[Molecular biology of castration resistant prostate cancer.] / Biología molecular del cáncer de próstata resistente a la castración.

OBJECTIVES: Castration resistant prostate cancer (CRPC) is an heterogeneous disease the molecular basis of which we are starting to know in depth. Currently, there are various pathways and targets under study, and probably many others to be characterized. In this paper, we review the most recent knowledge concerning the molecular biology of CRPC with a special focus on the therapeutic application of this knowledge. METHODS: We performed a bibliographic review using PUBMED as the search engine, including the following terms: "Castration resistant prostate cancer", "genomics", "molecular biology", "AR", "WNT", "mTOR", "PTEN", "cell-cycle", "DNA damage repair gene"and "chromatin modifier genes". RESULTS: CRPC has a high load of genetic alterations, probably derived from therapeutic pressure. The most frequent alterations involve the androgen receptor (RA) [60-70%] and the PI3K- AKT-mTOR [40-60%], even though other relevant pathways alterations have been identified such as those relative to cellular cycle [25%], DNA lesion repair genes [20%] and other pathway like WNT-ßcatenin [15-22%]. The knowledge of these pathways is helping as a base for development of new therapeutic targets with promising results and multiple ongoing studies. CONCLUSIONS: Over the last decade, the progress in the knowledge of the molecular bases of CRPC has been very relevant. Even though AR alterations are the most frequent and best characterized, anomalies in other pathways have been also identified as important in the biology of CRPC and derived a notable therapeutic development.

Biología molecular del cáncer de próstata resistente a la castración / Molecular biology of castration resistant prostate cancer

OBJETIVOS: El cáncer de próstata resistente a la castración (CPRC) es una enfermedad heterogénea de la que estamos empezando a conocer sus bases moleculares en profundidad. Hay diversas vías y dianas en estudio en estos momentos y probablemente otras tantas por caracterizar. En este trabajo revisamos los conocimientos mas recientes relativos a la biología molecular del CPRC con un foco especial en la aplicación terapéutica de este conocimiento. Metodos: Se ha llevado a cabo una revisión de la literatura utilizando Pubmed como motor de búsqueda, incluyendo los siguientes términos: "castration-resistant prostate cáncer", "genomics", "molecular biology", "AR", "WNT", "mTOR", "PTEN", "cell-cycle", "DNA damage repair gene" y "chromatin modifier genes". RESULTADOS: El CPRC tiene una alta carga de alteraciones genéticas, probablemente derivadas de la presión terapéutica. Las alteraciones más frecuentes afectan al receptor androgénico (RA) [60-70%] y a la vía de PI3K-AKT-mTOR [40-60%], si bien se han identificado alteraciones relevantes de otras vías como aquellas relativas al control del ciclo celular [25%], en genes de reparación de lesiones en el ADN [20%] y en otras vías como la de WNT-betacatenina [15-22%]. El conocimiento de estas alteraciones esta sirviendo como base para el desarrollo de terapias especificas a nuevas dianas terapéuticas con resultados prometedores y multiples estudios en curso. CONCLUSIONES: En la ultima década el avance en el conocimiento de las bases moleculares del CPRC ha sido muy relevante. Si bien las alteraciones del RA son las mas frecuentes y mejor caracterizadas, anomalías en otras vías han sido también identificadas como destacadas en la biología del CRPC y han derivado en un desarrollo terapéutico notable

OBJECTIVES: Castration resistant prostate cancer (CRPC) is an heterogeneous disease the molecular basis of which we are starting to know in depth. Currently, there are various pathways and targets under study, and probably many others to be characterized. In this paper, we review the most recent knowledge concerning the molecular biology of CRPC with a special focus on the therapeutic application of this knowledge. METHODS: We performed a bibliographic review using PUBMED as the search engine, including the following terms: "Castration resistant prostate cancer", "genomics", "molecular biology", "AR", "WNT", "mTOR", "PTEN", cell-cycle", "DNA damage repair gene" and "chromatin modifier genea". RESULTS: CRPC has a high load of genetic alterations, probably derived from therapeutic pressure. The most frequent alterations involve the androgen receptor (RA) [60-70%] and the PI3K- AKT-mTOR [40-60%], even though other relevant pathways alterations have been identified such as those relative to cellular cycle [25%], DNA lesion repair genes [20%] and other pathway like WNT-Betacatenin [15-22%]. The knowledge of these pathways is helping as a base for development of new therapeutic targets with promising results and multiple ongoing studies. CONCLUSIONS: Over the last decade, the progress in the knowledge of the molecular bases of CRPC has been very relevant. Even though AR alterations are the most frequent and best characterized, anomalies in other pathways have been also identified as important in the biology of CRPC and derived a notable therapeutic development

Combinatory effect of BRCA1 and HERC2 expression on outcome in advanced non-small-cell lung cancer.

