Integrative and comparative genomic analyses identify clinically relevant pulmonary carcinoid groups and unveil the supra-carcinoids

The worldwide incidence of pulmonary carcinoids is increasing, but little is known about their molecular characteristics. Through machine learning and multi-omics factor analysis, we compare and contrast the genomic profiles of 116 pulmonary carcinoids (including 35 atypical), 75 large-cell neuroendocrine carcinomas (LCNEC), and 66 small-cell lung cancers. Here we report that the integrative analyses on 257 lung neuroendocrine neoplasms stratify atypical carcinoids into two prognostic groups with a 10-year overall survival of 88% and 27%, respectively. We identify therapeutically relevant molecular groups of pulmonary carcinoids, suggesting DLL3 and the immune system as candidate therapeutic targets; we confirm the value of OTP expression levels for the prognosis and diagnosis of these diseases, and we unveil the group of supra-carcinoids. This group comprises samples with carcinoid-like morphology yet the molecular and clinical features of the deadly LCNEC, further supporting the previously proposed molecular link between the low- and high-grade lung neuroendocrine neoplasms.

Molecular screening program to select molecular-based recommended therapies for metastatic cancer patients: analysis from the ProfiLER trial

BACKGROUND

Antitumor activity of molecular-targeted agents is guided by the presence of documented genomic alteration in specific histological subtypes. We aim to explore the feasibility, efficacy and therapeutic impact of molecular profiling in routine setting.

PATIENTS AND METHODS

This multicentric prospective study enrolled adult or pediatric patients with solid or hematological advanced cancer previously treated in advanced/metastatic setting and noneligible to curative treatment. Each molecular profile was established on tumor, relapse or biopsies, and reviewed by a molecular tumor board (MTB) to identify molecular-based recommended therapies (MBRT). The main outcome was to assess the incidence rate of genomic mutations in routine setting, across specific histological types. Secondary objectives included a description of patients with actionable alterations and for whom MBRT was initiated, and overall response rate.

RESULTS

Four centers included 2579 patients from February 2013 to February 2017, and the MTB reviewed the molecular profiles achieved for 1980 (76.8%) patients. The most frequently altered genes were CDKN2A (N = 181, 7%), KRAS (N = 177, 7%), PIK3CA (N = 185, 7%), and CCND1 (N = 104, 4%). An MBRT was recommended for 699/2579 patients (27%), and only 163/2579 patients (6%) received at least one MBRT. Out of the 182 lines of MBRT initiated, 23 (13%) partial responses were observed. However, only 0.9% of the whole cohort experienced an objective response.

CONCLUSION

An MBRT was provided for 27% of patients in our study, but only 6% of patients actually received matched therapy with an overall response rate of 0.9%. Molecular screening should not be used at present to guide decision-making in routine clinical practice outside of clinical trials.This trial is registered with ClinicalTrials.gov, number NCT01774409.

Abstract P6-07-13: New insights on HER2 amplification from the constitutional and somatic standpoints: Results from the ICGC and SIGNAL/Phare studies

Background: HER2-positive (HER2+) breast cancers are defined by the amplification and/or overexpression of the human epidermal growth factor receptor (HER2/ERBB2) gene on chromosome region 17q12. Although anti-HER2 targeted therapies have greatly improved treatment of HER2+ breast cancer, the magnitude of benefit varies widely between patients. Deciphering the genomic and genetic heterogeneity of HER2+ breast cancer may provide a basis to better understand their natural history, opening new avenues of treatment.

Methods: As part of the ICGC Breast Cancer Working Group effort, we combined whole genome sequencing and transcriptomic analyses of 64 HER2+ primary invasive carcinomas, and a genome wide association study (GWAS) of over 9.836 breast cancer patients in the prospective SIGNAL/PHARE cohort (NCT00381901 – RECF1098).

