Cyclooxygenase inhibitors are potent sensitizers of prostate tumours to hyperthermia and radiation

It has previously been demonstrated that hyperthermia can activate prostagl andin synthesis and that prostaglandins are protective against hyperthermia . This study examined the use of inhibitors of prostaglandin synthesis on t he response of prostate tumours to hyperthermia. The non-steroidal anti-inf lammatory drugs (NSAID) ibuprofen and sulindac, known cyclooxygenase inhibi tors that inhibit prostaglandin production, were effective hyperthermia sen sitizers and augmented growth delay of DU-145 and PC-3 prostate tumours to combined radiation and hyperthermia treatment protocols. Pre-treatment of m ice with ibuprofen and sulindac at hyperthermia sensitizing doses resulted in significant (p < 0.01) inhibition of hyperthemia-induced serum prostagla ndin E-2. These findings indicate that NSAID may have both sensitizing effe cts on prostate tumour growth and may function by inhibiting prostaglandin synthesis.