BACKGROUND: BRCA1 is a main component of homologous recombination and induces resistance to platinum in preclinical models. It has been studied as a potential predictive marker in lung cancer. Several proteins modulate the function of BRCA1. The E3 ubiquitin ligase HERC2 facilitates the assembly of the RNF8-UBC13 complex to recruit BRCA1 to DNA damage sites. The combined analysis of multiple components of the pathway leading to the recruitment of BRCA1 at DNA damage sites has the potentiality to improve the BRCA1 predictive model. METHODS: We retrospectively analyzed 71 paraffin-embedded tumor samples from advanced non-small-cell lung cancer patients treated with first-line platinum based chemotherapy and measured the mRNA expression levels of BRCA1, RNF8, UBC13 and HERC2 using real-time PCR. The mRNA expression was categorized using median value as cut-off point. RESULTS: The median progression-free survival of all 71 patients was 7.2 months whereas the median overall survival of the study population was 10.7 months. Among patients with low BRCA1 expression, the median PFS was 7.4 months in the presence of low HERC2 levels and 5.9 months for patients expressing high HERC2 levels (p = 0.01). The median OS was 15.3 months for patients expressing low levels of both genes and 7.4 months for those with low BRCA1 but high HERC2 (p = 0.008). The multivariate analysis showed that among patients with Eastern Cooperative Oncology Group performance status 0-1, the combined low expression of both BRCA1 and HERC2 clearly reduced the risk of progression (p = 0.03) and of death (p = 0.004). CONCLUSIONS: These findings confirm the potentiality of integrated DNA repair components analysis in predicting the sensitivity to platinum in lung cancer. The study indicates a predictive role for HERC2 mRNA expression and paves the way for further refinement of the BRCA1 predictive model.

Pharmacogenetics and pharmacogenomics as tools in cancer therapy.

Pharmacogenetics and pharmacogenomics (PGx) are rapidly growing fields that aim to elucidate the genetic basis for the interindividual differences in drug response. PGx approaches have been applied to many anticancer drugs in an effort to identify relevant inherited or acquired genetic variations that may predict patient response to chemotherapy and targeted therapies. In this article, we discuss the advances in the field of cancer pharmacogenetics and pharmacogenomics, driven by the recent technological advances and new revolutionary massive sequencing technologies and their application to elucidate the genetic bases for interindividual drug response and the development of biomarkers able to personalize drug treatments. Specifically, we present recent progress in breast cancer molecular classifiers, cell-free circulating DNA as a prognostic and predictive biomarker in cancer, patient-derived tumor xenograft models, chronic lymphocytic leukemia genomic landscape, and current pharmacogenetic advances in colorectal cancer. This review is based on the lectures presented by the speakers of the symposium "Pharmacogenetics and Pharmacogenomics as Tools in Cancer Therapy" from the VII Conference of the Spanish Pharmacogenetics and Pharmacogenomics Society (SEFF), held in Madrid (Spain) on April 21, 2015.

Carcinosarcoma of the upper urinary tract with an aggressive angiosarcoma component.

Carcinosarcomas (CS) are biphasic tumors with malignant epithelial and mesenchymal elements. The sarcomatoid elements of CS can include chondrosarcoma, malignant fibrous histiocytoma, osteosarcoma, leiomyosarcoma, fibrosarcoma, or liposarcoma. CS of the upper urinary tract are extremely rare but are associated with a poor prognosis. We report a case of a 44-year-old man with a localized right renal pelvis mass treated with a right nephroureterectomy. The pathological examination showed a high-grade urothelial carcinoma of the renal pelvis, stage III (pT3aNxM0). A few days later, he developed lower back pain, hematuria, cough with hemoptoic sputum and progressive dyspnea. Radiological explorations showed multiple bilateral lung nodules and a retroperitoneal mass. A CT-guided biopsy of the retroperitoneal mass revealed a high-grade angiosarcoma. A review of the nephrectomy specimen showed a microscopic focus of angiosarcoma in the urothelial carcinoma. Therefore, the initial diagnosis was changed to CS of the renal pelvis with an angiosarcoma component. The patient developed progressive respiratory failure and died 8 weeks after surgery. An autopsy revealed a large retroperitoneal mass with metastatic nodules to the abdominal wall, diaphragm, small intestine, liver, spleen, and lung. All lesions were angiosarcoma, with no evidence of urothelial carcinoma. This is the first case reported of a patient with CS of the upper urinary tract with an angiosarcoma component with a very aggressive course that caused the immediate appearance of multiple angiosarcoma metastases. We also describe the clinical and molecular characteristics of CS, which will help to contribute to a better understanding of this type of tumor.

