I sincerely do not want to cause you more stress, but I am concerned you are being asked about "what surgery you prefer"...before even seeing the doctor 1st!!!...it's like saying "do you prefer steak or chicken?"....how can anyone make a decision like that without being given all the options and why, first?...be aware that years ago, mastectomies were the ONLY option women had but not so true today...there are still circumstances where a mast is recommended but many cases are successful with lumpectomies now..a mastectomy requires more extensive surgery and an overnite stay in the hospital, where a lump is done as an outpatient and requires less recovery time....I'm not talking you out of the mastectomy...do it if it will give you the best success for survival for the type of cancer you have...just be sure to get ALL the facts and options beforehand...don't decide that on the phone!
Many times on this site, people have advised if you are not comfortable, you may want to get a 2nd or even 3rd opinion before getting a mastectomy...I get the sense you are feeling concerned if this is the appropriate avenue, given what you know about your case...always follow your gut instinct!
Regarding size of tumor, I had 2 tumors and one was considered large (5 cm)...but my surgeon did chemo 1st where he gave me a new med called Perjeta, that actually shrunk my tumor down enough that I only had to get a lumpectomy...I would have gotten a mast if that was the best option, but even though it's got scars, I like that I still have my boob (never thought I'd be that attached to it LOL)...also it has been said a mastectomy cannot remove all breast tissue so no guarantee you never get cancer again on that side
just make sure this is the best option for you and not because this one particular surgeon thinks this is the only option...that's why I went to a breast surgeon and not a general surgeon...mine was interested in preserving the breast as well as saving my life...must be true, I'm still here and kickin"
praying you make the best choice for YOU