Nephrogenous cyclic AMP in primary hepatocellular carcinoma patients with or without hypercalcaemia.
OBJECTIVE
To study the relationship between the excretion of nephrogenous cyclic AMP (NcAMP) and other blood and urine parameters as an index of PTH-like activity in patients with primary hepatocellular carcinoma.


METHODS
After overnight fast, a double voided urine and a blood sample were collected from each subject for determination of various analytes and results compared between various groups.


METHODS
Fifty-five consecutive untreated patients with primary hepatocellular carcinoma, 14 healthy controls and eight patients with cirrhosis only.


METHODS
Serum calcium, phosphate, alkaline phosphatase, albumin, creatinine and urinary calcium, creatinine and hydroxyproline were measured by routine methods. cAMP was measured in plasma and urine by a radioimmunoassay (Diagnostic Products Corporation) and PTH measured in serum by an immunoradiometric assay (Nichols Institute). TmP/GFR, NcAMP etc. were calculated according to various published methods.


RESULTS
Four out of 55 patients (7%) with primary hepatocellular carcinoma had hypercalcaemia. These four patients had significantly lower (P less than 0.05) phosphate, PTH and TmP/GFR and elevated NcAMP (P less than 0.001) compared with normocalcaemic hepatocellular carcinoma and cirrhotic patients, and healthy controls. The excretion of hydroxyproline and calcium was significantly elevated (P less than 0.001) in the hypercalcaemic patients. Bone resorption was found to be the major cause of hypercalcaemia in three of the four hypercalcaemic patients. Fifteen hepatocellular carcinoma patients (29%) with normocalcaemia had suppressed PTH.


CONCLUSIONS
We conclude that a PTH-like humoral factor such as PTH related peptide is the cause of hypercalcaemia in patients with primary hepatocellular carcinoma, and that in some normocalcaemic patients with this tumour PTH is suppressed.
Panesar
N S
NS
Department of Chemical Pathology, Chinese University of Hong Kong.
Au
K M
KM
Leung
N W
NW
Shek
C C
CC
Swaminathan
R
R
D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000652:urine*; D000242:Cyclic AMP / Q000652:urine*; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000150:complications / Q000652:urine*; D008103:Liver Cirrhosis / Q000652:urine; D008113:Liver Neoplasms / Q000150:complications / Q000652:urine*; D008297:Male; D008875:Middle Aged; D015995:Prevalence
D000242:Cyclic AMP