Novel therapeutic strategies for patients with NSCLC that do not respond to treatment with EGFR inhibitors.

INTRODUCTION: Treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) yields tumour responses in non-small cell lung cancer (NSCLC) patients harbouring activating EGFR mutations. However, even in long-lasting responses, resistance to EGFR TKIs invariably occurs. AREAS COVERED: This review examines resistance mechanisms to EGFR TKI treatment, which mainly arise from secondary EGFR mutations. Other resistance-inducing processes include mesenchymal-epithelial transition factor (MET) amplification, epithelial-mesenchymal transformation, phenotypic change from NSCLC to small-cell lung carcinoma, and modifications in parallel signalling pathways. Current therapeutic strategies to overcome these EGFR TKI resistance mechanisms focus on the inhibition or blocking of multiple members of the ErbB family. Several molecules which target multiple ErbB receptors are being investigated in NSCLC and other indications including afatinib, an ErbB Family Blocker, as well as dacomitinib and lapatinib. Novel, non-quinazoline, EGFR inhibitors, that also target EGFR activating and resistance (T790M) mutations, are currently under clinical development. Other therapeutic strategies include inhibition of parallel and downstream pathways, using agents which target heat shock protein (HSP)90 or poly (ADP-ribose) polymerase in addition to mammalian target of rapamycin (mTOR), monoclonal antibodies against the insulin-like growth factor-1 receptor, and fulvestrant-mediated oestrogen receptor regulation. CONCLUSION: Improved understanding of mechanisms underlying resistance to EGFR TKIs emphasises the importance of a genotype-guided approach to therapy. Elucidation of resistance mechanisms is indeed crucial to target innovative therapeutic approaches and to improve the efficacy of anticancer regimes in NSCLC.

Clinical validation of a PCR assay for the detection of EGFR mutations in non-small-cell lung cancer: retrospective testing of specimens from the EURTAC trial.

The EURTAC trial demonstrated that the tyrosine kinase inhibitor (TKI) erlotinib was superior to chemotherapy as first-line therapy for advanced non-small cell lung cancers (NSCLC) that harbor EGFR activating mutations in a predominantly Caucasian population. Based on EURTAC and several Asian trials, anti-EGFR TKIs are standard of care for EGFR mutation-positive NSCLC. We sought to validate a rapid multiplex EGFR mutation assay as a companion diagnostic assay to select patients for this therapy. Samples from the EURTAC trial were prospectively screened for EGFR mutations using a combination of laboratory-developed tests (LDTs), and tested retrospectively with the cobas EGFR mutation test (EGFR PCR test). The EGFR PCR test results were compared to the original LDT results and to Sanger sequencing, using a subset of specimens from patients screened for the trial. Residual tissue was available from 487 (47%) of the 1044 patients screened for the trial. The EGFR PCR test showed high concordance with LDT results with a 96.3% overall agreement. The clinical outcome of patients who were EGFR-mutation detected by the EGFR PCR test was very similar to the entire EURTAC cohort. The concordance between the EGFR PCR test and Sanger sequencing was 90.6%. In 78.9% of the discordant samples, the EGFR PCR test result was confirmed by a sensitive deep sequencing assay. This retrospective study demonstrates the clinical utility of the EGFR PCR test in the accurate selection of patients for anti-EGFR TKI therapy. The EGFR PCR test demonstrated improved performance relative to Sanger sequencing.

Phase I/II trial of vorinostat (SAHA) and erlotinib for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations after erlotinib progression.

