The consequences of neoadjuvant chemotherapy (NAC) for PD-L1 activity in triple-negative breast cancers (TNBC) are not well-understood. This is an important issue as PD-LI might act as a biomarker for immune checkpoint inhibitors’ (ICI) efficacy, at a time where ICI are undergoing rapid development and could be beneficial in patients who do not achieve a pathological complete response. We used immunohistochemistry to assess PD-L1 expression in surgical specimens (E1L3N clone, cutoff for positivity: ≥1%) on both tumor (PD-L1-TC) and immune cells (PD-L1-IC) from a cohort of T1-T3NxM0 TNBCs treated with NAC. PD-L1-TC was detected in 17 cases (19.1%) and PD-L1-IC in 14 cases (15.7%). None of the baseline characteristics of the tumor or the patient were associated with PD-L1 positivity, except for pre-NAC stromal TIL levels, which were higher in post-NAC PD-L1-TC-positive than in negative tumors. PD-L1-TC were significantly associated with a higher residual cancer burden (p = 0.035) and aggressive post-NAC tumor characteristics, whereas PD-L1-IC were not. PD-L1 expression was not associated with relapse-free survival (RFS) (PD-L1-TC, p = 0.25, and PD-L1-IC, p = 0.95) or overall survival (OS) (PD-L1-TC, p = 0.48, and PD-L1-IC, p = 0.58), but high Ki67 levels after NAC were strongly associated with a poor prognosis (RFS, p = 0.0014, and OS, p = 0.001). A small subset of TNBC patients displaying PD-L1 expression in the context of an extensive post-NAC tumor burden could benefit from ICI treatment after standard NAC.
Abstract Background Activating mutations in the estrogen receptor 1 ( ESR1 ) gene are recurrent mechanisms of acquired resistance to aromatase inhibitors (AI), and may be the target of other selective estrogen receptor down-regulators. To assess the clinical utility of monitoring ESR1 resistant mutations, a droplet digital PCR (ddPCR)-based assay compatible with body fluids is ideal due to its cost-effectiveness and quick turnaround. Methods We designed a multiplex ddPCR, which combines a drop-off assay, targeting the clustered hotspot mutations found in exon 8, with another pair of probes interrogating the E380Q mutation in exon 5. We assessed its sensitivity in vitro using synthetic oligonucleotides, harboring E380Q, L536R, Y537C, Y537N, Y537S or D538G mutations. Validation of the assay was performed on plasma samples from a prospective study and compared to next generation sequencing (NGS) data. Results The multiplex ESR1 -ddPCR showed a high sensitivity with a limit of detection ranging from 0.07 to 0.19% in mutant allele frequency depending on the mutation tested. The screening of plasma samples from patients with AI-resistant metastatic breast cancer identified ESR1 mutations in 29% of them with perfect concordance (and higher sensitivity) to NGS data obtained in parallel. Additionally, this test identifies patients harboring polyclonal alterations. Furthermore, the monitoring of ctDNA using this technique during treatment follow-up predicts the radiological response to palbociclib-fulvestrant. Conclusion The multiplex ESR1 -ddPCR detects, in a single reaction, the most frequent ESR1 activating mutations and is compatible with plasma samples. This method is thus suitable for real-time ESR1 mutation monitoring in large cohorts of patients. Statement of translational relevance Exons 5 and 8 mutations in ESR1 are recurrent mechanisms of resistance to aromatase inhibitors (AI) in estrogen receptor (ER)-positive metastatic breast cancer and may be targeted by selective ER down-regulators. We implemented a novel droplet digital PCR, which allows for the detection of the most frequent ESR1 mutations in circulating cell-free DNA. In prospectively collected plasma samples, ESR1 mutations were found in 29% of AI-resistant patients, with excellent concordance and higher sensitivity to next generation sequencing. Moreover, circulating ESR1 mutations appear to be reliable markers for ctDNA monitoring in order to predict treatment response. Ultimately, the short turnaround time, high sensitivity and limited cost of the ESR1 -ddPCR are compatible with repeated samplings to detect the onset of resistance