ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

Abstract: FR-PO243

Immobilization-Associated Hypercalcemia in Patients with Malignancy in the Hospital Setting: A Cohort Study

Session Information

Category: Onconephrology

  • 1700 Onconephrology

Authors

  • Kanduri, Swetha Rani, Ochsner Medical Center, New Orleans, Louisiana, United States
  • Stark, Ana Isabel, Ochsner Medical Center, New Orleans, Louisiana, United States
  • Smith, Alexander M., Ochsner Medical Center, New Orleans, Louisiana, United States
  • Lam, Walter, Ochsner Medical Center, New Orleans, Louisiana, United States
  • Velez, Juan Carlos Q., Ochsner Medical Center, New Orleans, Louisiana, United States
Background

Malignancy-associated hypercalcemia (MAH) is not uncommon in patients with cancer. Direct bone invasion (primary bone cancer, bone metastasis, multiple myeloma) and humoral hypercalcemia (elevated PTH, PTH-related peptide (PTHrP) and calcitriol) are the predominant etiologies. Although a significant proportion of patients with malignancy have poor functional status, immobilization-associated hypercalcemia (Immob-HCa) is not well recognized in this population. We examined the relative contribution of Immob-HCa to all causes of MAH in the hospital setting.

Methods

A retrospective review of medical records was conducted searching for cases of MAH over a 3-year period. Hypercalcemia was defined as serum calcium >11.0 mg/dL. Definite Immob-HCa was defined as presence of immobility >1 week prior to admission or ECOG score >4, needing complete assistance, combined with absence of disqualifying laboratory data (PTH >60 ng/dL, 1,25 vitamin D >70 pg/mL, 25 vitamin D >80 ng/mL, PTHrP >2.5 pmol/L) monoclonal gammopathy, lytic lesion by imaging or alternative etiology (sarcoidosis, exposure to thiazide, or calcium or vitamin D supplementation). Probable Immob-HCa was defined as documented immobility and absence of alternative etiology, but incomplete laboratory data.

Results

A total of 145 patients with in-hospital MAH were identified. The median age was 68 (33-92), 45% women, 64% white, 31% self-identified black; median peak serum calcium was 12.1 (11.2-17.8) mg/dL. High ionized calcium was verified in 41 (28%) cases. 74 (51%) had evidence of bone metastasis (including primary bone cancer), multiple myeloma accounted for 7 (5%) cases, elevated PTH for 10 (7%) cases, PTHrP for 11 (7%) and elevated calcitriol for 3 (2%) cases. One case was categorized as Definite Immob-HCa and 4 cases as Probable Immob-HCa. The etiology of MAH was undetermined in 35 (24%) cases. Thus, Immob-HCa accounted for up to 4% (5/145) of in-hospital MAH. Concomitant acute kidney injury (AKI) was present in 3 out of 5 (60%) cases of Immob-HCa.

Conclusion

Immob-HCa accounted for approximately 1 in 29 of cases of in-hospital MAH and is accompanied by AKI in about half of the cases. Notably, incomplete diagnostic work up for MAH was common and may underestimate the incidence of Immob-HCa.