Is Relapsing Of Breast Cancer Possible?

i had multifocal breast cancer in rights breast was her+, er+, pr+, and 5 nodes out of 11 affected. I had a mastectemy and had herceptin for a year. I am currently taking tamoxofin and am due to have my ovaries out in feb. I am also BRCA1 carrier. Is there a strong chance that the cancer will come back again?