Molecular Phenotypes in BC May Differ Between Primary Tumor and Sites of Recurrence
 

This is a Medscape article, and may require registration (free) to access:

http://www.medscape.com/viewarticle/575746

Of particular interest:

"Among the 34 regional/distant relapses:

• 11 changed from ER/PR positive to ER/PR negative
• 14 changed from ER/PR negative to ER/PR positive
• 3 changed from HER2 negative to HER2 positive
• 6 changed from HER2 positive to HER2 negative."

Hopeful