The National Cancer Institute (NCI) has decided to cancel one of the largest US cancer prevention trials ever planned. The STELLAR (Study to Evaluate Letrozole and Raloxifene) trial would have compared the estrogen-blocking drugs letrozole and raloxifene in nearly 13 000 postmenopausal women at high risk for breast cancer.
The trial had been approved by several NCI committees. But in January, NCI Director John Niederhuber called for a new review of the study to examine whether the costly trial would provide sufficiently valuable information to justify its $100 million price tag.
Recently, a subcommittee of the NCI's National Cancer Advisory Board stated that it could not offer strong endorsement for funding the trial. Several concerns had been raised, including whether such long-term adverse effects as a heightened risk of osteoporosis and myocardial infarction would prevent the clinical use of letrozole.
