title: Incidence of humoral hypercalcemia of malignancy among hypercalcemic patients with cancer.
abstract: BACKGROUND
  Malignancy-associated hypercalcemia (MAHC) is the most common cause of hypercalcemia among hospitalized patients. MAHC can result from the production of parathyroid hormone related peptide (PTHrP) which is known as humoral hypercalcemia of malignancy (HHM). HHM is commonly thought to account for approximately 80% of MAHC.
  
  
  METHODS
  We conducted a 12-year review of PTHrP testing at our institution to establish the prevalence of HHM among patients with MAHC.
  
  
  RESULTS
  A total of 524 PTHrP immunoassays were performed during the study period of which 470 tests qualified for inclusion in the analysis. Evidence of malignancy was found for 242 of 470 patients (51%). No etiology could be determined for 98 cases of MAHC (40%) and increased PTHrP contributed to 92 cases (38%) of MAHC. Age, race and gender were not associated with HHM. Increased PTHrP was observed at initial malignancy diagnosis in 20% of cases. PTHrP was never increased outside of the context of malignancy.
  
  
  CONCLUSIONS
  The prevalence of HHM among patients with MAHC is likely to be lower than previously described.
authors.affiliation: Department of Pathology and Immunology, Washington University, St Louis, MO, United States.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Szymanski
authors.affiliation: Department of Pathology and Immunology, Washington University, St Louis, MO, United States.
authors.forename: Zaher K
authors.initials: ZK
authors.lastname: Otrock
authors.affiliation: Department of Pathology and Immunology, Washington University, St Louis, MO, United States.
authors.forename: Khushbu K
authors.initials: KK
authors.lastname: Patel
authors.affiliation: Department of Pathology and Immunology, Washington University, St Louis, MO, United States. Electronic address: mscott@path.wustl.edu.
authors.forename: Mitchell G
authors.initials: MG
authors.lastname: Scott
mesh_terms: D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000150:complications* / Q000453:epidemiology* / Q000378:metabolism; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D010257:Paraneoplastic Syndromes / Q000150:complications* / Q000453:epidemiology* / Q000378:metabolism; D044162:Parathyroid Hormone-Related Protein / Q000378:metabolism
chemical_list: D044162:Parathyroid Hormone-Related Protein
keywords: Hypercalcemia; Malignancy; PTHrP; Prevalence