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Updated: Jan 2, 2026
Multiplexed Immunofluorescence Analysis and Quantification of Intratumoral PD-1+ Tim-3+ CD8+ T Cells
Published on: February 8, 2018
Association of Tumor-Infiltrating Lymphocytes with Homologous Recombination Deficiency and BRCA1/2 Status in Patients
Melinda L Telli1, Charles Chu2, Sunil S Badve3
1Stanford University School of Medicine, Stanford, California. mtelli@stanford.edu.
Purpose:
Patients with triple-negative breast cancer (TNBC) with homologous recombination deficient tumors achieve significantly higher pathologic complete response (pCR) rates when treated with neoadjuvant platinum-based therapy. Tumor-infiltrating lymphocytes (TIL) are prognostic and predictive of chemotherapy benefit in early stage TNBC. The relationship between TILs, BRCA1/2 mutation status, and homologous recombination deficiency (HRD) status in TNBC remains unclear.
Experimental Design:
We performed a pooled analysis of five phase II studies that included patients with TNBC treated with neoadjuvant platinum-based chemotherapy to evaluate the association of TILs with HRD status (Myriad Genetics) and tumor BRCA1/2 mutation status. Furthermore, the relationship between pathologic response assessed using the residual cancer burden (RCB) index and HRD status with adjustment for TILs was evaluated.
Results:
Among 161 patients, stromal TIL (sTIL) density was not significantly associated with HRD status (P = 0.107) or tumor BRCA1/2 mutation status (P = 0.391). In multivariate analyses, sTIL density [OR, 1.23; 95% confidence interval (CI), 0.94-1.61; P = 0.139] was not associated with pCR, but was associated with RCB 0/I status (OR 1.62; 95% CI, 1.20-2.28; P = 0.001). HRD was significantly associated with both pCR (OR 12.09; 95% CI, 4.11-44.29; P = 7.82 × 10-7) and RCB 0/I (OR 10.22; 95% CI, 4.11-28.75; P = 1.09 × 10-7) in these models.
Conclusions:
In patients with TNBC treated with neoadjuvant platinum-based therapy, TIL density was not significantly associated with either tumor BRCA1/2 mutation status or HRD status. In this pooled analysis, HRD and sTIL density were independently associated with treatment response, with HRD status being the strongest predictor.
