Chemotherapy for locally advanced and metastatic pulmonary carcinoid tumors

Objectives The optimal management of locally advanced and metastatic pulmonary carcinoid tumors remains to be determined. Materials and methods A retrospective review was conducted on patients with typical and atypical pulmonary carcinoid tumors treated at our institutions between 1990 and 2012. Results 300 patients were identified with pulmonary carcinoid, (80 patients with atypical carcinoid), of whom 29 presented with metastatic disease (16 atypical). Of evaluable patients, 26 (41%) with stages I–III atypical carcinoid tumors recurred at a median time of 3.7 years (range, 0.4–32), compared to 3 (1%) patients with typical carcinoid (range, 8–12.3). 39 patients were treated with chemotherapy, including 30 patients with metastatic disease (27 atypical), and 7 patients were treated with adjuvant platinum–etoposide chemoradiation (6 atypical, 1 typical, 6 stage IIIA, 1 stage IIB). At a median follow-up of 2 years there were 2 recurrences in the 7 patients receiving adjuvant treatment. Median survival after diagnosis of metastatic disease for patients with atypical pulmonary carcinoid was 3.3 years with a 5-year survival of 24%. Treatment regimens showing efficacy in pulmonary carcinoid include 15 patients treated with octreotide-based therapies (10% response rate (RR), 70% disease control rate (DCR), 15 month median progression-free survival (PFS)), 13 patients treated with etoposide + platinum (23% RR, 69% DCR, 7 month median PFS), and 14 patients treated with temozolomide-based therapies (14% RR, 57% DCR, 10 month median PFS). 8 of 10 patients with octreotide-avid disease treated with an octreotide-based regimen experienced disease control (1 partial response, 7 stable disease) for a median of 18 months (range 6–72 months). Conclusions These results support our previous finding that a subset of pulmonary carcinoid tumors are responsive to chemotherapy

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Genetic and molecular analyses of the Lowe syndrome gene (OCRL-1) and its highly related homologue inositol polyphosphate 5-phosphatase (INPP5B)

Lowe syndrome or OCRL is an X-linked human genetic disorder characterized by mental retardation, congenital cataracts and renal Fanconi syndrome, a proximal tubular dysfunction. The gene for OCRL, OCRL-1, is localized to the Xq25-q26 region and was isolated through standard positional cloning techniques. Biochemically, the protein product of the OCRL-1 gene is a phosphatidyl inositol 4,5-bisphosphate 5-phosphatase. In an attempt to further understand the pathogenesis of Lowe syndrome and to create a potential animal model, we have used targeted disruption in embryonic stem cells in order to make mice deficient in Ocrl-1. These mice share the molecular and biochemical defects of human Lowe syndrome but do not develop congenital cataracts, renal Fanconi syndrome or mental retardation as seen in the human disorder. As a way to understand this discrepancy between humans and mice we have begun to identify and study OCRL-1 related genes since they could compensate for the lack of Ocrl-1 in our mice. Database searches reveal seven human genes that share four highly conserved domains. The most closely related gene to OCRL-1 is INPP5B which encodes for a 75 kDa inositol polyphosphate 5-phosphatase and is 53% identical at the amino acid level. Initial genetic studies of INPP5B have focused on identifyng its chromosomal location in both humans and mice. Our studies show that human INPP5B maps to chromosome 1p34. In mice, Inpp5b maps to distal chromosome 4, a homologous position to human 1p34. Inpp5b maps near a previously identified mouse mutation called dysgenetic lens (dyl), a congenital cataract mutation. However, using a genetic approach we could show that they are two separate loci, Inpp5b being more distal on chromosome 4 than dyl. In order to formally test if Inpp5b compensates for Ocrl-1 we have attempted to make mice deficient in Inpp5b. Much like the Ocrl\sp- mice these mice develop normally without any obvious phenotypic consequences. However, a molecular analysis of these mice shows that the targeted Inpp5b mice are not completely null at the Inpp5b locus. The targeting event causes a splicing back into frame with a subsequent deletion of 10 amino acids which are highly conserved. The targeted Inpp5b mRNA is found at normal levels in brain but is decreased to about 10% of normal in other tissues examined. Future experiments will include additional breeding in order to generate the double knock-out mice to test if Inpp5b compensates for the lack of Ocrl-1. In addition, further studies are needed on the targeted Inpp5b mice to determine the effect of this mutation on protein stability and biochemical function. These studies provide genetic tools which can be further used to study PIP\sb2 metabolism in mice to understand differences that exist in this pathway between humans and mice

