Growth of an implanted fibrosarcoma in rats is associated with high levels of plasma prostaglandin-E2 and thromboxane-B2.

Growth of BN175, a malignant fibrosarcoma, was correlated with high plasma TXB2 and PGE2 levels. This statistically significant increase was first detected 17 days after inoculation of the tumor, at which time the tumors were 20 mms in diameter. A further increase in tumor size was associated with still higher PGE2 and TXB2 values. At the same time, progressive alterations in platelet function, as measured by ADP-induced platelet aggregation, were observed. 6-keto-PGF1 alpha levels remained normal throughout the whole experiment. It was concluded that tumor growth was associated with changes in PG synthesis and platelet function, although it remains unclear whether these changes were caused by some host immunological response towards the tumor or were predominantly the result of tumor PG-synthesis.