There is no right or wrong answer to this...each of us has to make the decision that is right for us. I had a bilateral mastectomy in April this year. That the left had to go was a given, but the right had shown signs of "abnormal geography". I was given the choice of biopsies, further scans and ra ra ra but I asked to have it removed too. Number of factors here. I'm 59 and, lets be honest, gravity, age , pregnancies and breastfeeding had taken their toll. My nipples didn't gaze cheerfully above the horizon any more, but looked rather forlornly towards the ground. I would have been very lopsided (having been a 18D), but most importantly, for me was the fear and stress of the right side going bad. I said to my surgeon, after she had gone through all the standard statistics about the second breast, that I felt as unsettled as if I was told that a registered sex offender lived next door to me. No matter how many assurances I was given about how this person would be closely monitored, ankle bracelets tracking his movements, weekly check in with his parole officer and so on, and the fact that I would probably, statistically, be safer as he was a known potential threat, rather than Joe Soap who could be more dangerous, but was off the radar, I still would not live there. I would move, but that's just me. As it happened, the post mastectomy pathology showed Atypical Ductal Hyperplasia as well as columnar cell changes in that suss right breast. Not cancerous or even technically pre cancerous, but abnormal, and would have needed very close monitoring. Not for me.