Hot flashes might be the bane of menopause — but for women undergoing breast cancer treatment, they actually may hint that their therapy is working. What can a breast cancer patient do, though, if she stays free of the sudden sweats?
New findings from a dietary intervention study show that eating plenty of fruits, vegetables and fiber might help boost survival for these women.
|Joanne Mortimer (Photo by Walter Urie)|
Joanne Mortimer, M.D., vice chair of the Department of Medical Oncology & Therapeutics Research, was senior author on the recent Journal of Clinical Oncology study called “Influence of High Vegetable, Fruit and Fiber Dietary Pattern on Breast Cancer Prognosis by Initial Hot Flash Reporting: The Women’s Healthy Eating and Living (WHEL) Trial.” The study was led by University of California, San Diego (UCSD) researchers.
As Mortimer explained, research has shown that women with early stage breast cancer who experience hot flashes during treatment have lower rates of breast cancer recurrences or new breast cancers than those who do not experience hot flashes.
“Hot flashes seem to provide evidence that the hormonal therapy used to deprive cancer cells of their estrogen is effective,” Mortimer said. “This study shows that hot flashes are associated with a better outcome in women on a regular diet. In women who did not experience hot flashes, eating a high-fiber, low-calorie diet resulted in the same decrease in risk as women who experienced hot flashes.”
Between 1995 and 2000, the WHEL study followed more than 3,000 women who had survived early stage breast cancer to examine whether diet could influence risk of cancer recurrence.
One group of women received information on the diet recommended by the United States Department of Agriculture (USDA), which includes five fruits and vegetables a day. The second group received telephone counseling on the same basic diet, but with more fruits and vegetables and less fat.
The original study revealed that diet made no overall difference in risk of breast cancer recurrence in either group. Mortimer wondered, though, if WHEL study data might reveal any links among diet, hot flashes and breast cancer risk.
About 30 percent of the original participants on the WHEL study reported experiencing no hot flashes when they enrolled. Of that 30 percent, 453 women were in the basic USDA diet group and 447 were in the counseling and special “intervention” diet group. The research team found that those on the intervention diet had a significantly lower risk of developing a recurrence of breast cancer or a new tumor: cancer reappeared in 16 percent of them, lower than the nearly 24 percent in the USDA diet group. Women who had been through menopause had an even greater reduction in risk.
Researchers believe eating fruits, vegetables and fiber may reduce circulating estrogen levels in the body. A lack of hot flashes is associated with higher estrogen levels, and most breast cancers depend on estrogen to grow.
“We have often used side effects of chemotherapy to determine if the correct dose of a drug is being given, and side effects of some drugs help predict the effectiveness of the treatment,” said Mortimer. “While we have not used side effects from hormonal therapy to predict for benefit, this study suggests that more research should be conducted to understand how hot flashes are associated with different treatment options.”
John Pierce, Ph.D., at UCSD is principal investigator of the WHEL Study Group, which also includes researchers from Stanford University, University of Arizona, M.D. Anderson Cancer Center, University of California, San Diego, University of California, Davis, and Kaiser Permanente facilities. The paper appeared in the Jan. 20 issue of the Journal of Clinical Oncology.