Xeroderma pigmentosum group D 751 polymorphism as a predictive factor in resected gastric cancer treated with chemo-radiotherapy

AIM: To evaluate the potential association of xeroderma pigmentosum group D (XPD) codon 751 variant with outcome after chemo-radiotherapy in patients with resected gastric cancer. METHODS: We used PCR-RFLP to evaluate the genetic XPD Lys751Gln polymorphisms in 44 patients with stage III (48%) and IV (20%) gastric cancer treated with surgery following radiation therapy plus 5-fluorouracil/ leucovorin based chemotherapy. RESULTS: Statistical analysis showed that 75% (12 of 16) of relapse patients showed Lys /Lys genotype more frequently (P = 0.042). The Lys polymorphism was an independent predictor of high-risk relapse-free survival from Cox analysis (HR: 3.07, 95% CI: 1.07-8.78, P = 0.036) and Kaplan-Meir test (P = 0.027, log-rank test). CONCLUSION: XPD Lys751Gln polymorphism may be an important marker in the prediction of clinical outcome to chemo-radiotherapy in resected gastric cancer patients

Combining chemotherapy and targeted therapies in metastatic colorectal cancer

Colorectal cancer remains one of the major causes of cancer death worldwide. During the past years, the development of new effective treatment options has led to a considerable improvement in the outcome of this disease. The advent of agents such as capecitabine, irinotecan, oxaliplatin, cetuximab and bevacizumab has translated into median survival times in the range of 2 years. Intense efforts have focused on identifying novel agents targeting specific growth factor receptors, critical signal transduction pathways or mediators of angiogenesis. In addition, several clinical trials have suggested that some of these molecularly targeted drugs can be safely and effectively used in combination with conventional chemotherapy. In this article we review various treatment options combining cytotoxic and targeted therapies currently available for patients with metastatic colorectal cancer

A gene signature of 8 genes could identify the risk of recurrence and progression in Dukes' B colon cancer patients

The benefit of postoperative adjuvant chemotherapy in patients with Dukes' B colorectal cancer is still uncertain and its routine use is not recommended. The five-year relapse rate is approximately 25-40% and the identification of patients at high risk of recurrence would represent an important strategy for the use of adjuvant chemotherapy. We retrospectively analyzed gene expression profiles in frozen tumor specimens from patients with Dukes' B colorectal cancer by using high density oligonucleotide microarrays. Our results show a subset of 48 genes differentially expressed with an associated probability <0.001 in the t-test. Another statistical procedure based on the Fisher criterion resulted in 11 genes able to separate both groups. We selected the 8 genes present in both subsets. The differential expression of five genes (CHD2, RPS5, ZNF148, BRI3 and MGC23401) in colon cancer progression was confirmed by real-time PCR in an independent set of patients of Dukes' B and C stages

Identification by Real-time PCR of 13 mature microRNAs differentially expressed in colorectal cancer and non-tumoral tissues

PURPOSE: Diffuse large B-cell lymphoma (DLBCL) heterogeneity has prompted investigations for new biomarkers that can accurately predict survival. A previously reported 6-gene model combined with the International Prognostic Index (IPI) could predict patients' outcome. However, even these predictors are not capable of unambiguously identifying outcome, suggesting that additional biomarkers might improve their predictive power. EXPERIMENTAL DESIGN: We studied expression of 11 microRNAs (miRNA) that had previously been reported to have variable expression in DLBCL tumors. We measured the expression of each miRNA by quantitative real-time PCR analyses in 176 samples from uniformly treated DLBCL patients and correlated the results to survival. RESULTS: In a univariate analysis, the expression of miR-18a correlated with overall survival (OS), whereas the expression of miR-181a and miR-222 correlated with progression-free survival (PFS). A multivariate Cox regression analysis including the IPI, the 6-gene model-derived mortality predictor score and expression of the miR-18a, miR-181a, and miR-222, revealed that all variables were independent predictors of survival except the expression of miR-222 for OS and the expression of miR-18a for PFS. CONCLUSION: The expression of specific miRNAs may be useful for DLBCL survival prediction and their role in the pathogenesis of this disease should be examined further

