Women in menopause dread the sweats and flushing of hot flashes  — but for women undergoing breast cancer treatment, getting hot flashes might be a reason for optimism.

Research shows that women with early stage breast cancer who have hot flashes during treatment are less likely to see their breast cancer return or to develop new breast tumors.

Fruits, vegetables and high-fiber foods appear to help prevent breast cancer’s return.

“Hot flashes seem to provide evidence that the hormonal therapy used to deprive cancer cells of their estrogen is effective,” said Joanne Mortimer, M.D., vice chair of City of Hope’s Department of Medical Oncology & Therapeutics Research.

Scientists believe women get hot flashes because of dropping levels of the hormone estrogen, typical in menopause. Most breast cancers depend on estrogen to grow, so when breast cancer patients experience hot flashes, it may mean their tumor cells are getting starved of their needed hormone.

What can a breast cancer patient do, though, if she doesn’t get these sudden sweats?

Eating plenty of fruits, vegetables and fiber might help boost survival for these women, according to a recent study that involved Mortimer.

Between 1995 and 2000, the study followed more than 3,000 women who had survived early stage breast cancer to find out if diet could affect the chances of their cancer coming back.

Some women received information on the U.S. Department of Agriculture (USDA) diet; other women got counseling over the phone about the same basic diet, but with more fruits and vegetables and less fat. The original study found that eating more fruits and vegetables and less fat didn’t improve women’s chances of keeping cancer away.

But Mortimer’s team looked at the data again, this time looking for any links among diet, hot flashes and breast cancer risk.

They found that when they looked only at women in the study who didn’t have hot flashes, the women on the diet with more vegetables and less fat had a significantly lower risk of breast cancer recurrence or a new tumor. What’s more, the diet seemed especially to help women who had been through menopause already.

Researchers believe that eating fruit, vegetables and fiber can reduce the amount of estrogen flowing through the body. And that may make breast cancer treatments that block estrogen even more effective.

More information about dietary recommendations to reduce cancer risk is available through the American Cancer Society.