Hi there,This is Dr Basu, experienced Internal Medicine Specialist.I am here to address your concerns and provide great service.
I understand your concern. CA 15-3 can rise due to the recent infection. Antibiotics will not affect the level though. Since you were given antibiotic, that means you had an infection. Hence this may not be suggestive of cancer recurrence. Benign breast disease also can raise CA 15-3 level. Liver disease is another common benign cause. The level should be repeated after a month to see if it is dropping towards the baseline value. Best wishes,It was my pleasure to help you today.If I have answered all your questions, Please rate my response Excellent (click on the 5th star on top).Please bookmark my profile for fast, reliable authentic answers!This is the link to my profile:http://www.justanswer.com/medical/expert-mysticdoc/