Ergin AYDEMİR, Ayşe Ocak DURAN, Berkan KARABUĞA, Mehmet Emin YILMAZ, Osman Bilge KAYA, Sedef Tatar BOLAT, Fatih TAY, Mustafa BÜYÜKKÖR
Anatolian Current Medical Journal - 2026;8(4):638-644
Aims: Malignancy-associated hypercalcemia (MAH) is a severe metabolic complication affecting 2-3% of cancer patients, with higher prevalence in multiple myeloma (20-30%), lung cancer (12-15%), and breast cancer (10-20%). Median survival following MAH diagnosis ranges from 25 to 68 days, highlighting its status as an oncological emergency. This retrospective study examines demographic characteristics, clinical findings, treatment responses, and survival outcomes in patients with malignant hypercalcemia, with particular emphasis on the influence of bone metastasis on the presentation, severity, and management of hypercalcemia. Methods: This retrospective cohort study included 124 cancer patients aged 18 years or older who were hospitalized for malignant hypercalcemia at a tertiary oncology training and research hospital between January 2018 and December 2023. Inclusion criteria were a corrected serum calcium level of at least 10.5 mg/dl and a diagnosis of active malignancy. Collected data encompassed demographic characteristics, primary cancer diagnosis, disease stage, presence of bone metastases, laboratory values, treatment modalities, treatment responses, and survival times. Statistical analyses were performed using SPSS 26.0. Survival was assessed using the Kaplan-Meier method, and inter-group comparisons were performed using the log-rank test. A p-value below 0.05 was considered statistically significant. Results: The median age of the cohort was 58 years (range: 21-90 years), with an equal gender distribution (50.0% female, 50.0% male). The median corrected calcium level at diagnosis was 12.77 mg/dl (range: 10.5-21.0 mg/dl). Bone metastases were identified in 66.9% of patients at the time of malignant hypercalcemia diagnosis, with primary tumor distribution as follows: breast cancer 33.9%, lung cancer 20.1%, and other cancers 46.0%. Treatment modalities comprised bisphosphonates (66.9%), hydration alone (23.4%), and denosumab (9.7%). The median time to normalization of hypercalcemia was 4.0 days (range: 1-16), varying by treatment: hydration-diuretic 3.0 days, bisphosphonates 4.0 days, and denosumab 3.0 days (p=0.032). After hypercalcemia diagnosis, the median survival was 2.0 months (range: 0-60), with a 75% mortality rate within 6 months. Prior bisphosphonate use correlated with improved survival in breast cancer patients (57.0 vs 22.0 months, p=0.002), but not in lung cancer patients (8.0 vs 8.0 months, p>0.05). At the end of follow-up, 91.9% of patients had died. Conclusion: Malignant hypercalcemia mostly affects patients with advanced cancer and a high rate of bone metastasis (66.9%). However, having bone involvement did not independently affect survival or the time it took for calcium levels to return to normal. The only factor that predicted poor survival after hypercalcemia was Eastern Cooperative Oncology Group (ECOG) performance status, which suggests that systemic factors are more important than the extent of bone disease in determining outcomes. The longer survival seen in breast cancer patients who had used bisphosphonates before should be viewed with caution, as this may be due to immortal time bias and confounding by indication. Overall, these results highlight the poor outlook for malignant hypercalcemia and stress the need for early detection and proper treatment.
