Arizona Cancer Center Involved in Study That Shows

Low-Fat Diet May Lower Risk of Breast Cancer Recurrence

From:  Donna Breckenridge, (520) 626-2277                                               May 18, 2005

Researchers from the Women’s Intervention Nutrition (WIN) Study have found for the first time that a dietary intervention to reduce fat intake improves relapse-free survival by 24 percent in postmenopausal women who previously were treated for early-stage breast cancer, compared with women following their usual diet. The women in the study had all undergone surgery to remove their tumors and were receiving standard follow-up care.
 
The Arizona Cancer Center at The University of Arizona ranked third in overall recruitment of study participants for the WINS study among 37 sites nationally. Locally, 166 women participated in this study of more than 2,500 breast cancer survivors, a study that was conducted over a 10-year period.
 
“Through the efforts of our participants, this study has revealed that lowering dietary fat intake can have a favorable effect on breast cancer outcome,” said Cynthia A. Thomson, PhD, RD, UA assistant professor of nutritional sciences, public health and medicine and a member of the Arizona Cancer Center.  Dr. Thomson is one of the authors of the study abstract, which was presented May 16 at the annual meeting of the American Society of Clinical Oncology in Orlando, Fla.
 
The study’s lead author is Rowan T. Chlebowski, MD, PhD, a medical oncologist at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center. Arizona Cancer Center Director David S. Alberts, MD, also was involved in the WINS study during its inception and the early implementation phase.
 
“The Arizona Cancer Center is proud that it entered the third-highest number of women into this ground-breaking study,” Dr. Alberts said.  “The study results give encouragement to women, especially those whose tumors are estrogen-receptor negative, that they can do something themselves on a daily basis to reduce their risk of experiencing a relapse.  Diet and physical activity modification will prove increasingly important in the control of this devastating disease.”
 
The U.S.-based study was a prospective randomized phase III trial of patients from 36 states.  Researchers compared the incidence of breast cancer recurrence – including local/regional and distant recurrences and any new cancers in the opposite breast – between 975 postmenopausal women with early-stage breast cancer who consumed a low-fat diet (averaging 33.3 grams of fat daily) and 1,462 early-stage breast cancer patients who followed a standard diet (averaging 51.3 grams of fat daily). The women on the low-fat diet also received eight biweekly nutrition counseling sessions with registered dietitians, as well as ongoing counseling every three months.  The study began in 1994, enrolling patients ages 48 to 79.  Results were reported after a median of five years of follow-up.
 
At the end of the follow-up period, 9.8 percent of the women on the low-fat diet experienced a recurrence of their cancer, compared with 12.4 percent of those on the standard diet.  The risk reduction was even greater for women with estrogen receptor-negative cancers, which is considered a marker for poorer prognosis; these women on the low-fat diet had a 42 percent lower risk of recurrence than those following a standard diet.  However, since estrogen-negative breast cancers were less common than estrogen receptor-positive cancers, this part of the analysis should be considered exploratory since the number of recurrences was small in comparison to the comparison of recurrence in all participants.
 
“This is the first well-designed dietary intervention trial to test the relationship between a low-fat diet and breast cancer recurrence,” said Dr. Thomson.  “Our participants made the difference!  It was their decision to participate and commitment to making significant and long-lasting changes in their eating pattern that allowed us to test this important hypothesis. The Arizona Cancer Center is participating in another dietary intervention study, the Women’s Health Eating and Living (WHEL) Study, which will be completed in 2007 and should provide further information to advance our understanding of the relationship between diet and breast cancer recurrence.”
 
The Arizona Cancer Center is a National Cancer Institute-designated comprehensive cancer center at The University of Arizona Health Sciences Center in Tucson. For more information, go to www.azcc.arizona.edu.

 

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Susan Guthrie
Senior Public Affairs Coordinator
University of Arizona, College of Medicine
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