While the use of arsenic to treat acute promyelocytic leukemia (APL) is not new, important discoveries about its application and efficacy are currently being made. A recent phase III clinical trial conducted by the National Cancer Institute has revealed that arsenic can help maintain remissions in this dangerous bone marrow malignancy.

“If you have something that will take away the potential toxicity and the potential real harm of high doses of anthracycline (chemotherapy), why not do it,” asks Samuel Waxman, who early on saw the effectiveness for arsenic in treating APL after reading several Chinese studies.

SWCRF researchers in Shanghai have been collaborating with others for twenty years to show that arsenic is involved with the destruction of the PLM-RARa oncoprotein characteristic of APL, and now there is also evidence that arsenic trioxide is also linked to programmed cell death of abnormal promyelocytic white cells.

Says Dr. Waxman, “These cells are particularly sensitive to arsenic-induced apoptosis (programmed death). Secondly, they are undergoing differentiation, so you are getting a double hit from the same drug. Thirdly, it is very well tolerated in the doses given.”

In the recent randomized trial of 61 APL patients Zhu Chen, MD, PhD., and others at Shanghai Second Medical University, clinical remission rates exceeded 90%, but with fewer side effects and more sustained remissions for patients receiving combined arsenic and chemotherapy. This was reported in the Proceedings of the National Academy of Sciences.

“Chinese Folk Treatment Reveals Power of Arsenic To Treat Cancer, New Studies Under Way” by Karen Hede. Journal of the National Cancer Institute, Oxford University Press © 2007.
http://jnci.oxfordjournals.org/cgi/content/full/99/9/667