Toll-like receptors (TLRs) are pattern-recognition receptors related to the Drosophila Toll protein. TLR activation alerts the immune system to microbial products and initiates innate and adaptive ...immune responses. The naturally powerful immunostimulatory property of TLR agonists can be exploited for active immunotherapy against cancer. Antitumor activity has been demonstrated in several cancers, and TLR agonists are now undergoing extensive clinical investigation. This review discusses recent advances in the field and highlights potential opportunities for the clinical development of TLR agonists as single agent immunomodulators, vaccine adjuvants and in combination with conventional cancer therapies.
Frequent overexpression of programmed death-ligand 1 has recently been demonstrated in metaplastic breast cancer, which is a rare breast cancer subtype with limited treatment options. This report ...describes the clinical course of a patient with metastatic metaplastic breast cancer who had a remarkable response to anti-programmed death-1 therapy with pembrolizumab in combination with nab-paclitaxel. Tissue correlates are presented including tumor-infiltrating lymphocytes and high-programmed death-ligand 1 expression in the tumor.
The aim of the current study was to conduct a pooled analysis of studies that have investigated the prognostic value of tumor-infiltrating lymphocytes (TILs) in early-stage triple negative breast ...cancer (TNBC).
Participating studies had evaluated the percentage infiltration of stromally located TILs (sTILs) that were quantified in the same manner in patient diagnostic samples of early-stage TNBC treated with anthracycline-based chemotherapy with or without taxanes. Cox proportional hazards regression models stratified by trial were used for invasive disease-free survival (iDFS; primary end point), distant disease-free survival (D-DFS), and overall survival (OS), fitting sTILs as a continuous variable adjusted for clinicopathologic factors.
We collected individual data from 2,148 patients from nine studies. Average age was 50 years (range, 22 to 85 years), and 33% of patients were node negative. The average value of sTILs was 23% (standard deviation, 20%), and 77% of patients had 1% or more sTILs. sTILs were significantly lower with older age ( P = .001), larger tumor size ( P = .01), more nodal involvement ( P = .02), and lower histologic grade ( P = .001). A total of 736 iDFS and 548 D-DFS events and 533 deaths were observed. In the multivariable model, sTILs added significant independent prognostic information for all end points (likelihood ratio χ
, 48.9 iDFS; P < .001; χ
, 55.8 D-DFS; P < .001; χ
, 48.5 OS; P < .001). Each 10% increment in sTILs corresponded to an iDFS hazard ratio of 0.87 (95% CI, 0.83 to 0.91) for iDFS, 0.83 (95% CI, 0.79 to 0.88) for D-DFS, and 0.84 (95% CI, 0.79 to 0.89) for OS. In node-negative patients with sTILs ≥ 30%, 3-year iDFS was 92% (95% CI, 89% to 98%), D-DFS was 97% (95% CI, 95% to 99%), and OS was 99% (95% CI, 97% to 100%).
This pooled data analysis confirms the strong prognostic role of sTILs in early-stage TNBC and excellent survival of patients with high sTILs after adjuvant chemotherapy and supports the integration of sTILs in a clinicopathologic prognostic model for patients with TNBC. This model can be found at www.tilsinbreastcancer.org .
Abstract
Background
Understanding the impact of the tumor immune microenvironment and BRCA1/2-related DNA repair deficiencies on the clinical activity of immune checkpoint inhibitors may help ...optimize both patient and treatment selection in metastatic triple-negative breast cancer. In this substudy from the phase 3 IMpassion130 trial, immune biomarkers and BRCA1/2 alterations were evaluated for association with clinical benefit with atezolizumab and nab-paclitaxel (A+nP) vs placebo and nP in unresectable (P+nP) locally advanced or metastatic triple-negative breast cancer.
