What's So Unusual?

My oncologist says that my case is "unusual."  First dx in 1983 with invastive ductal carcinoma, 1 positive node.  Treated with lumpectomy, chemo, rads and tamox.  Local recurrence 2 months ago with 2.5 cm tumor in same breast, same spot.  CT scans of chest, pelvis and abdomen and bone scans are all clear.  Had total mastectomy 3 weeks ago (lymph nodes previously removed at time of first dx).  Grade 2, ER+/PR-, same as with first dx.  HER2 negative. Will be having 4 cycles of AC chemo plus Arimidex or Femara.  My doctors are convinced that this is a true recurrence of the first cancer and not a new primary, although they say they cannot prove it. Is this in fact an unusual case and if so, what are the factors that make it unusual?

[CCF-RN,MSN-rf]

Dear deelee:  Although I have known several people to have