Jose Echeveste

Pathological characterization of the glioblastoma border as shown during surgery using 5-aminolevulinic acid-induced fluorescence

Thirty consecutive surgical patients with glioblastoma, were operated upon using fluorescence induced by 5‐aminolevulinic acid as guidance. The fluorescent quality of the tissue was used to take biopsies from the tumor center, from the invasive area around it and from adjacent normal‐looking tissue. These samples were analyzed with HE, Ki‐67 and nestin. Nestin expression in tissue surrounding glioblastoma cases was compared to tissue surrounding vascular lesions, metastasis and hippocampal sclerosis. The rate of gross total resection assessed by volumetric MRI was 83%. Using HE examination as the gold standard, fluorescence identified solid tumor with 100% positive predictive value, invasive areas with 97%, and normal tissue with 67% negative predictive value. Ki67 stained some cells in 69% of the non‐fluorescent samples around the tumor. There was always strong nestin expression around the tumor but it was similar to control cases in non‐glioma lesions with subacute expansion. 5‐aminolevulinic acid fluorescence guidance is very reliable and can help to study the tumor–brain interface. Nestin expression is strong and constant in the tissue around the tumor, but is mostly an acute glial reaction, not specific of the neoplasm. Nestin staining is not recommended as a tumor stem cell marker.

Assessment of Epidermal Growth Factor Receptor and K-Ras Mutation Status in Cytological Stained Smears of Non-Small Cell Lung Cancer Patients: Correlation with Clinical Outcomes

OBJECTIVE Epidermal growth factor receptor (EGFR) and K-ras mutations guide treatment selection in non-small cell lung cancer (NSCLC) patients. Although mutation status is routinely assessed in biopsies, cytological specimens are frequently the only samples available. We determined EGFR and K-ras mutations in cytological samples. METHODS DNA was extracted from 150 consecutive samples, including 120 Papanicolau smears (80%), 10 cell blocks (7%), nine fresh samples (6%), six ThinPrep® tests (4%), and five body cavity fluids (3.3%). Papanicolau smears were analyzed when they had >50% malignant cells. Polymerase chain reaction and direct sequencing of exons 18-21 of EGFR and exon 2 of K-ras were performed. EGFR mutations were simultaneously determined in biopsies and cytological samples from 20 patients. Activity of EGFR tyrosine kinase inhibitors (TKIs) was assessed. RESULTS The cytological diagnosis was adenocarcinoma in 110 samples (73%) and nonadenocarcinoma in 40 (27%) samples. EGFR mutations were identified in 26 samples (17%) and K-ras mutations were identified in 18 (12%) samples. EGFR and K-ras mutations were mutually exclusive. In EGFR-mutated cases, DNA was obtained from stained smears in 24 cases (92%), pleural fluid in one case (4%), and cell block in one case (4%). The response rate to EGFR TKIs in patients harboring mutations was 75%. The mutation status was identical in patients who had both biopsies and cytological samples analyzed. CONCLUSION Assessment of EGFR and K-ras mutations in cytological samples is feasible and comparable with biopsy results, making individualized treatment selection possible for NSCLC patients from whom tumor biopsies are not available.

The Oncoprotein SF2/ASF Promotes Non–Small Cell Lung Cancer Survival by Enhancing Survivin Expression

Purpose: SF2/ASF is a splicing factor recently described as an oncoprotein. In the present work, we examined the role of SF2/ASF in human non–small cell lung cancer (NSCLC) and analyzed the molecular mechanisms involved in SF2/ASF-related carcinogenesis. Experimental Design: SF2/ASF protein levels were analyzed in 81 NSCLC patients by immunohistochemistry. SF2/ASF downregulation cellular models were generated using small interfering RNAs, and the effects on proliferation and apoptosis were evaluated. Survivin and SF2/ASF expression in lung tumors was analyzed by Western blot and immunohistochemistry. Survival curves and log-rank test were used to identify the association between the expression of the proteins and time to progression. Results: Overexpression of SF2/ASF was found in most human primary NSCLC tumors. In vitro downregulation of SF2/ASF induced apoptosis in NSCLC cell lines. This effect was associated with a reduction in the expression of survivin, an antiapoptotic protein widely upregulated in cancer. In fact, SF2/ASF specifically bound survivin mRNA and enhanced its translation, via a mammalian target of rapamycin complex 1 (mTORC1) pathway-dependent mechanism, through the phosphorylation and inactivation of the translational repressor 4E-BP1. Moreover, SF2/ASF promoted the stability of survivin mRNA. A strong correlation was observed between the expression of SF2/ASF and survivin in tumor biopsies from NSCLC patients, supporting the concept that survivin expression levels are controlled by SF2/ASF. Furthermore, combined expression of these proteins was associated with prognosis. Conclusion: This study provides novel data on the mTORC1- and survivin-dependent mechanisms of SF2/ASF-related carcinogenic potential, and shows that SF2/ASF and survivin expression is involved in NSCLC progression. Clin Cancer Res; 16(16); 4113–25. ©2010 AACR.