Methods
Patients were randomly assigned 1:1 to nab-paclitaxel 100 mg/m2 (days 1, 8, and 15 of a 28-day cycle) and atezolizumab 840 mg every 2 weeks or placebo until progression or toxicity. Progression-free survival and overall survival were evaluated based on programmed death-ligand 1 (PD-L1) expression on immune cells (IC) and tumor cells, intratumoral CD8, stromal tumor-infiltrating lymphocytes, and BRCA1/2 mutations.
Results
PD-L1 IC+ in either primary or metastatic tumor tissue was linked to progression-free survival and overall survival benefit with A+nP. PD-L1 IC+ low (26.9%; 243 of 902 patients) and high (13.9%; 125 of 902 patients) populations had improved outcomes that were comparable. Intratumoral CD8 and stromal tumor-infiltrating lymphocytes positivity (sTIL+) were associated with PD-L1 IC+ status; improved outcomes were observed with A+nP vs P+nP only in CD8+ and sTIL+ patients who were also PD-L1 IC+. BRCA1/2 mutations (occurring in 14.5% 89 of 612 patients) were not associated with PD-L1 IC status, and PD-L1 IC+ patients benefited from A+nP regardless of BRCA1/2 mutation status.
Conclusions
Although A+nP was more efficacious in patients with richer tumor immune microenvironment, clinical benefit was only observed in patients whose tumors were PD-L1 IC+.
Recent studies suggest that tumor-infiltrating lymphocytes (TILs) are associated with disease-free (DFS) and overall survival (OS) in operable triple-negative breast cancer (TNBC). We seek to ...validate the prognostic impact of TILs in primary TNBCs in two adjuvant phase III trials conducted by the Eastern Cooperative Oncology Group (ECOG).
Full-face hematoxylin and eosin–stained sections of 506 tumors from ECOG trials E2197 and E1199 were evaluated for density of TILs in intraepithelial (iTILs) and stromal compartments (sTILs). Patient cases of TNBC from E2197 and E1199 were randomly selected based on availability of sections. For the primary end point of DFS, association with TIL scores was determined by fitting proportional hazards models stratified on study. Secondary end points were OS and distant recurrence–free interval (DRFI). Reporting recommendations for tumor marker prognostic studies criteria were followed, and all analyses were prespecified.
The majority of 481 evaluable cancers had TILs (sTILs, 80%; iTILs, 15%). With a median follow-up of 10.6 years, higher sTIL scores were associated with better prognosis; for every 10% increase in sTILs, a 14% reduction of risk of recurrence or death (P = .02), 18% reduction of risk of distant recurrence (P = .04), and 19% reduction of risk of death (P = .01) were observed. Multivariable analysis confirmed sTILs to be an independent prognostic marker of DFS, DRFI, and OS.
In two national randomized clinical trials using contemporary adjuvant chemotherapy, we confirm that stromal lymphocytic infiltration constitutes a robust prognostic factor in TNBCs. Studies assessing outcomes and therapeutic efficacies should consider stratification for this parameter.
