Resistance to anticancer therapies includes primary resistance, usually related to lack of target dependency or presence of additional targets, and secondary resistance, mostly driven by adaptation ...of the cancer cell to the selection pressure of treatment. Resistance to targeted therapy is frequently acquired, driven by on-target, bypass alterations, or cellular plasticity. Resistance to immunotherapy is often primary, orchestrated by sophisticated tumor-host-microenvironment interactions, but could also occur after initial efficacy, mostly when only partial responses are obtained. Here, we provide an overview of resistance to tumor and immune-targeted therapies and discuss challenges of overcoming resistance, and current and future directions of development. SIGNIFICANCE: A better and earlier identification of cancer-resistance mechanisms could avoid the use of ineffective drugs in patients not responding to therapy and provide the rationale for the administration of personalized drug associations. A clear description of the molecular interplayers is a prerequisite to the development of novel and dedicated anticancer drugs. Finally, the implementation of such cancer molecular and immunologic explorations in prospective clinical trials could de-risk the demonstration of more effective anticancer strategies in randomized registration trials, and bring us closer to the promise of cure.
Summary Oestrogen-receptor-positive breast cancer is the most common subtype of breast cancer. Endocrine therapies that target the dependence of this subtype on the oestrogen receptor have ...substantial activity, yet the development of resistance to therapy is inevitable in advanced cancer. Major progress has been made in identifying the drivers of oestrogen-receptor-positive breast cancer and the mechanisms of resistance to endocrine therapy. This progress has translated into major advances in the treatment of advanced breast cancer, with several targeted therapies that enhance the efficacy of endocrine therapy; inhibitors of mTOR and inhibitors of the cyclin-dependent kinases CDK4 and CDK6 substantially improve progression-free survival. A new wave of targeted therapies is being developed, including inhibitors of PI3K, AKT, and HER2, and a new generation of oestrogen-receptor degraders. Considerable challenges remain in patient selection, deciding on the most appropriate order in which to administer therapies, and establishing whether cross-resistance occurs between therapies.
The fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) signaling pathway plays a fundamental role in many physiologic processes, including embryogenesis, adult tissue homeostasis, ...and wound healing, by orchestrating angiogenesis. Ligand-independent and ligand-dependent activation have been implicated in a broad range of human malignancies and promote cancer progression in tumors driven by FGF/FGFR oncogenic mutations or amplifications, tumor neoangiogenesis, and targeted treatment resistance, thereby supporting a strong rationale for anti-FGF/FGFR agent development. Efforts are being pursued to develop selective approaches for use against this pathway by optimizing the management of emerging, class-specific toxicity profiles and correctly designing clinical trials to address these different issues.
The development of precision medicine for the management of metastatic breast cancer is an appealing concept; however, major scientific and logistical challenges hinder its implementation in the ...clinic. The identification of driver mutational events remains the biggest challenge, because, with the few exceptions of ER, HER2, PIK3CA and AKT1, no validated oncogenic drivers of breast cancer exist. The development of bioinformatic tools to help identify driver mutations, together with assessment of pathway activation and dependency should help resolve this issue in the future. The occurrence of secondary resistance, such as ESR1 mutations, following endocrine therapy poses a further challenge. Ultra-deep sequencing and monitoring of circulating tumour DNA (ctDNA) could permit early detection of the genetic events underlying resistance and inform on combination therapy approaches. Beside these scientific challenges, logistical and operational issues are a major limitation to the development of precision medicine. For example, the low incidence of most candidate genomic alterations hinders randomized trials, as the number of patients to be screened would be too high. We discuss these limitations and the solutions, which include scaling-up the number of patients screened for identifying a genomic alteration, the clustering of genomic alterations into pathways, and the development of personalized medicine trials.
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 .
The prognosis of early breast cancer (BC) relies on cell autonomous and immune parameters. The impact of the intestinal microbiome on clinical outcome has not yet been evaluated. Shotgun metagenomics ...was used to determine the composition of the fecal microbiota in 121 specimens from 76 early BC patients, 45 of whom were paired before and after chemotherapy. These patients were enrolled in the CANTO prospective study designed to record the side effects associated with the clinical management of BC. We analyzed associations between baseline or post-chemotherapy fecal microbiota and plasma metabolomics with BC prognosis, as well as with therapy-induced side effects. We examined the clinical relevance of these findings in immunocompetent mice colonized with BC patient microbiota that were subsequently challenged with histo-compatible mouse BC and chemotherapy. We conclude that specific gut commensals that are overabundant in BC patients compared with healthy individuals negatively impact BC prognosis, are modulated by chemotherapy, and may influence weight gain and neurological side effects of BC therapies. These findings obtained in adjuvant and neoadjuvant settings warrant prospective validation.
