A budget crunch has delayed and could scuttle a major U.S. cancer-prevention trial set to begin in April. The $100 million experiment aims to compare a new drug, letrozole, to older pills for preventing breast cancer in women after menopause.
The trial, known as STELLAR, asks a specific question: Does letrozole, a drug in the new aromatase inhibitor (AI) class, work better as a preventative for postmenopausal women at high risk for breast cancer than an older drug, raloxifene? Based on cancer treatment results, many think that it will have milder side effects and provide better protection.
The National Cancer Institute (NCI) endorsed the project on 22 January, after 18 months of reviews, but a day later, NCI Director John Niederhuber flagged it for an intense review, to take place on 23 March. Niederhuber told The Cancer Letter, which first reported this decision, that NCI programs were under "a great deal of stress" and that some NCI grantees had "strong feelings" that the STELLAR proposal "was not good science" and not a good use of funds. NCI notes that the trial "would cost approximately $100 million, would involve about 13,000 women, and require at least 10 years before results would be available."
The price tag may not be the only issue. Paul Goss, director of breast cancer research at Harvard's Massachusetts General Hospital in Boston, says people have raised questions about the trial's value. He notes, for example, that two other big trials of AI drugs--one led by a clinical group at the National Cancer Institute of Canada, which he chairs, and another funded by the charity Cancer Research UK--are already under way. Both are placebo-controlled and can get by with relatively small enrollments (4000 to 6000). In contrast, Goss says, STELLAR will need to enroll 13,000 women to find subtle differences between two active drugs. This means STELLAR will cost more and deliver results long after the others. Goss says that STELLAR's head-to-head comparison would give a more definitive reading on the effects of each drug, but he questions whether the results would be available soon enough to affect clinical practice.
Niederhuber's decision has upset the center that designed the trial, the National Surgical Adjuvant Breast and Bowel Project (NSABP) in Pittsburgh, Pennsylvania. It suggests that cancer prevention is being pushed into "second class," says oncologist D. Lawrence Wickerham, NSABP's associate chair.
For a more detailed analysis of the decision and its effects on other clinical trials, stay tuned for the 16 March issue of Science.