OBJECTIVES: Vorinostat or suberoylanilide hydroxamic acid (SAHA) is a novel histone deacetylase inhibitor with demonstrated antiproliferative effects due to drug-induced accumulation of acetylated proteins, including the heat shock protein 90. We prospectively studied the activity of vorinostat plus erlotinib in EGFR-mutated NSCLC patients with progression to tyrosine kinase inhibitors. PATIENTS AND METHODS: We conducted this prospective, non-randomized, multicenter, phase I/II trial to evaluate the maximum tolerated dose, toxicity profile and efficacy of erlotinib and vorinostat. Patients with advanced NSCLC harboring EGFR mutations and progressive disease after a minimum of 12 weeks on erlotinib were included. The maximum tolerated dose of vorinostat plus erlotinib was used as recommended dose for the phase II (RDP2) to assess the efficacy of the combination. The primary end point was progression-free-survival rate at 12 weeks (PFSR12w). Pre-treatment plasma samples were required to assess T790M resistant mutation. RESULTS: A total of 33 patients were enrolled in the phase I-II trial. The maximum tolerated dose was erlotinib 150 mg p.o., QD, and 400mg p.o., QD, on days 1-7 and 15-21 in a 28-day cycle. Among the 25 patients treated at the RDP2, the most common toxicities included anemia, fatigue and diarrhea. No responses were observed. PFSR12w was 28% (IC 95%: 18.0-37.2); median progression-free survival (PFS) was 8 weeks (IC 95%: 7.43-8.45) and overall survival (OS) 10.3 months (95% CI: 2.4-18.1). CONCLUSION: Full dose of continuous erlotinib with vorinostat 400mg p.o., QD on alternative weeks can be safely administered. Still, the combination has no meaningful activity in EGFR-mutated NSCLC patients after TKI progression.

The impact of EGFR T790M mutations and BIM mRNA expression on outcome in patients with EGFR-mutant NSCLC treated with erlotinib or chemotherapy in the randomized phase III EURTAC trial.

PURPOSE: Concomitant genetic alterations could account for transient clinical responses to tyrosine kinase inhibitors of the EGF receptor (EGFR) in patients harboring activating EGFR mutations. EXPERIMENTAL DESIGN: We have evaluated the impact of pretreatment somatic EGFR T790M mutations, TP53 mutations, and Bcl-2 interacting mediator of cell death (BCL2L11, also known as BIM) mRNA expression in 95 patients with EGFR-mutant non-small-cell lung cancer (NSCLC) included in the EURTAC trial (trial registration: NCT00446225). RESULTS: T790M mutations were detected in 65.26% of patients using our highly sensitive method based on laser microdissection and peptide-nucleic acid-clamping PCR, which can detect the mutation at an allelic dilution of 1 in 5,000. Progression-free survival (PFS) to erlotinib was 9.7 months for those with T790M mutations and 15.8 months for those without, whereas among patients receiving chemotherapy, it was 6 and 5.1 months, respectively (P < 0.0001). PFS to erlotinib was 12.9 months for those with high and 7.2 months for those with low/intermediate BCL2L11 expression levels, whereas among chemotherapy-treated patients, it was 5.8 and 5.5 months, respectively (P = 0.0003). Overall survival was 28.6 months for patients with high BCL2L11 expression and 22.1 months for those with low/intermediate BCL2L11 expression (P = 0.0364). Multivariate analyses showed that erlotinib was a marker of longer PFS (HR = 0.35; P = 0.0003), whereas high BCL2L11 expression was a marker of longer PFS (HR = 0.49; P = 0.0122) and overall survival (HR = 0.53; P = 0.0323). CONCLUSIONS: Low-level pretreatment T790M mutations can frequently be detected and can be used for customizing treatment with T790M-specific inhibitors. BCL2L11 mRNA expression is a biomarker of survival in EGFR-mutant NSCLC and can potentially be used for synthetic lethality therapies.

The predictive value of 53BP1 and BRCA1 mRNA expression in advanced non-small-cell lung cancer patients treated with first-line platinum-based chemotherapy.

Platinum-based chemotherapy is the standard first-line treatment for non-oncogene- addicted non-small cell lung cancers (NSCLCs) and the analysis of multiple DNA repair genes could improve current models for predicting chemosensitivity. We investigated the potential predictive role of components of the 53BP1 pathway in conjunction with BRCA1. The mRNA expression of BRCA1, MDC1, CASPASE3, UBC13, RNF8, 53BP1, PIAS4, UBC9 and MMSET was analyzed by real-time PCR in 115 advanced NSCLC patients treated with first-line platinum-based chemotherapy. Patients expressing low levels of both BRCA1 and 53BP1 obtained a median progression-free survival of 10.3 months and overall survival of 19.3 months, while among those with low BRCA1 and high 53BP1 progression-free survival was 5.9 months (P less than 0.0001) and overall survival was 8.2 months (P=0.001). The expression of 53BP1 refines BRCA1-based predictive modeling to identify patients most likely to benefit from platinum-based chemotherapy.