Results: Using WGS data we precisely delineate the ERBB2 amplicon as a 106 kb region involving six genes and show that the amplification mechanism was consistent with breakage-fusion-bridge (BFB) cycles. Four RNA expression-based groups were identified, displaying specific genomic alterations in terms of amplification, rearrangements and mutations. On other hand, GWAS analyses failed to identify any constitutional variants associated with HER2 amplification.

Discussion: By combining whole genome sequencing and expression analysis, we provide evidence showing that HER2+ tumours display considerably more molecular heterogeneity than previously reported. These results are reinforced with the lack of association between any genetic variants and HER2 amplification from GWAS analyses. Taken as a whole, these results suggest that HER2+ breast cancers do not represent per se a homogeneous subtype, but are distributed along the whole breast cancer spectrum, from ER-positive luminal to ER-negative basal phenotype. Genome alterations present in HER2+ tumors are in accordance with these phenotypes, and it is likely that the HER2 amplification is a secondary event in the course of tumorigenesis, not favored by any particular constitutional or somatic genetic variants.

Citation Format: Vincent-Salomon A, Ferrari A, Pivot X, Macgrogan G, Arnould L, Treilleux I, Romieux G, Sertier A-S, Thomas E, Tonon L, Boyault S, Kielbassa J, Letexier V, Pauporte I, Birbaum D, Saintigny P, Cox D, Viari A. New insights on HER2 amplification from the constitutional and somatic standpoints: Results from the ICGC and SIGNAL/Phare studies. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-07-13.

Differential effects of inactivated Axin1 and activated beta-catenin mutations in human hepatocellular carcinomas

Perturbations to the Wnt signaling pathway have been implicated in a large proportion of human hepatocellular carcinomas (HCCs). Activating beta-catenin mutations and loss of function mutations in Axin1 are thought to be functionally equivalent. We examined the Wnt pathway in HCC by comparing the expression of beta-catenin target genes and the level of beta-catenin-dependent transcriptional activation, in 45 HCC tumors and four cell lines. Among these samples, beta-catenin and AXIN1 were mutated in 20 and seven cases, respectively. We found a significant correlation between activated beta-catenin mutations and overexpression of mRNA for the target genes glutamine synthetase (GS), G-protein-coupled receptor (GPR)49 and glutamate transporter (GLT)-1 (P=0.0001), but not for the genes ornithine aminotransferase, LECT2, c-myc and cyclin D1. We also showed that GS is a good immunohistochemical marker of beta-catenin activation in HCC. However, we observed no induction of GS, GPR49 or GLT-1 in the five inactivated Axin1 tumors. Beta-catenin-dependent transcriptional activation in two Axin1-mutated HCC cell lines was much weaker than in beta-catenin-mutated cell lines. Our results strongly suggest that in HCC, contrary to expectation, the loss of function of Axin1 is not equivalent to the gain of function of beta-catenin. Our results also suggest that the tumor suppressor function of Axin1 in HCC may be related to another, non-Wnt pathway.

15-Deoxy-delta12,14-PGJ2, but not troglitazone, modulates IL-1beta effects in human chondrocytes by inhibiting NF-kappaB and AP-1 activation pathways

The activation of peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to inhibit the production and the effects of proinflammatory cytokines. Since interleukin-1beta (IL-1beta) directly mediates cartilage degradation in osteoarthritis, we investigated the capability of PPARgamma ligands to modulate IL-1beta effects on human chondrocytes. RT-PCR and Western blot analysis revealed that PPARgamma expression was decreased by IL-1beta. 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), in contrast to troglitazone, was highly potent to counteract IL-1beta-induced cyclooxygenase-2 and inductible nitric oxide synthase expression, NO production and the decrease in proteoglycan synthesis. Western blot and gel-shift analyses demonstrated that 15d-PGJ2 inhibited NF-kappaB activation, while troglitazone was ineffective. Although 15d-PGJ2 attenuated activator protein-1 binding on the DNA, it potentiated c-jun migration in the nucleus. The absence or the low effect of troglitazone suggests that 15d-PGJ2 action in human chondrocytes is mainly PPARgamma-independent.