Google avastin (Bevacizumab), check the national library of medicine/NIH site - www.nlm.nih.gov. You can read about the side effects there, and yes, voice changes is listed. You can also read the warning at the top of the page for more serious side effects.
It is an antiangiogenic drug (inhibits new blood vessel formation) and can affect wound healing among other things. I think there is a push by the manufacturer to get it used for more types of cancer than what it was originally approved for.
I know a patient who just stopped using it in a clinical trial due to serious urinary complications she developed plus she didn't like the nasal septum perforation it caused, and a surgery wound was healing oddly. I know another patient that, to my knowledge, has not had any side effects like that.
I hope the information on the nlm.nih site helps you with any questions you may have.