Lung squamous cell carcinomas with basaloid histology represent a specific molecular entity.

PURPOSE: The basaloid carcinoma (pure) and the (mixed) basaloid variant of lung squamous cell carcinoma (SCC) have a dismal prognosis but their underlying specific molecular characteristics remain obscure and no therapy has proven to be efficient. EXPERIMENTAL DESIGN: To assess their molecular specificity among other lung SCCs we analyzed DNA copy number aberrations and mRNA expression pangenomic profiles of 93 SCCs, including 42 basaloid samples (24 pure, 18 mixed). RESULTS: Supervised analyses reveal that pure basaloid tumors display a specific mRNA expression profile, encoding factors controlling the cell cycle, transcription, chromatin, and splicing, with prevalent expression in germline and stem cells, while genes related to squamous differentiation are underexpressed. From this signature, we derived a 2-genes (SOX4, IVL) immunohistochemistry-based predictor that discriminated basaloid tumors (pure and mixed) from non-basaloid tumors with 94% accuracy in an independent series. The pure basaloid tumors are also distinguished through unsupervised analyses. Using a centroid-based predictor, the corresponding molecular subtype was found in 8 independent public datasets (n = 58/533), and was shown to be associated with a very poor survival as compared with other SCCs (adjusted HR = 2.45; P = 0.000001). CONCLUSION: This study enlightens the heterogeneity of SCCs that can be subclassified in mRNA expression subtypes. This study demonstrates for the first time that basaloid SCCs constitute a distinct histomolecular entity, which justifies its recognition and distinction from non-basaloid SCCs. In addition, their characteristic molecular profile highlights their intrinsic resistance to cytotoxic chemotherapy and could serve as a guide for targeted therapies.

Prognostic impact of paraneoplastic cushing's syndrome in small-cell lung cancer.

INTRODUCTION: Paraneoplastic Cushing's syndrome (CushingPS) in small-cell lung cancer is rare but severe. METHODS: We studied 383 patients with small-cell lung cancer diagnosed between 1998 and 2012. Among them, 23 patients had CushingPS, 56 had other paraneoplastic syndrome (OtherPS), and 304 had no paraneoplastic syndrome (NoPS). RESULTS: After comparison of the three groups, we observed that CushingPS patients had more extensive disease: 82.6% versus 67.8% versus 53.3% (p = 0.005), respectively, with more than two metastatic sites: 63.2% versus 15.8% and 24.1% (p ≤ 0.001), a higher World Health Organization performance status (2-4): 73.9% versus 57.1% versus 43.7% (p = 0.006), greater weight loss (≥10%): 47.8% versus 33.9% versus 16.4% (p ≤ 0.001), reduced objective response to first-line treatment: 47.6% versus 74.1% versus 71.1% (p = 0.04), and poorer sensitivity to first-line treatment: 19% versus 38.9% versus 48.6% (p = 0.01). NoPS patients, with World Health Organization performance status of 3-4, had extensive disease at diagnosis, with response, sensitivity to first-line treatment, and survival similar to the CushingPS group. At relapse, the CushingPS group had no objective response to second-line treatment versus 25% versus 42.8% in OtherPS and NoPS groups, respectively (p = 0.005). The median survival of CushingPS patients was 6.6 months versus 9.2 months for OtherPS and 13.1 months for NoPS patients (p ≤ 0.001). CushingPS is a prognostic factor of death (hazard ratio, 2.31; p ≤ 0.001). CONCLUSION: CushingPS is the worst form of the paraneoplastic syndromes with particularly extensive tumors. Reduced objective response and sensitivity to first-line treatment and no response to second-line treatment suggest starting palliative care early at first line and exclusively at relapse.

CD74-NRG1 fusions in lung adenocarcinoma.