Summary Background An abscopal response describes radiotherapy-induced immune-mediated tumour regression at sites distant to the irradiated field. Granulocyte-macrophage colony-stimulating factor is ...a potent stimulator of dendritic cell maturation. We postulated that the exploitation of the pro-immunogenic effects of radiotherapy with granulocyte-macrophage colony-stimulating factor might result in abscopal responses among patients with metastatic cancer. Methods Patients with stable or progressing metastatic solid tumours, on single-agent chemotherapy or hormonal therapy, with at least three distinct measurable sites of disease, were treated with concurrent radiotherapy (35 Gy in ten fractions, over 2 weeks) to one metastatic site and granulocyte-macrophage colony-stimulating factor (125 μg/m2 subcutaneously injected daily for 2 weeks, starting during the second week of radiotherapy). This course was repeated, targeting a second metastatic site. A Simon's optimal two-stage design was chosen for this trial: an additional 19 patients could be enrolled in stage 2 only if at least one patient among the first ten had an abscopal response. If no abscopal responses were seen among the first ten patients, the study would be deemed futile and terminated. The primary endpoint was the proportion of patients with an abscopal response (defined as at least a 30% decrease in the longest diameter of the best responding abscopal lesion). Secondary endpoints were safety and survival. Analyses were done based on intention to treat. The trial has concluded accrual, and is registered with ClinicalTrials.gov , number NCT02474186. Findings From April 7, 2003, to April 3, 2012, 41 patients with metastatic cancer were enrolled. In stage 1 of the Simon's two-stage design, ten patients were enrolled: four of the first ten patients had abscopal responses. Thus, the trial proceeded to stage 2, as planned, and an additional 19 patients were enrolled. Due to protocol amendments 12 further patients were enrolled. Abscopal responses occurred in eight (27·6%, 95% CI 12·7–47·2) of the first 29 patients, and 11 (26·8%, 95% CI 14·2–42·9) of 41 accrued patients (specifically in four patients with non-small-cell lung cancer, five with breast cancer, and two with thymic cancer). The most common grade 3–4 adverse events were fatigue (six patients) and haematological (ten patients). Additionally, a serious adverse event of grade 4 pulmonary embolism occurred in one patient. Interpretation The combination of radiotherapy with granulocyte-macrophage colony-stimulating factor produced objective abscopal responses in some patients with metastatic solid tumours. This finding represents a promising approach to establish an in-situ anti-tumour vaccine. Further research is warranted in this area. Funding New York University School of Medicine's Department of Radiation Oncology and Cancer Institute.
Morphological evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer is gaining momentum as evidence strengthens the clinical relevance of this immunological biomarker. TILs in the ...post-neoadjuvant residual disease setting are acquiring increasing importance as a stratifying marker in clinical trials, considering the raising interest on immunotherapeutic strategies after neoadjuvant chemotherapy. TILs in ductal carcinoma in situ, with or without invasive carcinoma, represent an emerging area of clinical breast cancer research. The aim of this report is to update pathologists, clinicians and researchers on TIL assessment in both the post-neoadjuvant residual disease and the ductal carcinoma in situ settings. The International Immuno-Oncology Working Group proposes a method for assessing TILs in these settings, based on the previously published International Guidelines on TIL Assessment in Breast Cancer. In this regard, these recommendations represent a consensus guidance for pathologists, aimed to achieve the highest possible consistency among future studies.
Although remission rates for metastatic melanoma are generally very poor, some patients can survive for prolonged periods following metastasis. We used gene expression profiling, mitotic index (MI), ...and quantification of tumor infiltrating leukocytes (TILs) and CD3+ cells in metastatic lesions to search for a molecular basis for this observation and to develop improved methods for predicting patient survival. We identified a group of 266 genes associated with postrecurrence survival. Genes positively associated with survival were predominantly immune response related (e.g., ICOS, CD3d, ZAP70, TRAT1, TARP, GZMK, LCK, CD2, CXCL13, CCL19, CCR7, VCAM1) while genes negatively associated with survival were cell proliferation related (e.g., PDE4D, CDK2, GREF1, NUSAP1, SPC24). Furthermore, any of the 4 parameters (prevalidated gene expression signature, TILs, CD3, and in particular MI) improved the ability of Tumor, Node, Metastasis (TNM) staging to predict postrecurrence survival; MI was the most significant contributor (HR = 2.13, P = 0.0008). An immune response gene expression signature and presence of TILs and CD3+ cells signify immune surveillance as a mechanism for prolonged survival in these patients and indicate improved patient subcategorization beyond current TNM staging.
Dendritic cells (DCs) are specialized antigen-presenting cells (APCs) that have an unequaled capacity to initiate primary immune responses, including tolerogenic responses. Because of the importance ...of DCs in the induction and control of immunity, an understanding of their biology is central to the development of potent immunotherapies for cancer, chronic infections, autoimmune disease, and induction of transplantation tolerance. This review discusses recent advances in DC research and the application of this knowledge toward new strategies for the clinical manipulation of DCs for cancer immunotherapy.