title: Development of a formula to predict parathyroid carcinoma in patients with primary hyperparathyroidism.
abstract: BACKGROUND
  Cure of parathyroid carcinoma (PC) requires initial en bloc resection, including resection of all tumor-bearing tissue, with hemithyroidectomy and dissection of the central lymph node compartment. Unfortunately, no reliable preoperative criteria have yet been assessed to indicate a high likelihood of PC. Thus, the aim of the present study was to develop a formula to indicate preoperatively the presence of PC.
  
  
  METHODS
  A prospective database of 1,363 patients with primary hyperparathyroidism (pHPT) was screened for patients with PC. Age, gender, surgical procedures, laboratory data, and follow-up results were evaluated and compared to a group of patients with benign pHPT. Based on preoperative serum calcium (Ca) and parathyroid hormone (PTH) levels, as well as patients' age at the time of diagnosis, a formula was developed by a multivariate logistic model that estimates the individual risk for PC.
  
  
  RESULTS
  Between 1987 and 2008, 19 patients with PC were identified. Ca (3.8 ± 0.3 vs 2.9 ± 0.3 mmo/l; p = 0.0002) and PTH levels (1,250 ± 769 vs 194 ± 204 pg/ml; p = 0.0030) were significantly higher in patients with PC than in those with benign pHPT. Patients with PC were also significantly younger than patients with benign pHPT (48.9 ± 12.1 vs 59.1 ± 13.8 years; p < 0.05). With a ≥5 % probability that a given patient suffered from PC, the sensitivity and specificity to identify the disease were 100 and 30 %, respectively, with the new Ca, PTH, and age based logarithmic formula.
  
  
  CONCLUSIONS
  The new logarithmic formula can be used to calculate the individual risk for PC. If the calculated individual risk exceeds 5 %, en bloc resection seems to be justified to provide long-term cure in case of PC.
authors: Department of Visceral, Thoracic and Vascular Surgery, University Hospital Marburg, Baldingerstraße, 35043 Marburg, Germany. karakas@med.uni-marburg.de
authors: Elias
authors: E
authors: Karakas
authors: Hans-Helge
authors: HH
authors: Müller
authors: Vladimir K
authors: VK
authors: Lyadov
authors: Stephanie
authors: S
authors: Luz
authors: Ralph
authors: R
authors: Schneider
authors: Matthias
authors: M
authors: Rothmund
authors: Detlef K
authors: DK
authors: Bartsch
authors: Katja
authors: K
authors: Schlosser
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000150:complications*; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D010282:Parathyroid Neoplasms / Q000150:complications* / Q000175:diagnosis*; D011446:Prospective Studies