This article story does an excellent job of reporting the initial results of the Study of Tamoxifen and Raloxifene Trial (STAR) for post-menopausal women at high risk of developing breast cancer. Tamoxifen is currently the only drug with FDA approval for both treatment and prevention of breast cancer in high-risk women. The story is optimistic about new hormone therapy options for the prevention for breast cancer, but appropriately cautious about the early results of the STAR trial and use of raloxifene for chemoprevention. There is discussion that hormone therapy for the prevention of breast cancer is only for post-menopausal women at higher risk of developing the disease, and a side note which discusses who might be in this category. There is also discussion that women who have a history of blood clots and heart disease were not included in this study, as the risk of hormone therapy might exacerbate these conditions and outweigh the preventative benefit of hormone therapy for breast cancer.
The article adequately discusses the STAR trial design in which post-menopausal women at higher than average risk of developing breast cancer were randomly assigned to take tamoxifen or raloxifene (Evista) as chemoprevention for invasive breast cancer. However, the story fails to mention that only estrogen-receptor positive women should take this medication.
Because of the initial positive results of the STAR trial, namely, there were fewer uterine cancers and blood clots in the raloxifene group, the trial was unblinded at 4 years. The story does not report that these results did not reach statistical significance, or that the study was unblinded early due to these statistically non-significant results. This information was not readily available on the NCI (National Cancer Institute) website or in reports of the study, so we rated this criterion as satisfactory since balanced infomation on side effects for both tamoxifen and raloxifene are presented. The caveat provided here is important: results of this trial await further analysis and the data have yet to be published in a peer-reviewed medical journal. Clinical decisions about switching hormone medications should wait until these data are carefully reviewed. Cost comparison of the medications is provided, as well as a note that these drugs must be taken daily for 5 years.
Tamoxifen has been studied for over 30 years and has been shown to reduce the risk of breast cancer recurrence in both a breast treated for cancer, as well as the other breast. Raloxifene is currently used to prevent osteoporosis, and while it appears to have similar benefits to tamoxifen in the prevention of invasive breast cancer, it has not been studied for as long as tamoxifen, and as this articles notes, it does not appear to prevent as many cases of non-invasive breast cancers (which are more common) as tamoxifen.
The cost of treatment is provided in a side bar: raloxifene is about $75 for a month’s supply, while tamoxifen is about $100. Story notes that medication is taken daily for 5 years.
Provides relative risk reduction of chemoprevention with hormone therapy for high-risk women, however, no absolute risk reduction provided. No quantitative risks mentioned for taking hormone therapy for chemoprevention. Incomplete discussion of reduced rate of side effects in raloxifene group.
Mentions harms of hormone therapy, such as an increased risk of blood clots and uterine cancers. Notes that there were “fewer side effects” (i.e. blood clots and uterine cancers) in the raloxifene group, but does not mention that the difference in side effects was not statistically significant for uterine cancer and blood clots. This information was not readily available on the National Cancer Institute (NCI) website or in reports of the study, but we give this a “satisfactory” score because the story presents caveats on the drugs. Mentions reduction in the risk of cataracts with raloxifene, which was statistically significant. Does mention that raloxifene, like tamoxifen, has bothersome side effects such as hot flashes and vaginal discharge, which are reported as comparable and mild to moderate in the NCI press release of the initial results of this trial.
The story discusses study design and notes that results have not yet been peer-reviewed in a medical journal. Story also notes that tamoxifen protects women from DCIS (ductal carcinoma in situ) and LCIS (lobular carcinoma in situ) better than raloxifene. However, no quantitative evidence is presented on benefits or side effects of either drug, and no mention that the study was unblinded early.
Chemoprevention is for a small number of women and tamoxifen should only be offered to women with a 5-year projected risk for breast cancer of 1.6% in order to reduce their risk. The side bar is helpful, providing a clearer understanding of who might be at higher risk. Also, this medication is for women with estrogen-receptor positive breast cancer. This article does a good job of explaining that this drug is only for postmenopausal women with a greater chance of malignancy and the benefit of the drug must be weighed against the health risks for each woman.
This study was partially funded by Eli Lilly and AstraZenaca, makers of Evista and tamoxifen, though this is not mentioned. There is also no mention of whether the breast cancer expert cited from the American Cancer Society has financial ties with these drug companies.
The story does mention another chemoprevention hormone drug, tamoxifen. It also mentioned aromatase inhibitors as options being investigated for chemoprevention. Does not mention need for mammograms (screening as early detection shown to improve outcomes) in post-menopausal women at a higher risk of breast cancer. It should be noted that the results presented in this story are initial findings after 4 years of raloxifene. Tamoxifen is usually taken for 5 years and there is much more long-term clinical data on safety and efficacy for this drug. The study was unblinded early due to the improved side effect profile for raloxifene, which was not statistically significant.
The story mentions that raloxifene is currently available for use in post-menopausal women to prevent osteoporosis and that use in chemoprevention has only been in clinical trials–more data is needed prior to FDA approval for use as chemoprevention. Use as chemoprevention would be off-label and only women with an increased risk of breast cancer.
Notes that use of raloxifene (Evista) as chemoprevention is new. Evista is already approved to prevent osteoporosis.
Does not appear to be directly from a press release and there is a link for more information on study at NCI website. Breast cancer experts not affiliated with the NCI trial provide perspective in interpreting the results.