Welcome to our support group. Believe it or no you do share something in common with everyone here including myself. We all were first time users at one time or another.
Herceptin has only been FDA approved since 1998. My wife Christine received her first Herceptin in September of 1999. She is currently NED.
You can read hers and other success stories on our stories page:
http://www.her2support.org/stories.html
You may want enroll in Genentech's RegistHer program. They are amassing data from hundreds of patients for long term studies which will provide answers to your questions. But data will not be released for several years.
Well wishes,
Joe