Dr Lang on Real-World Outcomes With the KEYNOTE-522 Regimen in Early-Stage TNBC

“We [noted that] 80% of patients could have been eligible for breast-conserving surgery, yet a small fraction [ultimately] went forward with [breast-conserving surgery] and [many] instead opted for mastectomy. [This finding presents] an opportunity to reconsider practice for our patients.”

Julie Lang, MD, chief, Breast Surgery, Lerner Research Institute; co-leader, Breast Cancer Program, Cleveland Clinic, discusses findings from a real-world, retrospective study evaluating the effect of the neoadjuvant KEYNOTE-522 trial (NCT03036488) regimen (pembrolizumab [Keytruda] plus chemotherapy) on pathologic complete response (pCR) rates and subsequent surgical decision-making in patients with early-stage triple-negative breast cancer (TNBC).

The study retrospectively analyzed 240 patients with TNBC treated between 2019 and 2022, comparing outcomes between those who received the KEYNOTE-522 regimen (n = 86) and those who received standard chemotherapy (n = 154). Results demonstrated a significantly higher pCR rate in the KEYNOTE-522 cohort compared with the control group, at 59.3% vs 33.1%, respectively (P = .001).

However, the rate of breast conservation therapy did not differ between groups, at 32.1% vs 33.1% in the investigational and control arms, respectively (P = .47), highlighting a gap between clinical response and surgical decision-making. Notably, axillary lymph node dissection was required significantly less often in the KEYNOTE-522 cohort compared with the control group, at 25.6% vs 39.6%, respectively (P = .03), indicating that neoadjuvant pembrolizumab may reduce the need for extensive nodal surgery.

Lang notes that approximately 80% of patients were candidates for breast conservation, yet many still opted for mastectomy. These findings highlight a discrepancy between clinical tumor response and surgical decision-making, suggesting that factors beyond tumor biology, such as patient preference and physician recommendation, may influence surgical choices. Given the observed real-world pCR rates of approximately 60%, Lang explains that there is an opportunity to reassess the role of neoadjuvant therapy in guiding surgical planning and to better counsel patients on their eligibility for breast conservation.