Which markers are used to monitor for recurrence after breast cancer treatment?

• A. CA 19-9 and CA 125
• B. CA 15-3 and CA 27.29
• C. HER2-neu alone
• D. ER and PR

Answer: (B)

Monitoring for recurrence after breast cancer treatment relies on serum markers that reflect breast cancer activity over time. The markers used for this purpose are CA 15-3 and CA 27.29. They can rise when the disease recurs or progresses, so tracking their levels alongside imaging and clinical exams helps detect relapse and gauge response to therapy. They’re not perfect—some recurrences occur with normal marker levels, and levels can be influenced by non-cancer factors—so they’re used as part of a broader surveillance plan, not in isolation.

CA 19-9 and CA 125 are associated more with pancreatic and ovarian cancers, respectively, and are not standard for routine breast cancer recurrence monitoring. HER2-neu is a receptor assessed on tumor tissue to guide targeted therapy, not a serum marker for checking recurrence. ER and PR refer to hormone receptor status determined from the tumor biopsy, not markers used to monitor disease recurrence.