Nonstandard abbreviations: HPV, human papillomavirus; FAP, familial adenomatous polyposis; AK, actinic keratosis; PCPT, Prostate Cancer Prevention Trial; SELECT, Selenium and Vitamin E Cancer Prevention Trial; BCPT
, Breast Cancer Prevention Trial; CARET, Beta-Carotene and Retinol Efficacy Trial; ATBC, Alpha-Tocopherol, Beta-Carotene Cancer Prevention (trial); NSAID, nonsteroidal anti-inflammatory drug; FDA, US Food and Drug Administration; STAR, Study of Tamoxifen against Raloxifene; SERM, selective estrogen receptor-modulating agent; BCG, bacille Calmette-Guerin; DFMO, [alpha]-difluoromethylornithine (eflornithine).
Two secondary endpoints of the BCPT are worthy of consideration:
Overall, invasive cancers other than those of the breast and uterus occurred at the same rate in the tamoxifen and placebo groups of the BCPT. The RR of death from any cause was 0.81 (95% CI, 0.56-1.16).
Based on the results of the BCPT, the US Food and Drug Administration (FDA) approved tamoxifen in October 1998 for the primary prevention of breast cancer in women who are at high risk of the disease.
You are able to reassure her that, as the BCPT demonstrated, tamoxifen should not increase the risk of uterine cancer, DVT, or pulmonary embolism in a woman her age.
's recognition of the potential of tamoxifen is only the beginning -- improved forms of tamoxifen or "smart estrogens" are on the way, soy constituents are a possibility, and much more is in the works.
These results contradict those found in the BCPT
that demonstrated a protective effect of tamoxifen in higher-risk patients.
The National Cancer Institute, which supported the BCPT, responded to the European reports with an announcement that confidence in tamoxifen's ability to reduce breast cancer in at-risk women "remains firm."
The NCI was quick to point out that with more than 13,000 subjects and 329 cases of breast cancer, the BCPT's results were statistically more reliable than those of either European trial.
Although the higher incidence of breast cancer and the larger study population of the BCPT "clearly provide a greater opportunity to demonstrate an effect" of tamoxifen, those factors could not account for all of the difference between the American and European study results.