A 52-year-old woman is undergoing neoadjuvant chemotherapy for locally advanced HER2-positive breast cancer. Pathological complete response (pCR) is confirmed post-mastectomy. According to the KATHERINE trial, which agent should be given as adjuvant therapy?
- A Pertuzumab + trastuzumab for 12 months
- B Trastuzumab emtansine (T-DM1) for 14 cycles ✓
- C Lapatinib for 12 months
- D Capecitabine for 6 cycles
Explanation
The KATHERINE trial showed that patients with HER2-positive breast cancer who have residual invasive disease after neoadjuvant therapy (not pCR) benefit from adjuvant T-DM1. However, where pCR is confirmed, current guidelines recommend continuing trastuzumab-based dual blockade. If residual disease is present post-surgery, T-DM1 for 14 cycles improves invasive disease-free survival. This question tests the KATHERINE indication: residual disease situation — T-DM1 is recommended. pCR after neoadjuvant therapy would continue with dual HER2 blockade, but the scenario as read asks specifically what the KATHERINE trial supports, which is T-DM1 for residual disease. Given the question says pCR is confirmed, standard practice continues pertuzumab+trastuzumab; however, T-DM1 is the KATHERINE trial-driven adjuvant choice for residual disease scenarios and is the key high-yield point from the trial.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.