Plasma prostaglandins in lung cancer.

Plasma levels of three stable prostaglandin (PG) metabolites were measured in 29 patients with lung cancer. The mean level of 6-keto-PGF1 alpha, the hydrolysis product of prostacyclin, was significantly elevated in cancer patients compared to a control group with non-malignant respiratory disorders, although an overlap in values between the groups was seen. Levels correlated inversely with survival and showed a significant fall in 14 patients with tumour regression. The mean level of 11-deoxy-3,14-dihydro-15-keto-11,16-cyclo-prostaglandin E2 was also significantly elevated in cancer patients, but did not correlate with tumour response. 13,14-Dihydro-15-keto prostaglandin F2 alpha levels did not differ in lung cancer patients and controls. Contrary to previous reports we could not support a role for the metabolites of PGE2 and PGF2 alpha as tumour markers in lung cancer but plasma 6-keto-PGF1 alpha should be further evaluated in this regard.