The impressive clinical activity of small-molecule receptor tyrosine kinase inhibitors for oncogene-addicted subgroups of non-small-cell lung cancer (for example, those driven by activating mutations ...in the gene encoding epidermal growth factor receptor (EGFR) or rearrangements in the genes encoding the receptor tyrosine kinases anaplastic lymphoma kinase (ALK), ROS proto-oncogene 1 (ROS1) and rearranged during transfection (RET)) has established an oncogene-centric molecular classification paradigm in this disease. However, recent studies have revealed considerable phenotypic diversity downstream of tumour-initiating oncogenes. Co-occurring genomic alterations, particularly in tumour suppressor genes such as TP53 and LKB1 (also known as STK11), have emerged as core determinants of the molecular and clinical heterogeneity of oncogene-driven lung cancer subgroups through their effects on both tumour cell-intrinsic and non-cell-autonomous cancer hallmarks. In this Review, we discuss the impact of co-mutations on the pathogenesis, biology, microenvironmental interactions and therapeutic vulnerabilities of non-small-cell lung cancer and assess the challenges and opportunities that co-mutations present for personalized anticancer therapy, as well as the expanding field of precision immunotherapy.
Angiogenesis, the sprouting of new blood vessels from existing vessels, is one of six known mechanisms employed by solid tumors to recruit blood vessels necessary for their initiation, growth, and ...metastatic spread. The vascular network within the tumor facilitates the transport of nutrients, oxygen, and immune cells and is regulated by pro- and anti-angiogenic factors. Nearly four decades ago, VEGF was identified as a critical factor promoting vascular permeability and angiogenesis, followed by identification of VEGF family ligands and their receptors (VEGFR). Since then, over a dozen drugs targeting the VEGF/VEGFR pathway have been approved for approximately 20 solid tumor types, usually in combination with other therapies. Initially designed to starve tumors, these agents transiently "normalize" tumor vessels in preclinical and clinical studies, and in the clinic, increased tumor blood perfusion or oxygenation in response to these agents is associated with improved outcomes. Nevertheless, the survival benefit has been modest in most tumor types, and there are currently no biomarkers in routine clinical use for identifying which patients are most likely to benefit from treatment. However, the ability of these agents to reprogram the immunosuppressive tumor microenvironment into an immunostimulatory milieu has rekindled interest and has led to the FDA approval of seven different combinations of VEGF/VEGFR pathway inhibitors with immune checkpoint blockers for many solid tumors in the past 3 years. In this review, we discuss our understanding of the mechanisms of response and resistance to blocking VEGF/VEGFR, and potential strategies to develop more effective therapeutic approaches.
Our previously published findings reported that local consolidative therapy (LCT) with radiotherapy or surgery improved progression-free survival (PFS) and delayed new disease in patients with ...oligometastatic non-small-cell lung cancer (NSCLC) that did not progress after front-line systemic therapy. Herein, we present the longer-term overall survival (OS) results accompanied by additional secondary end points.
This multicenter, randomized, phase II trial enrolled patients with stage IV NSCLC, three or fewer metastases, and no progression at 3 or more months after front-line systemic therapy. Patients were randomly assigned (1:1) to maintenance therapy or observation (MT/O) or to LCT to all active disease sites. The primary end point was PFS; secondary end points were OS, toxicity, and the appearance of new lesions. All analyses were two sided, and
values less than .10 were deemed significant.
The Data Safety and Monitoring Board recommended early trial closure after 49 patients were randomly assigned because of a significant PFS benefit in the LCT arm. With an updated median follow-up time of 38.8 months (range, 28.3 to 61.4 months), the PFS benefit was durable (median, 14.2 months 95% CI, 7.4 to 23.1 months with LCT
4.4 months 95% CI, 2.2 to 8.3 months with MT/O;
= .022). We also found an OS benefit in the LCT arm (median, 41.2 months 95% CI, 18.9 months to not reached with LCT
17.0 months 95% CI, 10.1 to 39.8 months with MT/O;
= .017). No additional grade 3 or greater toxicities were observed. Survival after progression was longer in the LCT group (37.6 months with LCT
9.4 months with MT/O;
= .034). Of the 20 patients who experienced progression in the MT/O arm, nine received LCT to all lesions after progression, and the median OS was 17 months (95% CI, 7.8 months to not reached).
