American Association for Cancer Research

High-Impact Science in AACR Journals

The National Academy of Sciences is a private organization of scientists and engineers dedicated to the furtherance of science and its use for the general welfare. Election into the Academy is considered one of the highest honors that can be accorded to a U.S. scientist or engineer.

In April 2010, the NAS elected 72 new members and 18 foreign associates from 14 countries. Five of the inductees are AACR members:

 

The STAR P-II Trial

 

In the June 2010 issue of Cancer Prevention Research, Vogel et al. publish an update to the NSABP STAR Trial, and four leaders in the field provide Perspectives exploring the implications of the study.

Perspectives

Summary

The selective estrogen-receptor modulators (SERM) tamoxifen and raloxifene are both U.S. Food and Drug Administration–approved agents for reducing breast cancer risk but have not gained wide acceptance for prevention for a variety of reasons, as will be discussed. In this issue of Cancer Prevention Research, Vogel and colleagues present an updated analysis with an 81-month median follow-up of the Study of Tamoxifen and Raloxifene (STAR) P-2 Trial. Long-term raloxifene retained 76% of the effectiveness of tamoxifen in preventing invasive disease and grew closer to tamoxifen in preventing noninvasive disease, but with lower risk of endometrial cancer, fewer thromboembolic events, and fewer gynecologic complications.

Despite the positive results from the original STAR report and from other prevention trials, these agents are infrequently used by women at risk for breast cancer. Hortobagyi and Brown consider potential factors responsible for the lack of utilization. The authors speculate that women and physicians fear the rare adverse effects demonstrated by preliminary, underpowered European studies. They also attribute low acceptance and utilization to results from the Women’s Health Initiative showing adverse effects of hormone replacement therapy because SERMs and hormones are considered the same by the public. Furthermore, primary-care physicians may have difficulty in assessing the complex risk/benefit ratio of tamoxifen and raloxifene. Other factors suggested by the authors include misinformation, limited high-risk predictors, lack of markers, and cost.

In order to increase the use of these preventive agents, Ravdin argues that after the large investment in the definitive studies of tamoxifen and raloxifene, an investment must now be made in decision-making tools that will allow health professionals and women to understand the trials’ results and make informed decisions about SERM chemoprevention. These tools must easily provide baseline risks not only of breast cancer but also for other health problems as well as predict the change in risk that would result from tamoxifen or raloxifene treatment. Ravdin points out that tools to assist in the education, communication, and decision-making of patients and clinicians are emerging, but none yet exist for chemoprevention.

In the final Perspective article, Cuzick highlights the importance of long-term follow-up of cancer prevention trials using several cancer trials as examples. The follow-up STAR report extended the reporting period from the original median 47 months to 81 months. The updated STAR results indicate that raloxifene became less effective than tamoxifen in preventing invasive breast cancer and grew closer to tamoxifen in preventing noninvasive breast cancer. Longer follow-up also clearly establishes lower risk of endometrial cancer and fewer thromboembolic events and other gynecologic complications with raloxifene.

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