Toremifene is an antiestrogen related to tamoxifen . It has some differences, however, that may make it useful against desmoid tumors and useful as a drug to reverse multi-drug resistance . It may also exert an effect on estrogen receptor negative cells along with the usual effects through estrogen receptor binding.
Tretinoin (all-trans retinoic acid) is undergoing widespread testing after it was clearly demonstrated that it induces remissions in the rare acute promyelocytic leukemia. It has become the prototype of this chemical class of vitamin A derivatives to be studied for striking antitumor actions. These actions are possibly related to inducing a malignant cell to differentiate toward a more mature and no longer dividing cell. In this way, a cancer cell may apparently change into a normal cell.
Another form of the drug is commercially available for the treatment of acne. Both drugs are generally well tolerated by mouth at lower doses. The first signs of toxicity are dry skin and sores at the corners of the mouth, followed by short-term liver malfunction. Very high doses lead to high calcium levels, headaches and increased pressure within the skull.
Many trials of the drug, either alone or in combination with other drugs such as interferon-alpha , are expected in the future. The biological actions of retinoids are just beginning to be understood and are quite striking.
Uracil-Ftorafur (UFT) is an oral preparation from Japan's Taiho Pharmaceutical Company that can result in consistent 5-fluorouracil blood levels. It is widely used in Japan for treating gastrointestinal and breast cancers. Studies are ongoing in the U.S. in combination with leucovorin .
