Special soy compounds may help in treating certain cancers, says Tulane cancer researcher Matthew Burow (top photo), shown in his laboratory along with notes from his log book (lower photo). (Photos by Paula Burch-Celentano)

A chemical produced by specially grown soybeans may successfully fight the growth of estrogen-stimulated breast and ovarian cancers, says Tulane cancer researcher Matthew Burow. Breast cancer affects one in eight adult women, half of whom will have tumors that grow in the presence of estrogen.

Burow says that medicines such as Tamoxifen, which act against estrogen, have long been used to treat these cancers. Over time, however, the tumors may become immune to the effects of the drugs and continue to grow, leaving women with fewer options for treatment. Further, the drugs that control those tumors effectively can also increase the risk of uterine cancers.

"We have been working with the USDA (U.S. Department of Agriculture) for a while to explore the potential of soy compounds," says Burow. "There appear to be two possible avenues to explore -- the impact of the compound as a medical therapy and its possible use as a dietary supplement to fight or prevent cancer."

Burow tested the compound, a phytoalexin known as glyceollin, on mice in which he had implanted estrogen-dependent ovarian and breast cancer tumors. Over time, the compound stopped further growth of the tumors by interfering with the tumor's ability to respond to estrogen. According to Burow, the finding is significant because of the lack of effective therapies available to women with advanced breast or ovarian cancer. Unlike some of the available therapies, the glyceollins did not stimulate uterine growth, a side effect associated with increased risk of endometrial cancer.

The results of the research were published in the December 2006 issue of Clinical Cancer Research.

Burow has collaborated in the past with the U. S. Department of Agriculture and other institutions to fully understand the potential of glyceollins. In related research in primates at Wake Forest University, Burow and collaborators demonstrated that a diet rich in glyceollins also could help fight breast cancer.

Burow cautions that glyceollins are not found in most soy products, such as tofu, on the market today.

"The soy beans have to be stressed while they are growing in order to produce the glyceollins. It requires a specialized growing technique," Burow explains.

Burow worked on the research in collaboration with faculty at the Tulane Cancer Center and the Center for Bioenvironmental Research. Co-authors of the article include Tulane researchers Virgilo A. Salvo, Stephen M. Boue, Juan P. Fonseca, Steven Elliott, Bridgette Collins-Burow, Sudesh K. Srivastav, Barbara Beckman and John McLachlan.

Burow, an assistant professor in the hematology and medical oncology section at the Tulane University School of Medicine, was one of six cancer researchers honored for his work at the Mauvernay Research Excellence Seminar in December.