A prognostic DNA methylation signature for stage I non-small-cell lung cancer.

PURPOSE: Non-small-cell lung cancer (NSCLC) is a tumor in which only small improvements in clinical outcome have been achieved. The issue is critical for stage I patients for whom there are no available biomarkers that indicate which high-risk patients should receive adjuvant chemotherapy. We aimed to find DNA methylation markers that could be helpful in this regard. PATIENTS AND METHODS: A DNA methylation microarray that analyzes 450,000 CpG sites was used to study tumoral DNA obtained from 444 patients with NSCLC that included 237 stage I tumors. The prognostic DNA methylation markers were validated by a single-methylation pyrosequencing assay in an independent cohort of 143 patients with stage I NSCLC. RESULTS: Unsupervised clustering of the 10,000 most variable DNA methylation sites in the discovery cohort identified patients with high-risk stage I NSCLC who had shorter relapse-free survival (RFS; hazard ratio [HR], 2.35; 95% CI, 1.29 to 4.28; P = .004). The study in the validation cohort of the significant methylated sites from the discovery cohort found that hypermethylation of five genes was significantly associated with shorter RFS in stage I NSCLC: HIST1H4F, PCDHGB6, NPBWR1, ALX1, and HOXA9. A signature based on the number of hypermethylated events distinguished patients with high- and low-risk stage I NSCLC (HR, 3.24; 95% CI, 1.61 to 6.54; P = .001). CONCLUSION: The DNA methylation signature of NSCLC affects the outcome of stage I patients, and it can be practically determined by user-friendly polymerase chain reaction assays. The analysis of the best DNA methylation biomarkers improved prognostic accuracy beyond standard staging.

EGFR mutation analysis in sputum of lung cancer patients: a multitechnique study.

OBJECTIVES: Epidermal growth factor receptor (EGFR) mutations have been identified in lung adenocarcinomas and are associated with high response chance to EGFR tyrosine kinase inhibitors. EGFR mutations can be detected in tumour tissue, cytology specimens and blood from lung cancer patients. Thus far, EGFR mutation analysis has not been systematically demonstrated for sputum samples. The aim of the present study was to determine whether EGFR mutation analysis is attainable on sputum samples, employing different assays in a multicenter study. MATERIALS AND METHODS: Sputum DNA from 10 lung cancer patients with confirmed EGFR mutation in their tumour tissue, 10 lung cancer patients without evidence of an EGFR mutation, and 10 patients with chronic obstructive pulmonary disease (COPD) was used for mutation analysis by Cycleave PCR, COLD-PCR, PangaeaBiotech SL Technology (PST), and High Resolution Melting, respectively. Targeted resequencing (TruSeq Amplicon Cancer Panel) and droplet digital PCR were additionally performed on the 10 samples with EGFR mutation. RESULTS: Dependent on the assay, EGFR mutations could be detected in 30-50% of the sputum samples of patients with EGFR mutations. The different techniques revealed consistent results, with slightly higher sensitivity for PST. Neither the lung cancer patients without EGFR mutation nor the COPD controls tested positive for EGFR mutations in their sputum samples, indicating high clinical specificity of all assays. CONCLUSION: EGFR mutations can be detected in sputum samples from patients with EGFR-mutated non-small cell lung cancer, which may replace biopsy procedure for some patients.

Cross-validation analysis of the prognostic significance of mucin expression in patients with resected non-small cell lung cancer treated with adjuvant chemotherapy: results from IALT, JBR.10 and ANITA.

