Selective cyclooxygenase-2 (COX-2) inhibitors used for preventing or regressing cancer

The current use of antineoplastic drugs in human therapy causes a substancial number of toxic or side effects which consequently lead to a reduction of the amount of drug to be administered, and in some cases to discontinuation of the therapy. A reduction of the amount of drug to be administered or discontinuation of the therapy causes an increase in primary tumour growth and/or the occurrence of tumour metastases. For this reason, the development of new anti-cancer drugs with lower side effects is necessary. This review gives a general idea about the origins of cancer and the importance of cyclooxygenase-2 (COX-2) in oncogenesis. Evidence from clinical and preclinical studies indicates that COX-2-derived prostaglandins participate in carcinogenesis, inflammation, immune response suppression, apoptosis inhibition, angiogenesis, and tumour cell invasion and metastasis. The recent anti-tumour drugs are based on tests of known selective COX-2 inhibitors and on the drawing and synthesis of new potent derivatives. Maybe, this can be the way to obtain new anti-tumour drugs with very low collateral effects. Selective COX-2 inhibitors are being mixtured with new anti-cancer drugs in order to obtain better results in the regression of cancers. Some natural products are selective COX-2 inhibitors and have anti-inflammatory and anti-cancer properties. The relevant patents are discussed.