Aggressive of Her2Neu gene

I have a question on the aggressiveness of the her2neu gene...if you were diagnosed with her2+3 does that always mean that the cancer will return because someone told me that the question is not if it will return but when will it come back. I thought that you had to have positive nodes in order for the cancer to return. Thanks for all your help, in advance...hugs and praying everyday for a cure...lorraine