My mother who has had surgery and radiation for oral cancer over a year ago was given a pet scan a couple of weeks ago as a precaution. There was something suspicious in her chest so the PET was followed by a CT scan. Now her doctor is ordering a Fine needle biopsy. She is 80 years old, takes 1 low dose aspirin a day and meds for high blood pressure. She was told the biopsy can't be done until she has stopped taking aspirin for a week. What is the reason for that does anyone know? Is it because there is a danger of bleeding with the biopsy and aspirin is a blood thinner?