Tumor-Infiltrating Lymphocytes Refine Outcomes in Triple-Negative Breast Cancer Treated with Anthracycline-Free Neoadjuvant Chemotherapy.

PURPOSE: Stromal tumor-infiltrating lymphocytes (sTIL) are associated with pathologic complete response (pCR) and long-term outcomes for triple-negative breast cancer (TNBC) in the setting of anthracycline-based chemotherapy. The impact of sTILs on refining outcomes beyond prognostic information provided by pCR in anthracycline-free neoadjuvant chemotherapy (NAC) is not known. EXPERIMENTAL DESIGN: This is a pooled analysis of two studies where patients with stage I (T>1 cm)-III TNBC received carboplatin (AUC 6) plus docetaxel (75 mg/m2; CbD) NAC. sTILs were evaluated centrally on pre-treatment hematoxylin and eosin slides using standard criteria. Cox regression analysis was used to examine the effect of variables on event-free survival (EFS) and overall survival (OS). RESULTS: Among 474 patients, 44% had node-positive disease. Median sTILs were 5% (range, 1%-95%), and 32% of patients had ≥30% sTILs. pCR rate was 51%. On multivariable analysis, T stage (OR, 2.08; P = 0.007), nodal status (OR, 1.64; P = 0.035), and sTILs (OR, 1.10; P = 0.011) were associated with pCR. On multivariate analysis, nodal status (HR, 0.46; P = 0.008), pCR (HR, 0.20; P < 0.001), and sTILs (HR, 0.95; P = 0.049) were associated with OS. At 30% cut-point, sTILs stratified outcomes in stage III disease, with 5-year OS 86% versus 57% in ≥30% versus <30% sTILs (HR, 0.29; P = 0.014), and numeric trend in stage II, with 5-year OS 93% versus 89% in ≥30% versus <30% sTILs (HR, 0.55; P = 0.179). Among stage II-III patients with pCR, EFS was better in those with ≥30% sTILs (HR, 0.16; P, 0.047). CONCLUSIONS: sTILs density was an independent predictor of OS beyond clinicopathologic features and pathologic response in patients with TNBC treated with anthracycline-free CbD chemotherapy. Notably, sTILs density stratified outcomes beyond tumor-node-metastasis (TNM) stage and pathologic response. These findings highlight the role of sTILs in patient selection and stratification for neo/adjuvant escalation and de-escalation strategies.

A Cross-Sectional Comparison of Druggable Mutations in Primary Tumors, Metastatic Tissue, Circulating Tumor Cells, and Cell-Free Circulating DNA in Patients with Metastatic Breast Cancer: The MIRROR Study Protocol.

BACKGROUND: Characterization of the driver mutations in an individual metastatic breast cancer (MBC) patient is critical to selecting effective targeted therapies. Currently, it is believed that the limited efficacy of many targeted drugs may be due to the expansion of drug resistant clones with different genotypes that were already present in the primary tumor. Identifying the genomic alterations of these clones, and introducing combined or sequential targeted drug regimens, could lead to a significant increase in the efficacy of currently available targeted therapies. OBJECTIVE: The primary objective of this study is to assess the concordance/discordance of mutations between the primary tumor and metastatic tissue in MBC patients. Secondary objectives include comparing the genomic profiles of circulating tumor cells (CTCs) and circulating free DNA (cfDNA) from peripheral blood with those of the primary tumor and metastatic tissue for each patient, evaluating these mutations in the signaling pathways that are relevant to the disease, and testing the feasibility of introducing liquid biopsy as a translational laboratory tool in clinical practice. METHODS: The multicenter, transversal, observational MIRROR study is currently ongoing in three participating hospitals. All consecutive patients with MBC confirmed by radiologic findings will be screened for eligibility, either at first relapse or if tumor regrowth occurs while on treatment for metastatic disease. RESULTS: Patient recruitment is currently ongoing. To date, 41 patients have a complete set of tissue samples available (plasma, CTCs, and formalin-fixed, paraffin-embedded primary tumor and metastatic tumor). However, none of these samples have undergone nucleic acids extraction or targeted deep sequencing. CONCLUSIONS: The results of this study may have a significant influence on the practical management of patients with MBC, and may provide clues to clinicians that lead towards a better stratification of patients, resulting in more selective and less toxic treatments. Additionally, if genomic mutations found in metastatic tissues are similar to those detected in CTCs and/or cfDNA, liquid biopsies could prove to be a more convenient, non-invasive, and easily accessible source of genomic material for the analysis of mutations and other genomic aberrations in MBC. TRIAL REGISTRATION: ClinicalTrials.gov NCT02626039; https://clinicaltrials.gov/ct2/show/NCT02626039 (Archived by WebCite at http://www.webcitation.org/6jlneVyoz).