Low dose vitamin A derivative does not prevent head and neck tumors
11/24/2006 Italy staff Xagena Medicine (www.xagena.it) Taking a vitamin A derivative called Isotretinoin (Accutane/Roaccutane) did not reduce the risk of second primary tumors or improve survival in patients with stage I or II head and neck squamous cell cancers (HNSCC). In addition, current smokers had an increased risk of second primary cancers and death. HNSCCs are the fifth most common cancers and sixth leading cause of cancer related death today. In 2002, there were 600,000 new cases diagnosed worldwide. Some studies have suggested that vitamin A derivatives called retinoids may halt or even reverse growth of head and neck tumors. A clinical trial of high doses of a retinoid called isotretinoin, widely used to treat cystic acne, in patients with HNSCC found that those receiving isotretinoin developed fewer second primary tumors, particularly smoking-related tumors. However, there were substantial side effects among those who received the high-dose isotretinoin, and subsequent studies of the compound have shown mixed results. To assess the effect of lower, more tolerable doses of isotretinoin on the development of second primary tumors and survival among patients with early-stage HNSCC, Fadlo R. Khuri, of the Emory University School of Medicine in Atlanta, and colleagues conducted a randomized clinical trial of 1190 patients diagnosed with stage I or II HNSCC. Patients were randomly assigned to receive low-dose Isotretinoin (30 mg/day) or a placebo for 3 years. Researchers continued to monitor the patients for 4 or more years after treatment. This clinical trial is the largest chemoprevention study to date [...]