On Monday, the National Cancer Institute (NCI) announced early results from a trial comparing raloxifene and tamoxifen in preventing breast cancer in postmenopausal women at high risk.
The NCI announcement, and news coverage of it, left much to be desired. In most accounts, the NCI said both drugs cut the number of new cases of breast cancer in half, but women taking raloxifene experienced fewer serious side effects such as blood clots and cancer of the uterus. But half of what? They used relative risk reduction figures. Most people are better served by being told the absolute risk reduction - half of what starting point?
The National Women's Health Network (NWHN) says on its website:
"The NCI stressed the raloxifene benefit in its announcement, stating 'For many women, raloxifene’s benefits will outweigh its risks in a way that tamoxifen’s benefits do not.' NWHN is more cautious about the results of the trial, and believes that the breast cancer benefit of raloxifene may only be useful to a very small number of women."
The NWHN goes on to post: "NCI’s announcement doesn’t include much of the information that careful women and health care providers need to evaluate the overall risks and benefits of these drugs. We must also remember that the results have not yet been reviewed by experts who weren’t involved in the study (a requirement before the research can be published in a major medical journal), nor has the Food and Drug Administration (FDA) examined the records of the study to determine whether the agency will approve raloxifene for breast cancer risk reduction. ... We don’t know whether or not raloxifene, or tamoxifen for that matter, truly prevents breast cancer, or just delays it. NCI’s earlier trial of tamoxifen compared to a placebo only followed women for two years after they stopped taking their pills, not nearly long enough to know whether tamoxifen’s benefit is lasting. This trial can’t answer that question, either.
Many of the details of other benefits and risks of tamoxifen and raloxifene were not released by NCI. For example, we don’t know the specifics about how many women were able to avoid a bone fracture, how much both drugs increased the risk of stroke, and how many women died while they were part of the study."
This is the kind of analysis lacking in many news stories. Of course, for a look at how some media performed on this story, go to HealthNewsReview.org.
Posted by schwitz at April 19, 2006 09:46 AM | TrackBack