ESR1 mutations are selected by prior aromatase inhibitor (AI) therapy in advanced breast cancer. We assessed the impact of ESR1 mutations on sensitivity to standard therapies in two phase III ...randomized trials that represent the development of the current standard therapy for estrogen receptor-positive advanced breast cancer.
In a prospective-retrospective analysis, we assessed ESR1 mutations in available archived baseline plasma from the SoFEA (Study of Faslodex Versus Exemestane With or Without Arimidex) trial, which compared exemestane with fulvestrant-containing regimens in patients with prior sensitivity to nonsteroidal AI and in baseline plasma from the PALOMA3 (Palbociclib Combined With Fulvestrant in Hormone Receptor-Positive HER2-Negative Metastatic Breast Cancer After Endocrine Failure) trial, which compared fulvestrant plus placebo with fulvestrant plus palbociclib in patients with progression after receiving prior endocrine therapy. ESR1 mutations were analyzed by multiplex digital polymerase chain reaction.
In SoFEA, ESR1 mutations were found in 39.1% of patients (63 of 161), of whom 49.1% (27 of 55) were polyclonal, with rates of mutation detection unaffected by delays in processing of archival plasma. Patients with ESR1 mutations had improved progression-free survival (PFS) after taking fulvestrant (n = 45) compared with exemestane (n = 18; hazard ratio HR, 0.52; 95% CI, 0.30 to 0.92; P = .02), whereas patients with wild-type ESR1 had similar PFS after receiving either treatment (HR, 1.07; 95% CI, 0.68 to 1.67; P = .77). In PALOMA3, ESR1 mutations were found in the plasma of 25.3% of patients (91 of 360), of whom 28.6% (26 of 91) were polyclonal, with mutations associated with acquired resistance to prior AI. Fulvestrant plus palbociclib improved PFS compared with fulvestrant plus placebo in both ESR1 mutant (HR, 0.43; 95% CI, 0.25 to 0.74; P = .002) and ESR1 wild-type patients (HR, 0.49; 95% CI, 0.35 to 0.70; P < .001).
ESR1 mutation analysis in plasma after progression after prior AI therapy may help direct choice of further endocrine-based therapy. Additional confirmatory studies are required.
(rearranged during transfection) gene encodes a receptor tyrosine kinase essential for many physiologic functions, but
aberrations are involved in many pathologies. While
loss-of-function mutations ...are associated with congenital disorders like Hirschsprung disease and CAKUT,
gain-of-function mutations and rearrangements are critical drivers of tumor growth and proliferation in many different cancers.
-altered (
) tumors have been hitherto targeted with multikinase inhibitors (MKI) having anti-
activities, but they inhibit other kinase targets more potently and show limited clinical activities. The lack of target specificity and consequently increased side effects, responsible for dose reduction and drug discontinuation, are critical limitations of MKIs in the clinics. New selective
inhibitors, selpercatinib and pralsetinib, are showing promising activities, improved response rates, and more favorable toxicity profiles in early clinical trials. This review critically discusses the oncogenic activation of
and its role in different kinds of tumors, clinical features of
tumors, clinically actionable genetic
alterations and their diagnosis, and the available data and results of nonselective and selective targeting of
.
The immune system could mediate the antitumor activity of several anticancer treatments. Several chemotherapy compounds, including anthracyclines and oxaliplatin, induce immunogenic cell death that ...in turn activates antitumor immune response. Trastuzumab induces antibody-dependant cell-mediated cytotoxicity. On the basis of this background, immune markers have recently been the focus of intense translational research to predict and monitor the efficacy of treatments. Gene expression arrays and immunohistochemistry have assessed immune activation and infiltration by macrophages, natural killer, and T and B lymphocytes. Using these approaches, several retrospective analyses of large trials have shown that activation of immune pathway may predict treatment efficacy and outcome in patients with breast cancers. As examples, intratumoral infiltration by lymphocytes and interferon-response in primary tumor predicted the efficacy of neoadjuvant chemotherapy. Intratumoral infiltration by lymphocytes was associated with good prognosis in patients with triple-negative breast cancer treated with adjuvant chemotherapy. More recently, it has been suggested that lymphocyte infiltration could also predict efficacy of trastuzumab. Finally, small retrospective studies have suggested that postchemotherapy lymphocyte infiltrates could be associated with better outcome in patients who did not reach pathologic complete response. This body of evidence suggests that assessing immune infiltration and activation could be useful in the future to stratify breast cancer patients. In addition, they provide evidence for the development of immunotherapies in breast cancer patients.