In patients with oligometastatic NSCLC that did not progress after front-line systemic therapy, LCT prolonged PFS and OS relative to MT/O.
Small cell lung cancer (SCLC) is an exceptionally lethal malignancy for which more effective therapies are urgently needed. Several lines of evidence, from SCLC primary human tumours, patient-derived ...xenografts, cancer cell lines and genetically engineered mouse models, appear to be converging on a new model of SCLC subtypes defined by differential expression of four key transcription regulators: achaete-scute homologue 1 (ASCL1; also known as ASH1), neurogenic differentiation factor 1 (NeuroD1), yes-associated protein 1 (YAP1) and POU class 2 homeobox 3 (POU2F3). In this Perspectives article, we review and synthesize these recent lines of evidence and propose a working nomenclature for SCLC subtypes defined by relative expression of these four factors. Defining the unique therapeutic vulnerabilities of these subtypes of SCLC should help to focus and accelerate therapeutic research, leading to rationally targeted approaches that may ultimately improve clinical outcomes for patients with this disease.
In
-mutant lung adenocarcinoma, tumors with LKB1 loss (KL) are highly enriched for concurrent
mutations, which activate the KEAP1/NRF2 pathway (KLK). Here, we investigated the biological consequences ...of these cooccurring alterations and explored whether they conferred specific therapeutic vulnerabilities. Compared with KL tumors, KLK tumors exhibited increased expression of genes involved in glutamine metabolism, the tricarboxylic acid cycle, and the redox homeostasis signature. Using isogenic pairs with knockdown or overexpression of LKB1, KEAP1, and NRF2, we found that LKB1 loss results in increased energetic and redox stress marked by increased levels of intracellular reactive oxygen species and decreased levels of ATP, NADPH/NADP
ratio, and glutathione. Activation of the KEAP1/NRF2 axis in LKB1-deficient cells enhanced cell survival and played a critical role in the maintenance of energetic and redox homeostasis in a glutamine-dependent manner. LKB1 and the KEAP1/NRF2 pathways cooperatively drove metabolic reprogramming and enhanced sensitivity to the glutaminase inhibitor CB-839
and
. Overall, these findings elucidate the adaptive advantage provided by KEAP1/NRF2 pathway activation in KL tumors and support clinical testing of glutaminase inhibitor in subsets of KRAS-mutant lung adenocarcinoma. SIGNIFICANCE: In
-mutant non-small cell lung cancer, LKB1 loss results in enhanced energetic/redox stress, which is tolerated, in part, through cooccurring KEAP1/NRF2-dependent metabolic adaptations, thus enhancing glutamine dependence and vulnerability to glutaminase inhibition.
http://cancerres.aacrjournals.org/content/canres/79/13/3251/F1.large.jpg.
Despite recent advances in the use of immunotherapy, only a minority of patients with small cell lung cancer (SCLC) respond to immune checkpoint blockade (ICB). Here, we show that targeting the DNA ...damage response (DDR) proteins PARP and checkpoint kinase 1 (CHK1) significantly increased protein and surface expression of PD-L1. PARP or CHK1 inhibition remarkably potentiated the antitumor effect of PD-L1 blockade and augmented cytotoxic T-cell infiltration in multiple immunocompetent SCLC
models. CD8
T-cell depletion reversed the antitumor effect, demonstrating the role of CD8
T cells in combined DDR-PD-L1 blockade in SCLC. We further demonstrate that DDR inhibition activated the STING/TBK1/IRF3 innate immune pathway, leading to increased levels of chemokines such as CXCL10 and CCL5 that induced activation and function of cytotoxic T lymphocytes. Knockdown of
and
successfully reversed the antitumor effect of combined inhibition of DDR and PD-L1. Our results define previously unrecognized innate immune pathway-mediated immunomodulatory functions of DDR proteins and provide a rationale for combining PARP/CHK1 inhibitors and immunotherapies in SCLC. SIGNIFICANCE: Our results define previously unrecognized immunomodulatory functions of DDR inhibitors and suggest that adding PARP or CHK1 inhibitors to ICB may enhance treatment efficacy in patients with SCLC. Furthermore, our study supports a role of innate immune STING pathway in DDR-mediated antitumor immunity in SCLC.