INTRODUCTION: CALGB 9633 was a randomized trial of observation versus adjuvant chemotherapy for patients with stage IB non-small cell lung cancer (NSCLC). In CALGB 9633, the presence of mucin in the primary tumor was associated with shorter disease-free survival (DFS; hazard ratio (HR) = 1.9, p = 0.002) and overall survival (OS; HR = 1.9, p = 0.004). METHODS: To validate these results, mucin staining was performed on primary tumor specimens from 780 patients treated on IALT, 351 on JBR.10 and 150 on ANITA. The histochemical technique using mucicarmine was performed. The prognostic value of mucin for DFS and OS was tested in a Cox model stratified by trial and adjusted for clinical and pathological factors. A pooled analysis of all 4 trials was performed for the predictive value of mucin for benefit from adjuvant chemotherapy. RESULTS: The cross-validation group had 48% squamous, 37% adenocarcinoma and 15% other NSCLC compared with 29%, 56%, and 15%, respectively in CALGB. Among 1262 patients with assessable results, mucin was positive in IALT 24%, JBR.10 30%, ANITA 22% compared with 45% in CALGB. Histology was the only significant covariate (p < 0.0001) in multivariate analysis with mucin seen more commonly in adenocarcinoma (56%) compared with squamous (5%) and other NSCLC (15%). Mucin was a borderline negative prognostic factor for DFS (HR = 1.2 [1.0-1.5], p = 0.06) but not significantly so for OS (HR=1.1 [0.9-1.4], p = 0.25). Prognostic value did not vary according to histology: HR = 1.3 [1.0-1.6] in adenocarcinoma vs. 1.6 [1.2-2.2] for DFS in other histology (interaction p = 0.69). Mucin status was not predictive for benefit from adjuvant chemotherapy (test of interaction: DFS p = 0.27; OS p = 0.49). CONCLUSIONS: Mucin was less frequent in the cross-validation group due to its higher percentage of squamous cell carcinomas. The negative impact of mucin was confirmed for DFS but not for OS. Mucin expression was not predictive of overall survival benefit from adjuvant chemotherapy.

Main histologic types of non-small-cell lung cancer differ in expression of prognosis-related genes.

BACKGROUND: There is increasing evidence that suggests that particular histopathologic types of non-small-cell lung cancer (NSCLC) display distinct molecular characteristics. We analyzed, in lung squamous cell carcinoma (SCC) and adenocarcinoma (AC), the expression of 8 genes that constitute 2 previously reported prognostic expression signatures in NSCLC. METHODS: Fresh-frozen tumor and normal lung samples were obtained at surgery from 135 patients with stage I-III NSCLC (89 (65.9%) SCC, 46 (34.1%) AC). Expression of CSF1 (colony stimulating factor for macrophages), carbonic anhydrase 9 (CA9), epithelial growth factor receptor (EGFR), dual specificity phosphatase 6 (DUSP6), v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (ERBB3), monocyte to macrophage differentiation-associated (MMD), lymphocyte-specific protein tyrosine kinase (LCK) and signal transducer and activator of transcription 1 (STAT1) was assessed in SCC, AC, and in normal lung by quantitative reverse transcriptase - polymerase chain reaction (qRT-PCR). Metastasis-free survival was analyzed according to the median value of gene expression in the entire NSCLC cohort and separately in SCC and AC. RESULTS: Expression of CA9, CSF1, DUSP6, STAT1, and MMD differed between NSCLC and normal lung. EGFR was more abundant in SCC compared with AC, whereas the reverse was true for DUSP6 and ERBB3. A high expression of CSF1 correlated with shorter metastasis-free survival in the entire NSCLC group (P = .016) and in SCC (P = .049) and AC (P = .034) cohorts. CONCLUSIONS: Several genes considered prognostic in NSCLC showed significantly different expression in SCC and AC, and thus should be analyzed separately in these 2 subtypes for their prognostic significance. CSF1 is similarly expressed in SCC and AC, and portends a poor outcome in the entire group of patients with NSCLC, and in SCC and AC when considered separately.

Treatment and detection of ALK-rearranged NSCLC.

The recent approval of crizotinib for the treatment of anaplastic lymphoma kinase (ALK)-rearranged advanced non-small cell lung cancer (NSCLC) in the US and other countries has provoked intense interest in ALK rearrangements as oncogenic drivers, and promises to revolutionise the way in which NSCLC is diagnosed and treated. Here, we review clinical data to date for the use of crizotinib to treat patients with advanced, ALK-positive NSCLC and consider issues surrounding the detection of ALK-positivity including the use of fluorescence in situ hybridisation and the other potential techniques available, and their suitability for ALK screening. We also discuss the emergence of resistance to crizotinib therapy and the range of other ALK inhibitors currently in development.

CK-coated magnetic-based beads as a tool to isolate circulating tumor cells (CTCs) in human tumors.

