Significance of HCG to Distinguish Parathyroid Carcinoma from Benign Disease and in Adding Prognostic Information: A Hospital Based Study from Nepal

Objective: To differentiate between benign and malignant hyperparathyroidism on the basis of excretionof HCG and its malignant isoforms in urine. Materials and
Methods: This hospital based study was carriedout using data retrieved from the register maintained in Manipal Teaching Hospital from 1st January, 2008and 31st August, 2012. The variables collected were urinary HCG and HCG malignant isoform, calcium andparathyroid hormone. Preceding the study, approval was obtained from the institutional research ethicalcommittee. Analysis was by descriptive statistics and testing of hypothesis. A p-value of <0.05 (two-tailed) wasused to establish statistical significance.
Results: Out of the 20 cases, 10 were primary hyperparathyroidismand the remainder were parathyroid carcinomas. The urinary HCG 6.1±0.6 fmol/mgCr was with in normalrange in benign hyperthyroidism but was markedly elevated in three cases of malignant hyperparathyroidism(maximum value of excretion in urine for HCG was 2323 fmol/mgCr). The excretion of malignant isoform ofHCG in urine was 0 in benign hyperparathyroidsm and in four cases of malignant hyperparathyroidism whichfell into the category of persistantly low HCG. The maximum excretion of the malignant isoform of HCG inurine was 1.8, in the category of very high HCG. Calcium and parathyroid hormone were mildly raised in benignparathyroidism, while parathyroid hormone was markedly elevated in cases of malignant hyperparathyroidismfalling into the category of very high HCG.
Conclusions: The excretion of urinary HCG in urine has the abilityto distinguish between parathyroid adenomas and carcinomas and thus has potential to become a marker ofdisease progression in malignant parathyroid disease.