ROS1 Immunohistochemistry for Detection of ROS1-Rearranged Lung Adenocarcinomas

ROS1 gene rearrangements are reported in 1–2% of lung adenocarcinomas (ACA) and are associated with response to the multitargeted tyrosine kinase inhibitor, crizotinib. ROS1 rearrangements can be detected using fluorescence in situ hybridization (FISH) however immunohistochemistry (IHC) for ROS1 protein is a promising alternate screening modality. In this study we examine the correlation between ROS1 IHC and FISH and describe the clinicopathologic characteristics of ROS1-rearranged lung tumors. ROS1 IHC was performed using clone D4D6 (Cell Signaling Technology, Danvers, MA) on whole tissue sections. In a validation cohort, IHC was compared to ROS1 break-apart FISH in 53 cases of lung ACA enriched for an absence of known genetic alterations and never-smoking status. In a screening cohort, we performed ROS1 IHC on 167 consecutive cases of lung ACA from a routine molecular diagnostics practice and confirmed positive results by FISH. In the validation cohort, 6 cases (11%) were both FISH and IHC positive. One FISH-negative case was strongly ROS1 IHC positive. All IHC negative cases were FISH negative. In the screening cohort, 2 of 167 (1.2%) had strong, diffuse ROS1 protein expression; a rearrangement was confirmed by FISH in both. ROS1-translocated tumors were wild type for EGFR, KRAS, and ALK and commonly had solid growth with mucinous/cribriform features and psammomatous calcification. ROS1 protein expression in tumor cells is 100% sensitive and 92% specific for ROS1 rearrangements by FISH. ROS1 IHC is an effective screening tool for this rare but clinically important subset of lung ACA

Clinical, Pathologic, and Biologic Features Associated with BRAF Mutations in Non-Small Cell Lung Cancer

Purpose BRAF mutations are found in a subset of non-small cell lung cancers (NSCLCs). We examined the clinical characteristics and treatment outcomes of patients with NSCLC harboring BRAF mutations. Experimental Design Using DNA sequencing, we successfully screened 883 NSCLC patients for BRAF mutations between 7/1/09 and 7/16/12. Baseline characteristics and treatment outcomes were compared between patients with and without BRAF mutations. Wild type controls consisted of NSCLC patients without a somatic alteration in BRAF, KRAS, EGFR, and ALK. In vitro studies assessed the biological properties of selected non-V600E BRAF mutations identified from NSCLC patients. Results Of 883 tumors screened, 36 (4%) harbored BRAF mutations (V600E: 18; non-V600E: 18) and 257 were wild type for BRAF, EGFR, KRAS, and ALK negative. Twenty-nine of the 36 BRAF mutant patients were smokers. There were no distinguishing clinical features between BRAF mutant and wild type patients. Advanced NSCLC patients with BRAF mutations and wild type tumors showed similar response rates and progression-free survival (PFS) to platinum-based combination chemotherapy and no difference in overall survival. Within the BRAF cohort, patients with V600E mutated tumors had a shorter PFS to platinum-based chemotherapy compared to those with non-V600E mutations, although this did not reach statistical significance (4.1 versus 8.9 months; P=0.297). We identified five BRAF mutations not previously reported in NSCLC; two of the five were associated with increased BRAF kinase activity. Conclusions BRAF mutations occur in 4% of NSCLCs and half are non-V600E. Prospective trials are ongoing to validate BRAF as a therapeutic target in NSCLC

EGFRMutation Is a Better Predictor of Response to Tyrosine Kinase Inhibitors in Non–Small Cell Lung Carcinoma Than FISH, CISH, and Immunohistochemistry

About 10% of patients with non–small cell lung carcinoma (NSCLC) respond to epidermal growth factor receptor (EGFR)-targeted tyrosine kinase inhibitors (TKIs). More than 75% of “responders” have activating mutations in EGFR. However, mutation analysis is not widely available, and proposed alternatives (in situ hybridization and immunohistochemical analysis) have shown inconsistent associations with outcome. Fluorescence in situ hybridization (FISH), chromogenic in situ hybridization (CISH), immunohistochemical analysis, and DNA sequencing were compared in this study of 40 NSCLC samples from TKI-treated patients. Response rates were 12 of 19 in EGFR-mutant vs 1 of 20 EGFR wild-type tumors (P = .0001), 7 of 19 FISH+ vs 4 of 17 FISH– tumors (not significant [NS]), 5 of 16 CISH+ vs 6 of 21 CISH– tumors (NS), and 3 of 9 immunohistochemically positive vs 7 of 22 immunohistochemically negative tumors (NS). EGFR mutation was associated with improved progression-free survival (P = .0004). Increased copy number (FISH or CISH) and protein expression (immunohistochemical) did not independently predict outcome. Thus, EGFR sequence analysis was the only method useful for predicting response and progression-free survival following TKI therapy in NSCLC

MET Exon 14 Mutations in Non–Small-Cell Lung Cancer Are Associated With Advanced Age and Stage-Dependent MET Genomic Amplification and c-Met Overexpression

