Prostacyclin in prostatic cancer: a better marker than bone scan or serum acid phosphatase?

Prostaglandins have been implicated in the development and spread of malignant tumours. Gas chromatography and mass spectrometry (GC-MS) analysis of prostaglandins in benign and malignant prostatic tissue showed that prostacyclin (PGI2), a prostanoid known to induce bone resorption, was the major component. PGI2 is hydrolysed to 6-oxo-PGF1 alpha. Plasma levels of 6-oxo-PGF1 alpha were measured as an index of PGI2 formation in patients with benign and malignant prostatic disease. The mean plasma 6-oxo- level in an age-matched control group was comparable to that of patients with benign prostatic hypertrophy. A significant elevation was found in patients with a TO carcinoma (P less than 0.05). Plasma 6-oxo- levels rise with advancing disease and the concentration varied with the degree of tumour differentiation. Plasma 6-oxo-levels were a more accurate monitor of disease progression than tartrate labile acid phosphatase in patients with M1 carcinoma. Persistently elevated levels were associated with a bad prognosis.