Oncoplastic secondary breast reduction

Hi everyone. This is my first post but have read many threads throughout this site. Diagnosed July 3, 2017 with IDC clinical stage II at the outer chest wall and still going through all the processes required prior to surgery which is frustrating. The process seems strange to me. Of note, My younger sister had stage III IDC BC which did not show up on mammo and she chose bilateral mastectomies.

I saw my BS initially and have no followup prior to scheduling surgery. I had an initial US-guided biopsy which prompted an MRI and then MRI-guided biopsy, geneticist appointment and then finally a PS appointment yesterday. He will talk to my BS and then they will schedule surgery.

PS suggested oncoplastic secondary breast reduction as reconstruction as I previously had reduction 20 years ago. We were so caught up in discussion during the appt that I forgot to mention the nipple-areola were free grafts instead of leaving them attached and moving them. I'm plus size and there is really nothing I can do to change that at the moment so I realize I'm not the ideal plastic surgeon candidate. I'm a C cup right now but have issues sometimes filling the entire upper cup with bras.

Perhaps I am understanding this surgery incorrectly but if they do another reduction, it seems like I will not be left with much. It's disheartening if you have had previous reduction to hear someone suggest another reduction if you can relate. Maybe it is just the technique they would use but he said the BS had said they would be taking a lot of tissue.

Anyone else out there who has a similar situation with oncoplastic secondary breast reduction technique? Because I have no followup appts prior to surgery, I feel uncertain about things. I also just had the genetic testing drawn which they said will take 3 weeks so don't really want surgery until I know those results. PS agreed with me but BS thought we should go ahead and we could go back and do madtectomy later if necessary. I don't want multiple surgeries if they can be avoided.

Thanks for your input!