Still struggling with the word pre-cancer after DCIS mastectomy

Ductal carcinoma insitu means cancer in the ducts. It has not yet infiltrated but at any time it can and become an enormous untreatable. It is ore invasive but not pre cancer. It is cancer. So many woman have it removed and find it has started to infiltrate. I went through chemo with women who had local infiltrating recurrence from dcis lumpetomy.  They have since had to endure chemo and bilateral mastectomy.
You considered and made your best choice based on information. Trust in this. X