UNLABELLED: We discovered a novel somatic gene fusion, CD74-NRG1, by transcriptome sequencing of 25 lung adenocarcinomas of never smokers. By screening 102 lung adenocarcinomas negative for known oncogenic alterations, we found four additional fusion-positive tumors, all of which were of the invasive mucinous subtype. Mechanistically, CD74-NRG1 leads to extracellular expression of the EGF-like domain of NRG1 III-ß3, thereby providing the ligand for ERBB2-ERBB3 receptor complexes. Accordingly, ERBB2 and ERBB3 expression was high in the index case, and expression of phospho-ERBB3 was specifically found in tumors bearing the fusion (P < 0.0001). Ectopic expression of CD74-NRG1 in lung cancer cell lines expressing ERBB2 and ERBB3 activated ERBB3 and the PI3K-AKT pathway, and led to increased colony formation in soft agar. Thus, CD74-NRG1 gene fusions are activating genomic alterations in invasive mucinous adenocarcinomas and may offer a therapeutic opportunity for a lung tumor subtype with, so far, no effective treatment. SIGNIFICANCE: CD74­NRG1 fusions may represent a therapeutic opportunity for invasive mucinous lung adenocarcinomas, a tumor with no effective treatment that frequently presents with multifocal unresectable disease.

Ectopic activation of germline and placental genes identifies aggressive metastasis-prone lung cancers.

Activation of normally silent tissue-specific genes and the resulting cell "identity crisis" are the unexplored consequences of malignant epigenetic reprogramming. We designed a strategy for investigating this reprogramming, which consisted of identifying a large number of tissue-restricted genes that are epigenetically silenced in normal somatic cells and then detecting their expression in cancer. This approach led to the demonstration that large-scale "off-context" gene activations systematically occur in a variety of cancer types. In our series of 293 lung tumors, we identified an ectopic gene expression signature associated with a subset of highly aggressive tumors, which predicted poor prognosis independently of the TNM (tumor size, node positivity, and metastasis) stage or histological subtype. The ability to isolate these tumors allowed us to reveal their common molecular features characterized by the acquisition of embryonic stem cell/germ cell gene expression profiles and the down-regulation of immune response genes. The methodical recognition of ectopic gene activations in cancer cells could serve as a basis for gene signature-guided tumor stratification, as well as for the discovery of oncogenic mechanisms, and expand the understanding of the biology of very aggressive tumors.

Outcomes in recurrent small-cell lung cancer after one to four chemotherapy lines: a retrospective study of 300 patients.

Standard treatment of small-cell lung cancer (SCLC) is a combination of etoposide and platinum for patients with extensive disease, associated with radiotherapy for patients with limited disease (LD). Therapeutic strategies for relapse, although well characterized, are disappointing. Between 1997 and 2009, 300 patients were treated for SCLC at Grenoble University Hospital. We analyzed patients' characteristics and outcomes at different treatment steps, to determine prognostic factors and propose subsequent treatment strategies according to "sensitive", "resistant" or "refractory" status established after first-line treatment (L1). The median patient age was 63.2 years, 46.3% had LD, and 23% were female. The objective response rate (ORR) to first-line chemotherapy was 73% [CI(95%): 67.6-77.9] and median survival was 13 months. After L1, comparison between "refractory" and "sensitive" groups showed more extensive disease (76.6% vs. 34.3%, p=0.003), poorer Performance Status (PS 0-1: 48.4% vs. 67.8%, p=0.008), more endocrine paraneoplastic syndrome (18.7% vs. 8.4%, p=0.03) and more composite histology (17.2% vs. 4.9%, p=0.004) in "refractory" patients. After second line (L2), ORR was 55.8% [CI(95%): 45.2-66.0] in "sensitive", 18.2% [CI(95%): 8.2-32.7] in "resistant", and 14.7% [CI(95%): 4.9-31.0] in "refractory" groups; with partial response only for the last two groups. After L3 and L4, ORR was 24.0% [CI(95%): 14.9-35.2] in "sensitive", 9.1% [CI(95%): 11.2-29.2] in "resistant" with partial response only. No response was observed for "refractory". After L1, the median survival was respectively 23, 10 and 6.4 months for "sensitive", "resistant" and "refractory" groups (p<0.001). Multivariate analysis showed that LD and classical SCLC histology were positive predictors of belonging to the "sensitive" group. Positive factors for survival were sensitivity to L1, PS 0-1, LD, Charlson score <4, no endocrine paraneoplastic syndrome and no occupational exposure. Limited disease is the major predictive factor for sensitivity to treatments and survival. Factors linked to the patients' clinical presentation also impact on survival. With currently recommended drugs, the "sensitivity" of the patient determined by the response to L1 indicates that it is pointless to treat "sensitive" with L4, "resistant" with L3 and "refractory" with L2, except for a few selected patients after multidisciplinary group discussion.