SAN ANTONIO – Temporary pretreatment with low-dose arsenic (LDA) may protect normal breast tissue during chemotherapy for breast cancer in patients undergoing breast-conserving therapy, a study presented at the 2016 San Antonio Breast Cancer Symposium (SABCS) has shown.1

Patients undergoing breast-conserving therapy typically receive chemotherapy, which may also damage healthy breast tissue leading ultimately to a negative impact on quality of life. Therefore, there is an urgent need to protect the normal breast tissue of patients opting for chemotherapy.

“More and more evidence shows that chemotherapy-induced normal tissue damage is mainly caused by the activation of p53 pathway, which is separate from the tumor suppressor pathway of p53,” said Meijun Long, MD, Breast Cancer Center, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. “Previous studies found that use of LDA could temporarily and reversibly suppress p53 activation. There are recent studies showing LDA selectively protects bone marrow and the gastrointestinal tract during cancer treatment.”


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To evaluate whether the use of temporary LDA inhibits p53 activity, researchers pretreated human breast epithelial cell lines and breast cancer cell lines with LDA or a control, followed by fluorouracil or DMSO.

In cells treated with fluorouracil, researchers observed reduced cell density, rounder cell shape, atrophied cell membranes, pyknosis of cell nuclei, and globule formation.

“LDA pretreated human epithelial breast cells showed significant growth inhibition by fluorouracil at all detected time points,” explained Dr Long. “Interestingly, LDA treatment had negligible effect in breast cancer cells.”

The findings showed that temporary LDA pretreatment selectively protected healthy breast cells from fluorouracil-induced toxicity, but it did not have an effect on tumor cells.

Reference

1. Long M, Huang Y, Liu R, et al. A p53-based strategy for protecting normal breast tissue from chemotherapy-induced damage in breast conserving therapy. Poster presented at: 2016 San Antonio Breast Cancer Symposium; December 6-10, 2016; San Antonio, TX.