Prognostic significance of plasma prostaglandin E concentration in patients with head and neck cancer

Plasma prostaglandin E (PGE) levels were determined by radioimmunoassay in 53 patients with various stages (II, III, and IV) of hypopharyngeal and laryngeal squamous cell carcinoma, in 12 non-cancer patients and in 10 healthy volunteers. The mean PGE concentration was somewhat higher in non-cancer patients (mean +/- SD = 34.6 +/- 5.37 pg/ml) than in healthy subjects (28.1 +/- 4.96 pg/ml). In spite of a high data variability, the mean preoperative PGE levels in cancer patients were proportional to the stage of the disease and higher than in non-cancer patients (41.2 +/- 19.7 pg/ml, 52.8 +/- 26.7 pg/ml and 82.0 +/- 34.9 pg/ml in stages II, III and IV respectively). The mean plasma PGE concentration significantly decreased for all tumour stages 15-30 days after surgical removal of the tumour, but rose again in some patients within 6-18 months after surgery. The incidence of tumour recurrences 6 and 18 months after surgery was significantly higher in patients with an increased preoperative PGE level (greater than 43.3 pg/ml) than in those patients with a PGE level within the normal range (less than 43.3 pg/ml). The mortality was also higher in the former group, but the difference did not reach the level of significance. Similarly, the mean preoperative and most postoperative concentrations of PGE were significantly higher in patients in whom tumour recurred within 18 months than in tumour-free patients.