In vivo identification of an HLA‐G complex as ubiquitinated protein circulating in exosomes

The nonclassical human leukocyte antigen‐G (HLA‐G) is a tolerogenic molecule that can be released to the circulation by expressing cells. This molecule can form dimers but some other complexed HLA‐G forms have been proposed to be present in vivo. Here, we further characterized these other complexed HLA‐G forms in vivo. Ascitic and pleural exudates from patients were selected based on positivity for HLA‐G by ELISA. Complexed HLA‐G was detected in exosomes, which indicates an intracellular origin of these forms. 2D‐PAGE analysis of exudates and isolated exosomes showed that these high molecular weight complexes were more heterogeneous than the HLA‐G1 expressed by cell cultures. Treatment with deglycosylating enzymes did not change the molecular weight of HLA‐G complexes. Immunoblot analysis of exudates and exosomes with an anti‐ubiquitin antibody showed that at least some of these structures correspond to ubiquitinated HLA‐G. HLA‐G ubiquitination could be reproduced in vitro in HLA‐G1‐transfected cell lines, although with a lower modified/nonmodified protein proportion than in exudates. In summary, we demonstrate new circulating HLA‐G forms in vivo that open a new perspective in the study of HLA‐G function and analysis.

EchoBrush may be superior to standard EUS‐guided FNA in the evaluation of cystic lesions of the pancreas

Cystic lesions of the pancreas are being detected with increasing frequency. Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is one of the most precise methods of diagnosis but still has limited accuracy. A new, through‐the‐needle cytologic brush system (EchoBrush; Cook Medical, Bloomington, Ind) has been approved for use during EUS evaluation of cystic pancreatic lesions.

Assessment of EGFR and KRAS mutation status from FNAs and core-needle biopsies of non-small cell lung cancer

Molecular testing to determine gene mutation status is now the recommended standard of care for patients with advanced or metastatic Non‐small cell lung cancer (NSCLC). Because the majority of patients with NSCLC present with metastatic disease, minimally invasive procedures are necessary for diagnosis, staging, and molecular analysis. However, the resulting samples have perceived limitations in the oncology community, and most commercially available tests have not been validated for these sample types. The current study was undertaken to assess the feasibility of determining epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation status in fine‐needle aspirates (FNAs) and core‐needle biopsies (CNBs) after staining with Papanicolaou or hematoxylin and eosin, respectively.

Cribado de cáncer de pulmón: catorce años de experiencia del Programa Internacional de Detección Precoz de Cáncer de Pulmón con TBDR de Pamplona (P-IELCAP)

INTRODUCTION AND OBJECTIVES European experience regarding lung cancer screening using low-dose chest CT (LDCT) is available. However, there is limited data on the Spanish experience in this matter. Our aim is to present the results from the longest ongoing screening program in Spain. METHODOLOGY The Pamplona International Early Lung Cancer Detection Program (P-IELCAP) is actively screening participants for lung cancer using LDCT since year 2000 following the IELCAP protocol, including spirometric assessments. Men and women, ≥40 years of age, current or former smokers with a tobacco history of ≥10 pack-years are included. Results are compared to those from other European trials. RESULTS A total of 2989 participants were screened until March 2014 (73% male). A median of 2 (IQR 1-3) annual screening rounds were performed. Sixty lung cancers were detected in 53 participants (73% in StageI). Adenocarcinoma was the most frequent. The lung cancer prevalence and incidence proportion was 1.0% and 1.4%, respectively, with an annual detection rate of 0.41. The estimated 10-year survival rate among individuals with lung cancer was 70%. Chronic obstructive pulmonary disease and emphysema are important lung cancer predictors. CONCLUSIONS The experience in Spains longest lung cancer screening program is comparable to what has been described in the rest of Europe, and confirms the feasibility and efficacy of lung cancer screening using LDCT.

