No one can tell you which op to go for, but I had my first WLE in early October, the margins weren't clear so I had a further excision a few weeks later and the histology showed that to have clear margins. I wasn't offered a mastectomy, so I didn't have to make a decision like you, but I would therefore speak to your CNS and ask why are they offering a mastectomy if a further excision would potentially be sufficient.  It may be that they are unsure if they will get clearance with a further excision, but if there is the potential you could keep your breast you may feel it is worth the gamble. Of course then you risk another close margin and have to go for the mastectomy anyway, which like you say is a lot longer recovery time.  I didn't find my surgery to be traumatic either time, so I may have decided to go for the WLE on the basis that if it didn't work out it would only add on a few weeks to overall recovery, but if it did I'd get to keep my breast. Okay it's now a bit scarred, but I tell my Hubbie the scar is just its smiley face because it's glad to still be here! I'm not sure if that is of any help, but I think it's a very personal decision, but there is no right or wrong, just what's right for you. Good luck. Xx