.
.
KRAS and STK11 (LKB1) co-mutated (KL) tumors define an immunologically cold and anti-PD-(L)1-refractory non-small-cell lung cancer (NSCLC) subset. In this issue of Cancer Cell, Kitajima et al. ...outline a strategy to unleash innate immunity in KL tumors by utilizing epigenetic de-repression of STING and pulsed inhibition of spindle assembly checkpoint kinase MPS1.
KRAS and STK11 (LKB1) co-mutated (KL) tumors define an immunologically cold and anti-PD-(L)1-refractory non-small-cell lung cancer (NSCLC) subset. In this issue of Cancer Cell, Kitajima et al. outline a strategy to unleash innate immunity in KL tumors by utilizing epigenetic de-repression of STING and pulsed inhibition of spindle assembly checkpoint kinase MPS1.
Salivary gland adenoid cystic carcinoma (ACC) has heterogeneous clinical behavior. Currently, all patients are treated uniformly, and no standard-of-care systemic therapy exists for metastatic ACC. ...We conducted an integrated proteogenomic analyses of ACC tumors to identify dysregulated pathways and propose a classification with therapeutic implications.
RNA/DNA sequencing of 54 flash-frozen salivary ACCs and reverse phase protein array (RPPA) in 38 specimens were performed, with validation by Western blotting and/or IHC. Three independent ACC cohorts were used for validation.
Both unbiased RNA sequencing (RNA-seq) and RPPA analysis revealed two molecular subtypes: ACC-I (37%) and ACC-II (63%). ACC-I had strong upregulation of
, MYC target genes, and mRNA splicing, enrichment of
-activating mutations, and dramatically worse prognosis. ACC-II exhibited upregulation of
and receptor tyrosine kinases (AXL, MET, and EGFR) and less aggressive clinical course. TP63 and MYC were sufficient to assign tumors to ACC subtypes, which was validated in one independent cohort by IHC and two additional independent cohorts by RNA-seq. Furthermore, IHC staining for MYC and P63 protein levels can be used to identify ACC subtypes, enabling rapid clinical deployment to guide therapeutic decisions. Our data suggest a model in which ACC-I is driven by MYC signaling through either NOTCH mutations or direct amplification, which in turn suppress P63 signaling observed in ACC-II, producing unique therapeutic vulnerabilities for each subtype.
Cooccurrence of multiple actionable protein/pathways alterations in each subtype indicates unique therapeutic vulnerabilities and opportunities for optimal combination therapy for this understudied and heterogeneous disease.
Despite molecular and clinical heterogeneity, small cell lung cancer (SCLC) is treated as a single entity with predictably poor results. Using tumor expression data and non-negative matrix ...factorization, we identify four SCLC subtypes defined largely by differential expression of transcription factors ASCL1, NEUROD1, and POU2F3 or low expression of all three transcription factor signatures accompanied by an Inflamed gene signature (SCLC-A, N, P, and I, respectively). SCLC-I experiences the greatest benefit from the addition of immunotherapy to chemotherapy, while the other subtypes each have distinct vulnerabilities, including to inhibitors of PARP, Aurora kinases, or BCL-2. Cisplatin treatment of SCLC-A patient-derived xenografts induces intratumoral shifts toward SCLC-I, supporting subtype switching as a mechanism of acquired platinum resistance. We propose that matching baseline tumor subtype to therapy, as well as manipulating subtype switching on therapy, may enhance depth and duration of response for SCLC patients.
Display omitted
•Differential expression of ASCL1, NEUROD1, and POU2F3 defines SCLC subtypes•An inflamed SCLC subtype (SCLC-I) has low expression of ASCL1, NEUROD1, and POU2F3•SCLC-I experiences greatest benefit from the addition of anti-PD-L1 to chemotherapy•Subtype switching accompanies acquired resistance to platinum chemotherapy
Gay et al. provide a classification for four subtypes of small cell lung cancer, each with unique molecular features and therapeutic vulnerabilities. An inflamed, mesenchymal subtype predicts benefit with the addition of immunotherapy to chemotherapy. Intratumoral switching between chemosensitive and chemoresistant subtypes accompanies therapeutic resistance.