severe (≥13 mg/dl) hypercalcaemia at cancer diagnosis or during cancer treatment were included. Relevant data were extracted from medical records analyzed statistically.
Results: From the records, 1,023 breast cancer patients were identified, 164 of which had hypercalcaemia at cancer diagnosis or during cancer treatment. About 25 % of the hypercalcaemic patients had advanced-stage cancer, while 20 % had severe hypercalcaemia. Regarding the pattern of bisphosphonate use, the results showed that more than half of the patients received pamidronate as first-line treatment; about a quarter were treated with zoledronic acid, while others received only normal saline. These treatments produced significant reductions in serum calcium levels relative to baseline values.
Conclusion: Although zoledronic acid is considered as the treatment of choice for hypercalcemia of malignancy, the current study found that the first line treatment used for hypercalcemia is pamidronate, mainly because its cost is lower than that of zoledronic acid.