Summary Background mTOR inhibition reverses trastuzumab resistance via the hyperactivated PIK/AKT/mTOR pathway due to PTEN loss, by sensitising PTEN-deficient tumours to trastuzumab. The BOLERO-1 ...study assessed the efficacy and safety of adding everolimus to trastuzumab and paclitaxel as first-line treatment for patients with HER2-positive advanced breast cancer. Methods In this phase 3, randomised, double-blind trial, patients were enrolled across 141 sites in 28 countries. Eligible patients were aged 18 years or older, with locally assessed HER2-positive advanced breast cancer, with Eastern Cooperative Oncology Group (ECOG) performance status of 0–1, who had not received previous trastuzumab or chemotherapy for advanced breast cancer within 12 months of randomisation, had measurable disease as per Response Evaluation Criteria in Solid Tumors (RECIST) or bone lesions in the absence of measurable disease, without previous systemic treatment for advanced disease except endocrine therapy. Patients were randomly assigned (2:1) with an interactive voice and web response system to receive either 10 mg everolimus once a day orally or placebo plus weekly trastuzumab intravenously at 4 mg/kg loading dose on day 1 with subsequent weekly doses of 2 mg/kg of each 4 week cycle plus paclitaxel intravenously at a dose of 80 mg/m2 on days 1, 8, and 15 of each 4 week cycle. Randomisation was stratified according to previous use of trastuzumab and visceral metastasis. Patients and investigators were masked to the assigned treatments. Identity of experimental treatments was concealed by use of everolimus and placebo that were identical in packaging, labelling, appearance, and administration schedule. The two primary objectives were investigator-assessed progression-free survival in the full study population and in the subset of patients with hormone receptor-negative breast cancer at baseline; the latter was added during the course of the study, before unmasking based on new clinical and biological findings from other studies. All efficacy analyses were based on the intention-to-treat population. Enrolment for this trial is closed and results of the final progression-free survival analyses are presented here. This trial is registered with ClinicalTrials.gov , number NCT00876395. Findings Between Sept 10, 2009, and Dec 16, 2012, 719 patients were randomly assigned to receive everolimus (n=480) or placebo (n=239). Median follow-up was 41·3 months (IQR 35·4–46·6). In the full population, median progression-free survival was 14·95 months (95% CI 14·55–17·91) with everolimus versus 14·49 months (12·29–17·08) with placebo (hazard ratio 0·89, 95% CI 0·73–1·08; p=0·1166). In the HR-negative subpopulation (n=311), median progression-free survival with everolimus was 20·27 months (95% CI 14·95–24·08) versus 13·08 months (10·05–16·56) with placebo (hazard ratio 0·66, 95% CI 0·48–0·91; p=0·0049); however, the protocol-specified significance threshold (p=0·0044) was not crossed. The most common adverse events with everolimus were stomatitis (314 67% of 472 patients in the everolimus group vs 77 32% of 238 patients in the placebo group), diarrhoea (267 57% vs 111 47% patients), and alopecia (221 47% vs 125 53%). The most frequently reported grade 3 or 4 adverse events in the everolimus group versus the placebo group were neutropenia (117 25% vs 35 15%), stomatitis (59 13% vs three 1%), anaemia (46 10% vs six 3%) and diarrhoea (43 9% vs 10 4%) On-treatment adverse event-related deaths were reported in 17 (4%) patients in the everolimus group and none in the placebo group. Interpretation Although progression-free survival was not significantly different between groups in the full analysis population, the 7·2 months prolongation we noted with the addition of everolimus in the HR-negative, HER2-positive population warrants further investigation, even if it did not meet prespecified criteria for significance. The safety profile was generally consistent with what was previously reported in BOLERO-3. Proactive monitoring and early management of adverse events in patients given everolimus and chemotherapy is crucial. Funding Novartis Pharmaceuticals.
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