Prostacyclin and thromboxane in benign and malignant breast tumours.

6-keto-PGF1 alpha and thromboxane B2 were determined by radioimmunoassay in 37 extracts of breast carcinomata, 8 fibroadenomata, 12 sclerocystic-disease specimens and 51 normal breast tissues. More prostanoids were extracted from carcinomata than from normal specimens, fibroadenomata or sclerocystic-disease tissues (P less than 0.05). The 6-keto-PGF1 alpha/TXB2 ratio was higher in carcinomata than in normal tissues and fibroadenomata (P less than 0.05) but was not significantly different from the ratio in sclerocystic disease. The prostaglandin levels and the 6-keto-PGF1 alpha/TXB2 ratios from carcinomata did not correlate significantly with age, tumour size, differentiation, lymph node status, nuclear-cytoplasmic ratio, host cell reaction, mast cells, necrosis, elastosis, fibrosis or blood vessel density. Lower nuclear density was associated with lower 6-keto-PGF1 alpha/TXB2 ratios (P = 0.01) whereas the latter value was higher when infiltration was lower (P = 0.03). There was a positive correlation between mitotic index and the 6-keto-PGF1 alpha/TXB2 ratio (P = 0.04). Cumulation of variables revealed lower prostanoid ratios in tumours greater than 2 cm without lymph node metastasis then tumours less than 2 cm with lymph node metastasis (P = 0.04). A first follow-up (14 months) showed a higher 6-keto-PGF1 alpha/TXB2 ratio in patients who developed metastasis (P = 0.04). Our study does not confirm the hypothesis that high prostacyclin levels are a good prognostic index in breast cancer.