Expression of the alpha- and beta-subunits of human chorionic gonadotropin by subsets of parathyroid cells in states of hyperparathyroidism

Human chorionic gonadotropin measurements in parathyroid carcinoma

OBJECTIVE

Preoperatively, it is difficult to differentiate between parathyroid cancer (PtCa) and severe primary hyperparathyroidism (PHPT) due to a benign tumor. Human chorionic gonadotropin (hCG) is a tumor marker in trophoblastic and nontrophoblastic cancers and hyperglycosylated hCG is increased in hCG-secreting malignancies. We investigated whether hCG can distinguish PtCa cancer from benign disease and add prognostic information.

DESIGN

Observational study.

METHODS

Measurement of urinary hCG (total and malignant isoforms) and serum malignant hCG in 8 subjects with PtCa and in 18 subjects with PHPT (measurement of urine in ten and serum in eight).

RESULTS

Total urinary hCG was normal in the benign PHPT control subjects (range: 0-17 fmol/mg Cr; nl<50). In the PtCa subjects, three had normal total urinary hCG levels and survived complication free for at least 2 years; three had persistently elevated total urinary hCG levels (range: 217-1986 fmol/mg Cr) and sustained hip fracture (n=3) and died (n=2) within 3 and 6 months respectively; two had a rise in total urinary hCG and had hip fracture (n=1) and died (n=2) within 4 and 10 months respectively. Elevated urinary hCG was of the malignant hyperglycosylated isoform. Serum malignant hyperglycosylated hCG values in all of the cancer patients exceeded the maximal serum malignant hCG level of the PHPT subjects with benign disease (3.77 pmol/l).

CONCLUSION

hCG, especially its hyperglycosylated isoform, might add diagnostic and prognostic information in PtCa. Further studies would help to elucidate the role of hCG as a potential tumor marker in this disease.

Évaluation de la malignité dans les tumeurs endocrines digestives : recommandations pratiques

For a long time, the assessment of malignancy risk and patient outcome in digestive endocrine tumors had to rely on sparse and mostly unconfirmed data. The 2000 WHO classification with its standardized scheme of pathologic report constitutes a framework facilitating the assessment of tumor malignancy and has been regarded to be useful for clinical purposes, providing the basis for proper patient management and for designing treatment protocols. The classification is based on a combination of pathological and clinical features with parameters specific for each organ in which the endocrine tumors originate. Three main categories are considered: 1) well differentiated endocrine tumors, further subdivided into tumors with benign and with uncertain behavior; 2) well differentiated endocrine carcinomas, low grade; and 3) poorly differentiated endocrine carcinomas, high grade. In this review the differential tumor characteristics between the above categories are summarized. The relevance of additional features as for tumor prognostication, chiefly the Ki67 proliferation index and malignancy associated genetic changes, is discussed with emphasis on the discrepancies emerging between tumors of foregut and midgut origin.