Honestly for smaller lesions a lumpectomy with radiotherapy the outcome is the same as mastectomy. And these days not all cancers are treated with radiotherapy either..and yes, the surgeon would have suggested if he thought it was the better option.
People believe mastectomy elimates metasteses risk...but sadly the stats do not support that. ..the risk is the same for both.
I chose mastectomy because I wanted to avoid radiotherspy (i live 500k from where it could be done) and my tumour wasn't seen in the mammogram so I was concerned if another or local recurrence happened it would not be found. I knew the stats were pretty much equal.