to AI before the radiological progression. This opens a window of opportunity to develop new clinical strategies for breast cancer hormone therapy, as tested in an ongoing phase 3 trial. List of abbreviations AI Aromatase Inhibitor cfDNA Cell-free DNA ctDNA Circulating tumor DNA ddPCR Droplet digital PCR ER+ HER2-MBC ER+ HER2-negative Metastatic Breast Cancer ER Estrogen Receptor ER+ Estrogen Receptor positive LOB Limit of blank LOD Limit of detection MAF Mutant Allele Frequency PBMC Peripheral blood mononuclear cells PD Progressive disease SD Standard deviation ToP Time of progression WT Wild type Human genes ESR1 : Estrogen Receptor 1 HER2 : Human Epidermal Growth Factor Receptor 2 EGFR : Epithelial Growth Factor Receptor KRAS : KRAS proto-oncogene, GTPase BRAF : B-Raf Proto-Oncogene, Serine/Threonine kinase
Abstract Purpose: High levels of tumor-infiltrating lymphocytes (TILs) before neoadjuvant chemotherapy (NAC) are associated with higher pathological complete response (pCR) rates, and better survival in TNBC and HER2-positive breast cancers (BCs). We investigated the value of changes in TIL levels and final TIL levels after treatment, by evaluating lymphocyte infiltration before and after NAC in a real-life BC cohort. Patients and methods: We assessed stromal TIL levels in 716 pre- and post-treatment matched paired specimens, according to the guidelines of the international TIL working group. Results: Pre-NAC TIL levels were higher in tumors for which pCR was achieved than in cases of residual disease (33.9% versus 20.3%, p=0.001), in luminal tumors and TNBCs, but not in HER2-positive BCs, (pInteraction =0.001). The association between pre-NAC TIL levels and pCR was non-linear in TNBCs (p=0.005). Mean TIL levels decreased during NAC (pre-NAC TILs: 24.1% versus post-NAC TILs: 13.0%, p<0.001). This decrease was strongly associated with high pCR rates, and TIL level variation was strongly inversely correlated with pre-NAC TIL levels (r=-0.80, p<0.001). Pre-NAC TILs and disease-free survival (DFS) were associated in a non-linear manner (p<0.001). High post-NAC TIL levels were associated with aggressive tumor characteristics and with impaired DFS in HER2-positive BCs (HR=1.04, CI [1.02-1.06], p=0.001), but not in luminal tumors or TNBCs (pInteraction =0.04). Conclusion: The associations of pre, post-NAC TIL levels with response to treatment and DFS differ between BC subtypes and may deviate from linearity. The characterization of immune subpopulations may improve our understanding of the complex interactions between pre- or post-NAC setting, BC subtype, response to treatment and prognosis. Citation Format: Hamy A-S, Bonsang-Kitzis H, De Croze D, Laas E, Darrigues L, Topciu L, Menet E, Vincent-Salomon A, Lerebours F, Pierga J-Y, Brain E, Feron J-G, Benchimol G, Lam G-T, Laé M, Reyal F. Interaction between molecular subtype and stromal immune infiltration dynamics in breast cancer patients treated with neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-11-01.
Breast cancer (BC) is the leading cause of cancer and cancer mortality among women worldwide. Surgery is the primary therapeutic strategy of BC in most of the cases. Efficient carcinologic and aesthetic resection requires breast surgeons to accurately understand medical images. Virtual reality (VR) is a promising avenue to improve surgical diagnosis and planning by producing high-precision images. Hereafter we report three cases of patients for which using AVATAR medical device for 3D visualization with VR would have helped to decide surgical strategy and adapt surgical procedure. The three cases are real-life examples of using the VR-AVATAR medical device for breast cancer surgery treatment: evaluation of the tumor response to neoadjuvant chemotherapy, decision for breast conservative or radical treatment, decision for loco-regional treatment in metastatic setting. Through these three real-life cases, we describe the potential impact of VR-AVATAR medical device use in clinical daily practice in breast cancer surgery. It seems like a useful tool, easy to use, providing high-quality images, helping with surgery planning and decisions.
