breast cancer

[graydi]

If breast cancer returns 22 years after having had carcinoma situ which involved no therapy, what are the chances that the reoccurring cancer is related to the first cancer or is a new cancer??

[Cleveland Clinic]

Dear graydi, Having had a prior history of breast cancer increases the risk for development of future breast cancers.  Whether a new cancer is a recurrence or a new primary cancer might be difficult to distinguish.  Comparison of the location of the cancers, as well as pathologic features of the biopsy might shed light on the situation.  

[japdip]

I'm not sure what you mean by "no therapy" .... if the cancer is in the breast it could be either one ... a recurrance or another primary cancer.