Study links breast cancer resistance with timing of soy consumption

April 2, 2012

Studies exploring the relationship between soy consumption and breast cancer have been mixed, but new research introduces a new thought: Could women with breast cancer who began eating soy as an adult develop a tumor more resistant to treatment?

That's the suggestion of a new study in animal models that could provide important hints for women with who eat soy. The research from Georgetown Lombardi Comprehensive Cancer Center was reported today at the American Association for (AACR) Annual Meeting 2012.

For tumors that are sensitive to hormonal treatment (estrogen receptor and/or progesterone receptor positive), tamoxifen is often given after primary treatment to keep the cancer at bay. Unfortunately, many tumors become resistant to the tamoxifen --meaning the drug stops working and the cancer grows again.

In the new research conducted in the laboratories of Leena Hilakivi-Clarke, PhD and Robert Clarke, PhD, DSc, both professors of oncology at Georgetown Lombardi, researchers looked at the impact soy consumption might have on .

For the study, were fed soy isoflavone genistein (a estrogen-like compound in soy) at various points in their lifetime. At adulthood, all rats were exposed to a substance that triggered to develop and then given tamoxifen. The study groups were as follows: one group was never fed genistein until tamoxifen was started; a second group was fed genistein only in youth and not again until tamoxifen was started; a third group was fed genistein only as adults and continued after tamoxifen was given; and finally, a fourth group was fed genistein during youth and adulthood and continued after tamoxifen was given.

"Genistein intake in adult life which continues during tamoxifen treatment appears to make the tumors resistant to tamoxifen," explains Hilakivi-Clarke, the study's senior author. "However, if animals were fed genistein during childhood, and intake continues before and after tumors develop, the tumors are highly sensitive to the ," she explains.

"These results suggest that western women who started soy intake as adults, should stop if diagnosed with breast cancer," Clarke concludes.

The research was presented by the abstract's lead author Xiyuan Zhang, M.S. Other authors include Anni Warri, Ph.D., Idalia M. Cruz, and Katherine Cook, Ph.D.

Related Stories

Recommended for you

Study suggests colon cancer cells carry bacteria with them when they metastasize

November 24, 2017
(Medical Xpress)—A team of researchers working at Harvard University has found evidence that suggests a certain type of bacteria found in colon cancer tumors makes its way to tumors in other body parts by traveling with ...

Promising new treatment for rare pregnancy cancer leads to remission in patients

November 24, 2017
An immunotherapy drug can be used to cure women of a rare type of cancer arising from pregnancy when existing treatments have failed.

Researchers unravel novel mechanism by which tumors grow resistant to radiotherapy

November 23, 2017
A Ludwig Cancer Research study has uncovered a key mechanism by which tumors develop resistance to radiation therapy and shown how such resistance might be overcome with drugs that are currently under development. The discovery ...

African Americans face highest risk for multiple myeloma yet underrepresented in research

November 23, 2017
Though African-American men are three times more likely to be diagnosed with multiple myeloma, a type of blood cancer, most scientific research on the disease has been based on people of European descent, according to a study ...

Encouraging oxygen's assault on iron may offer new way to kill lung cancer cells

November 22, 2017
Blocking the action of a key protein frees oxygen to damage iron-dependent proteins in lung and breast cancer cells, slowing their growth and making them easier to kill. This is the implication of a study led by researchers ...

One-size treatment for blood cancer probably doesn't fit all, researchers say

November 22, 2017
Though African-American men are three times more likely to be diagnosed with a blood cancer called multiple myeloma, most scientific research on the disease has been based on people of European descent, according to a study ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.