Medicine is an ever-changing science. As new research and clinical experience broadens our knowledge, changes in treatment and drug therapy are required. Knowledgeable cancer information specialists have checked with sources believed to be reliable in their efforts to provide information that is complete and generally in accord with the standards accepted at the time of publication.

However, in view of the possibility of human error or changes in medical sciences, neither the Iowa Consortium for Comprehensive Cancer Control or any other party who has been involved in the preparation or publication of this work warrants that the information contained herein is in every respect accurate or complete, and they are not responsible for any errors or omissions or for the results obtained from the use of such information. Readers are encouraged to confirm the information contained herein with other sources.