post breast cancer surgery

My mother-n-law was diagnosed with breast cancer in late December.  She had the surgery in January where they removed the cancerous lumps and several lympthnods.  She had radiation implants done in the hollow spots where the lumps were removed.  She has had 4 rounds of Chemotherapy.  Yesterday, she went back to her doctor for a checkup and they discovered she has hard knots where the hollow pocket was after removing the lumps.  Is that normal or is there a chance cancer has already grown back in those spots?  She was told there was no way of checking to be sure until her last treatment of chemotherapy which is in 8 weeks.

Thanks,
Weisscokid  

[Cleveland Clinic]

Dear Weisscokid:  The knots in the breast could be several things; scar tissue from surgery, scar tissue from radiation implants, or possibly cancer recurrence.  You might ask the doctor what his thoughts are.   If there is cause for concern, you might ask the surgeon about a mammogram to further define the areas.  If biopsy is required, it would likely be best to pursue this when her blood counts are not compromised from the chemotherapy.