Purpose Non–small-cell lung cancers (NSCLCs) harboring mutations in MET exon 14 and its flanking introns may respond to c-Met inhibitors. We sought to describe the clinical, pathologic, and genomic characteristics of patients with cancer with MET exon 14 mutations. Patients and Methods We interrogated next-generation sequencing results from 6,376 cancers to identify those harboring MET exon 14 mutations. Clinical characteristics of MET exon 14 mutated NSCLCs were compared with those of NSCLCs with activating mutations in KRAS and EGFR. Co-occurring genomic mutations and copy number alterations were identified. c-Met immunohistochemistry and real-time polymerase chain reaction to detect exon 14 skipping were performed where sufficient tissue was available. Results MET exon 14 mutations were identified in 28 of 933 nonsquamous NSCLCs (3.0%) and were not seen in other cancer types in this study. Patients with MET exon 14–mutated NSCLC were significantly older (median age, 72.5 years) than patients with EGFR-mutant (median age, 61 years; P < .001) or KRAS-mutant NSCLC (median age, 65 years; P < .001). Among patients with MET exon 14 mutations, 68% were women, and 36% were never-smokers. Stage IV MET exon 14–mutated NSCLCs were significantly more likely to have concurrent MET genomic amplification (mean ratio of MET to chromosome 7, 4.3) and strong c-Met immunohistochemical expression (mean H score, 253) than stage IA to IIIB MET exon 14–mutated NSCLCs (mean ratio of MET to chromosome 7, 1.4; P = .007; mean H score, 155; P = .002) and stage IV MET exon 14–wild-type NSCLCs (mean ratio of MET to chromosome 7, 1.2; P < .001; mean H score, 142; P < .001). A patient whose lung cancer harbored a MET exon 14 mutation with concurrent genomic amplification of the mutated MET allele experienced a major partial response to the c-Met inhibitor crizotinib. Conclusion MET exon 14 mutations represent a clinically unique molecular subtype of NSCLC. Prospective clinical trials with c-Met inhibitors will be necessary to validate MET exon 14 mutations as an important therapeutic target in NSCLC

Lung Adenocarcinoma with EGFR Amplification Has Distinct Clinicopathologic and Molecular Features in Never-Smokers

In a subset of lung adenocarcinomas the epidermal growth factor receptor (EGFR) is activated by kinase domain mutations and/or gene amplification, but the interaction between the two types of abnormalities is complex and unclear. We selected to study 99 consecutive never-smoking women of East Asian origin with lung adenocarcinomas that were characterized by histologic subtype. We analyzed EGFR mutations by PCR-capillary sequencing, EGFR copy number abnormalities by fluorescence and chromogenic in situ hybridization and quantitative PCR, and EGFR expression by immunohistochemistry with both specific antibodies against exon 19 deletion-mutated EGFR and total EGFR. We compared molecular and clinicopathologic features with disease-free survival. Lung adenocarcinomas with EGFR amplification had significantly more EGFR exon 19 deletion mutations than adenocarcinomas with disomy, low and high polysomy (100% v 54%, P=0.009). EGFR amplification occurred invariably on the mutated and not the wildtype allele (median mutated:wildtype ratios 14.0 v .33, P=0.003), was associated with solid histology (P=0.008), and advanced clinical stage (P=0.009). EGFR amplification was focally distributed in lung cancer specimens, mostly in regions with solid histology. Patients with EGFR amplification had a significantly worse outcome in univariate analysis (median disease-free survival 16 v 31 months, P=0.01) and when adjusted for stage (P=0.027). Lung adenocarcinomas with EGFR amplification have a unique association with exon 19 deletion mutations and demonstrate distinct clinicopathologic features associated with a significantly worsened prognosis. In these cases, EGFR amplification is heterogeneously distributed, mostly in areas with a solid histology

Reactivation of ERK Signaling Causes Resistance to EGFR Kinase Inhibitors

The clinical efficacy of EGFR kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here we show, in multiple complementary models, that resistance to WZ4002 develops through aberrant activation of ERK signaling caused by either an amplification of MAPK1 or by downregulation of negative regulators of ERK signaling. Inhibition of MEK or ERK restores sensitivity to WZ4002 and prevents the emergence of drug resistance. We further identify MAPK1 amplification in an erlotinib resistant EGFR mutant NSCLC patient. In addition, the WZ4002 resistant MAPK1 amplified cells also demonstrate an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rationale combination therapies that should be evaluated in clinical trials

Activation of the PD-1 Pathway Contributes to Immune Escape in EGFR-Driven Lung Tumors

The success in lung cancer therapy with Programmed Death (PD)-1 blockade suggests that immune escape mechanisms contribute to lung tumor pathogenesis. We identified a correlation between Epidermal Growth Factor Receptor (EGFR) pathway activation and a signature of immunosuppression manifested by upregulation of PD-1, PD-L1, cytotoxic T lymphocyte antigen-4 (CTLA-4), and multiple tumor-promoting inflammatory cytokines. We observed decreased cytotoxic T cells and increased markers of T cell exhaustion in mouse models of EGFR-driven lung cancer. PD-1 antibody blockade improved the survival of mice with EGFR-driven adenocarcinomas by enhancing effector T cell function and lowering the levels of tumor-promoting cytokines. Expression of mutant EGFR in bronchial epithelial cells induced PD-L1, and PD-L1 expression was reduced by EGFR inhibitors in non-small cell lung cancer cell lines with activated EGFR. These data suggest that oncogenic EGFR signaling remodels the tumor microenvironment to trigger immune escape, and mechanistically link treatment response to PD-1 inhibition