Low-Calorie Diet Helps Prevent Aggressive Breast Cancer from Spreading

Reducing the number of calories in diet could slow the growth of deadly breast cancer.

A new study conducted by researchers at the Thomas Jefferson University found the mechanism that reduces cancer metastasis in women suffering from triple negative breast cancer. Cancer metastasis is the spreading of the tumor to other parts of the body.

Researchers said that restricting calories in diet along with radiation treatment prevents cancer from spreading.

"The diet turned on an epigenetic program that protected mice from metastatic disease," said senior author Nicole Simone, M.D., an associate professor in the department of Radiation Oncology at Thomas Jefferson University.

Dr. Simone and colleagues had earlier found that reducing daily calorie intake increased the efficiency of radiation treatment. In the present study, researchers wanted to know what biological pathways were linking metabolism and breast cancer growth.

According to researchers, a low-calorie diet along with radiation treatment reduces the activity of certain microRNAs and promotes production of proteins that maintain extracellular matrix.

"Calorie restriction promotes epigenetic changes in the breast tissue that keep the extracellular matrix strong," explained Dr. Simone. "A strong matrix creates a sort of cage around the tumor, making it more difficult for cancer cells to escape and spread to new sites in the body."

The study was conducted on mice models that had triple negative cancer. When these mice were fed 30 percent less calories than the usual intake, their cells produced fewer microRNAs 17 and 20 (miR 17/20). These microRNAs are associated with triple negative cancer spread.

Women with breast cancer often tend to put on weight during treatment as use of hormones and steroids during therapy alters patients' metabolism. In fact, gaining weight during therapies makes standard care less effective. "That's why it's important to look at metabolism when treating women with cancer," said Dr. Simone.

The research is also important because it provides scientists with a new molecular target to fight triple negative breast cancer. However, researchers said that it is highly unlikely that medication could be as effective as diet control in these patients.

The study was funded by NCI Cancer Center Support Grant P30-CA56036 for the Kimmel Cancer Center and is published in the journal Breast Cancer Research and Treatment.

Some studies associate calorie restriction with longevity. However, there is still debate about whether or not fewer calories help people live longer.