TIL（肿瘤浸润淋巴细胞）（TILs）作为接受新辅助真实世界 KEYNOTE-522 方案治疗的早期三阴性乳腺癌（TNBC）多样化患者人群中病理完全缓解（pCR）的预测标志物

We retrospectively reviewed 187 patients with early-stage TNBC at two institutions (one tertiary care, one safety-net) who completed neoadjuvant K522 treatment between 2021 and 2024. Statistical analyses included Chi-squared tests, Z-tests, and univariate logistic regression to evaluate associations between TILs, ethnicity, tumor grade, and pCR, and multivariate logistic regression to assess whether the association between dose intensity and pCR differed by the presence of TILs at baseline.

The overall pCR rate was 57%; TILs were present in 52.8% of cases. TILs were associated with a significantly higher pCR rate (70% vs. 48% without TILs; p = 0.0027). While pCR rates were similar across ethnicities, Hispanic patients with TILs had significantly higher pCR than those without (80.0% vs. 51.5%; p = 0.0254). Controlling for grade, patients with TILs were 2.442 times more likely to achieve pCR (CI: 1.310-4.553; p = 0.0050). Grade 3 tumors and node-positivity with TILs also showed statistically significant rates of pCR. Logistic regression analysis revealed a significant interaction between TIL status and immunotherapy dose intensity on pCR. While dose intensity did not influence pCR in TIL-negative patients, TIL-positive patients achieved higher pCR rates with lower dose intensity (OR = 1.54, p = 0.036).

TILs serve as a strong predictive biomarker for immunotherapy response in a real-world TNBC population. Our findings regarding Hispanic, node-positive patients, and the interaction between TIL status and dose intensity suggest that TILs could guide treatment de-escalation to reduce K522-related toxicity. Standardizing TILs reporting is critical to optimizing treatment strategies and improving outcomes in underrepresented populations.