Arsenic used for centuries to treat hematological malignancies is still used in cancer patients.

All forms of arsenic are a serious risk to human health. The arsenic is a hazardous substance and also classified as carcinogenic. Arsenic makes arsenic trioxide with concentrated sulfuric acid. Arsenic has been used in Manchuria (Asia) 2000 years ago, it was only first reported as a treatment for leukemia in the Western literature in 1878.; it later became a popular treatment for chronic myeloid leukemia in 1930. The compound arsenic trioxide has been under investigation in China as an anticancer treatment since 1970. Chinese investigators first reported responses to intravenous arsenic trioxide in patients with acute pro-myelocytic leukemia (APL) in 1992. Arsenic trioxide is approved and used to treat APL. More specifically, this medication is given to patients who have not responded to a different initial treatment, or whose cancer has recurred. This medication is given has an intravenous injection. The injections usually take 1 to 2 hours, but may be given more gradually if side effects occur during the infusion. Arsenic trioxide is usually given once a day for several consecutive days.