Circulating tumor cells (CTCs) can be detected in the blood of many cancer patients and play a key role in metastasis. In addition, after the development of technologies with the necessary sensitivity and reproducibility, the diagnostic potential of these cells is being actively explored. Recently, the U.S. Food and Drug Administration has approved the CellSearch(®) System, based on magnetic beads coated with epithelial cell-adhesion molecule (EpCAM) antibody. Despite its usefulness, this system can miss CTCs that lose epithelial antigens due to the epithelial-mesenchymal transition and, in the case of advanced NSCLC, CTCs positivity can be demonstrated only in 30-50% of patients. In an effort to overcome these drawbacks, new methods are being developed. In this study, we have evaluated CK-coated beads as a system to isolate CTCs from lung cancer patients in the clinical setting, and have evaluated if they can be a useful source of material for genetic testing. We were able to identify CTCs in 17 of the 30 patients included in the study (57%), with a range of 1 to 7 cells. In two of them, we found only CTCs with an EMT pattern. CTC positivity seemed to correlate with the clinical history of the malignancy. CTCs could be detected in more than 80% of stage III-IV lung cancer patients at presentation or in blood samples taken immediately after surgery. The percentage dropped to 13% in patients responding to chemotherapy or TKIs, raising again to 57% after tumor progression. Finally, we tested the CTCs isolated from 8 patients for EGFR and k-ras mutations, but gene amplification was successful only in the 3 patients with 4 or more CTCs.

Guideline on the requirements of external quality assessment programs in molecular pathology.

Molecular pathology is an integral part of daily diagnostic pathology and used for classification of tumors, for prediction of prognosis and response to therapy, and to support treatment decisions. For these reasons, analyses in molecular pathology must be highly reliable and hence external quality assessment (EQA) programs are called for. Several EQA programs exist to which laboratories can subscribe, but they vary in scope, number of subscribers, and execution. The guideline presented in this paper has been developed with the purpose to harmonize EQA in molecular pathology. It presents recommendations on how an EQA program should be organized, provides criteria for a reference laboratory, proposes requirements for EQA test samples, and defines the number of samples needed for an EQA program. Furthermore, a system for scoring of the results is proposed as well as measures to be taken for poorly performing laboratories. Proposals are made regarding the content requirements of an EQA report and how its results should be communicated. Finally, the need for an EQA database and a participant manual are elaborated. It is the intention of this guideline to improve EQA for molecular pathology in order to provide more reliable molecular analyses as well as optimal information regarding patient selection for treatment.

Randomized, phase III study of gemcitabine or erlotinib maintenance therapy versus observation, with predefined second-line treatment, after cisplatin-gemcitabine induction chemotherapy in advanced non-small-cell lung cancer.

PURPOSE: This phase III study investigated whether continuation maintenance with gemcitabine or switch maintenance with erlotinib improves clinical outcome compared with observation in patients with advanced non-small-cell lung cancer (NSCLC) whose disease was controlled after cisplatin-gemcitabine induction chemotherapy. PATIENTS AND METHODS: Four hundred sixty-four patients with stage IIIB/IV NSCLC without tumor progression after four cycles of cisplatin-gemcitabine were randomly assigned to observation or to gemcitabine (1,250 mg/m(2) days 1 and 8 of a 3-week cycle) or daily erlotinib (150 mg/day) study arms. On disease progression, patients in all three arms received pemetrexed (500 mg/m(2) once every 21 days) as predefined second-line therapy. The primary end point was progression-free survival (PFS). RESULTS: PFS was significantly prolonged by gemcitabine (median, 3.8 v 1.9 months; hazard ratio [HR], 0.56; 95% CI, 0.44 to 0.72; log-rank P < .001) and erlotinib (median, 2.9 v 1.9 months; HR, 0.69; 95% CI, 0.54 to 0.88; log-rank P = .003) versus observation; this benefit was consistent across all clinical subgroups. Both maintenance strategies resulted in a nonsignificant improvement in overall survival (OS); patients who received second-line pemetrexed or with a performance status of 0 appeared to derive greater benefit. Exploratory analysis showed that magnitude of response to induction chemotherapy may affect the OS benefit as a result of gemcitabine maintenance. Maintenance gemcitabine and erlotinib were well tolerated with no unexpected adverse events. CONCLUSION: Gemcitabine continuation maintenance or erlotinib switch maintenance significantly reduces disease progression in patients with advanced NSCLC treated with cisplatin-gemcitabine as first-line chemotherapy. Response to induction chemotherapy may affect OS only for continuation maintenance.