A 48-year-old woman with T2N1M0 ER-positive, HER2-negative breast cancer undergoes neoadjuvant chemotherapy. Post-treatment imaging shows a pathological complete response (pCR). Which statement best describes the significance of pCR in this context?

• A pCR guarantees no benefit from adjuvant endocrine therapy
• B pCR is associated with improved event-free survival especially in triple-negative and HER2-positive subtypes ✓
• C pCR allows omission of breast surgery
• D pCR is defined as absence of residual tumor in the breast only, regardless of nodal status

Explanation

Pathological complete response (absence of invasive cancer in both breast and axillary nodes after neoadjuvant therapy) is a surrogate marker for improved long-term outcomes, most strongly in triple-negative and HER2-positive subtypes where biological responsiveness is highest. ER-positive luminal tumors have lower pCR rates and pCR is less predictive in this subgroup. Surgery is still mandatory after neoadjuvant therapy; pCR is confirmed on surgical specimen, not imaging alone.

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.