The drug gained fame in the '90s after studies concluded it successfully prevented cancer. But a new computer-simulated study found tamoxifen to have lifesaving benefits that are "very small or nonexistent," except in women who are at the highest levels of risk. Even then, the major side effects -- such as blood clots and uterine cancer -- can far outweigh the benefits.
Lead researcher Dr. Joy Melnikow of the University of California-Davis said, "Overall, the impact is not going to be as large as people had originally hoped." The report, which Melnikow and her collegues will publish in the Sept. 1 issue of the journal Cancer, is one of the few to analyze deaths related to tamoxifen rather than its effect on tumors. The tumors that tamoxifen has been proven to prevent are less likely to be fatal.
Dr. Michael Grant of Baylor University Medical Center in Dallas said the virtual study was not a fair assessment of tamoxifen because it made "a lot of assumptions that don't translate into real life."
According to Grant, a realistic study would be incredibly difficult because it would have to last over the course of subjects' bouts with cancer. Also, even though Grant agrees that computers are sometimes the only way calculate mortality, they are imperfect because they "put no value on not getting cancer, and not having to go through chemo," even if the impact on death alone is not remarkable.
Cancer industry critic and consumer health advocate Mike Adams reacted to the new findings by saying, "This is further evidence that the cancer industry's focus on shrinking tumors with drugs does not translate into saved lives or enhanced quality of life." He also added, "This is why the cancer industry continues to base its so-called success on the measurable shrinkage of tumors. It's the only metric where they can claim success, even as the patients are dying from cancers that are easily preventable through naturopathic care."