COX-2 inhibitors and breast cancer.

The cyclooxygenase ( COX ) -2 inhibitor celecoxib was recently approved in the USA for the prevention of polyp formation in familial adenomatous polyposis, a defined premalignant condition for colorectal cancer. The potential value of COX inhibitors in similar roles for other malignancies, particularly breast cancer, is therefore currently under intense scrutiny. Use of these medications in chemoprevention or treatment would represent a radical departure from established regimens because these drugs are readily accessible, inexpensive, and generally well-tolerated. Epidemiological investigations of long-term non-steroidal anti-inflammatory drug (NSAID) use have given encouraging indications of a small, but significant protective effect against breast cancer. A recent meta-analysis of 14 studies found a risk reduction of around 18%. 1 A subsequent large case-control study has confirmed this approximate level of protection, and also found that risk reduction occurred with NSAID use for any duration, with strongest effect for use lasting >8 years. 2