Identification of Circulating Nonclassic Human Leukocyte Antigen G (HLA-G)–Like Molecules in Exudates

BACKGROUND HLA-G in biological fluids has been proposed to be useful as a tumor marker as both a diagnostic and prognostic factor. Most HLA-G measurement procedures are based on ELISA methods using highly specific antibodies. However, results of published studies are in conflict regarding the clinical utility and even the nature of HLA-G present in circulation. METHODS We collected 118 exudates, 94 from cancer patients and 24 from patients without tumors. We measured HLA-G concentrations by ELISA using MEM-G/9 or G233 as capture antibody. Samples were immunoprecipitated with an anti-HLA-G antibody and analyzed by Western blot using a different anti-HLA-G antibody. RESULTS Discrepancies in HLA-G concentrations in exudates were observed depending on what capture anti-HLA-G antibody was used for ELISA (r = 0.376). These discrepancies were not observed when the ELISAs were performed using culture supernatants from HLA-G1-transfected cells (r = 0.983). Immunoprecipitation and Western blot of cell culture supernatants with 2 different anti-HLA-G antibodies produced the typical band at 39 kDa assigned to HLA-G. When the immunoprecipitation and western blot were performed with exudates, however, there were bands at 53 kDa and 70-76 kDa, higher molecular weights than those usually assigned to HLA-G. These HLA-G-like molecules were associated with β(2)-microglobulin and could also form disulfide bridges with other HLA-G-like molecules. CONCLUSIONS The main HLA-G antigenic molecules in exudates are HLA-G-like complexes, a factor that should be considered when analyzing HLA-G in biological fluids.

Relevance of MIA and S100 serum tumor markers to monitor BRAF inhibitor therapy in metastatic melanoma patients

BRAF V600 mutation has been reported in more than 50% of melanoma cases and its presence predicts clinical activity of BRAF inhibitors (iBRAF). We evaluated the role of MIA, S100 and LDH to monitor iBRAF efficiency in advanced melanoma patients presenting BRAF V600 mutations. This was a prospective study of melanoma patients harboring the BRAF V600 mutation and treated with iBRAF within a clinical trial (dabrafenib) or as part of an expanded access program (vemurafenib). MIA, S100 and LDH were analyzed in serum at baseline, and every 4-6 weeks during treatment. Eighteen patients with melanoma stages IIIc-IV were enrolled with 88.8% of response rate to iBRAF. Baseline concentrations of all the tumor markers correlated with tumor burden. MIA and S100 concentrations decreased significantly one month after the beginning of treatment and, upon progression, their concentrations increased significantly above the minimum levels previously achieved. MIA levels lower than 9 μg/L one month after the beginning of treatment and S100 concentrations lower than 0.1 μg/L at the moment of best response were associated with improved progression-free survival. In conclusion, MIA and S100 are useful to monitor response in melanoma patients treated with iBRAF.

Stratification of resectable lung adenocarcinoma by molecular and pathological risk estimators

BACKGROUND Mortality in early stage, resectable lung cancer is sufficiently high to warrant consideration of post-surgical treatment. Novel markers to stratify resectable lung cancer patients may help with the selection of treatment to improve outcome. METHODS Primary tumour tissue from 485 patients, surgically treated for stage I-II lung adenocarcinoma, was analysed for the RNA expression of 31 cell cycle progression (CCP) genes by quantitative polymerase chain reaction (PCR). The expression average, the CCP score, was combined with pathological stage into a prognostic score (PS). Cox proportional hazards regression assessed prediction of 5-year lung cancer mortality above clinical variables. The PS threshold was tested for risk discrimination by the Mantel-Cox log-rank test. RESULTS The CCP score added significant information above clinical markers (all patients, P=0.0029; stage I patients, P=0.013). The prognostic score was a superior predictor of outcome compared to pathological stage alone (PS, P=0.00084; stage, P=0.24). Five-year lung cancer mortality was significantly different between the low-risk (90%, 95% confidence interval (CI) 81-95%), and high-risk groups (65%, 95% CI 57-72%), P=4.2×10(-6)). CONCLUSIONS The CCP score is an independent prognostic marker in early stage lung adenocarcinoma. The prognostic score provides superior risk estimates than stage alone. The threefold higher risk in the high-risk group defines a subset of patients that should consider therapeutic choices to improve outcome.