Omics approaches in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma, which represents 80% of pancreatic cancers, is mainly diagnosed when treatment with curative intent is not possible. Consequently, the overall five-year survival rate is extremely dismal—around 5% to 7%. In addition, pancreatic cancer is expected to become the second leading cause of cancer-related death by 2030. Therefore, advances in screening, prevention and treatment are urgently needed. Fortunately, a wide range of approaches could help shed light in this area. Beyond the use of cytological or histological samples focusing in diagnosis, a plethora of new approaches are currently being used for a deeper characterization of pancreatic ductal adenocarcinoma, including genetic, epigenetic, and/or proteo-transcriptomic techniques. Accordingly, the development of new analytical technologies using body fluids (blood, bile, urine, etc.) to analyze tumor derived molecules has become a priority in pancreatic ductal adenocarcinoma due to the hard accessibility to tumor samples. These types of technologies will lead us to improve the outcome of pancreatic ductal adenocarcinoma patients

El receptor del factor de crecimiento epitelial EGFR como diana terapéutica en cáncer colorrectal

La terapia dirigida al receptor del factor de crecimiento epitelial o EGFR (Epidermal Growth Factor Receptor) es una novedosa área de investigación clínica que actualmente cuenta con varias moléculas que han demostrado actividad en pacientes con cáncer. Diversos estudios experimentales han relacionado el factor de creci- miento epidérmico (EGF) con el desarrollo y progresión de enfermedad en modelos experimentales de cáncer colorrectal (CCR). Estos hallazgos son sugestivos que CCR puede responder a la terapia dirigida frente a EGFR. La experiencia actual con inhibidores de la tirosina quinasa de EGFR, anticuerpos monoclonales anti EGFR y oligonucleótidos antisentido han demostrado efecto antitumoral y proporciona un fundamento para su evaluación clínica, solos o combinados con drogas citotóxicas. No obstante, son necesarios nuevos estudios y un mayor seguimiento, para confirmar si el actual nivel de entusiasmo se ajustará al impacto terapéutico.Novel targeted therapies which can block the epidermal growth factor receptor (EGFR) have demonstrated activity in the laboratory and in clinical settings. Different agents have been developed and are being tested in cancer patients Studies have shown active single-agent efficacy and efficacy in combination with chemotherapy and/or radiation therapy Some published data have shown that Epidermal Growth Factor (EGF) mediates colorectal cancer growth. These observations suggest anti- EGFR-targeted therapies including anti-EGFR monoclonal antibodies, immunotoxin conjugates, and EGFR tyrosine-kinase inhibitors can play a role in the treatment of colorectal cancer. New studies aimed at blocking this signaling pathway are needed to elucidate the role of these promising new targeted therapies in the treatment of colorectal cancer

Susceptibilidad genética en cáncer de colon

Algunos casos de cáncer presentan una clara causa genética bien definida. Para demostrar la existencia, de forma objetiva, de un cáncer hereditario es necesario identificar la mutación causante en un gen concreto de la línea germinal. La mayoría de los síndromes familiares se transmiten como enfermedades autosómicas dominantes y gran parte de los genes asociados a estos síndromes son genes supresores (APC en el caso de la FAP y MLH1 y MSH2 en el HNPCC). En estos casos hereditarios está recomendado el estudio genético de la familia. Las mutaciones familiares encontradas podrían ayudar a comprender el comportamiento del cáncer.The occurrence of cancer is occasionally explained by genetic alterations. In order to distinguish between a sporadic or hereditary cancer, it becomes necessary to identify a defined mutation on a single gene within the germinal line. Most of the known familial syndromes are autosomic dominant inherited. Frequently, the genes implicated in these disorders are tumor suppressor genes (APC associated with FAP and, MLH1 and MSH2 associated with HNPCC). In the hereditary cases, genetic study of the family is strongly recommended. Moreover, detection of the family mutations could help us understand better the behavior of the cancer

Identification of predictive circulating biomarkers of bevacizumab-containing regimen efficacy in pre-treated metastatic colorectal cancer patients

BACKGROUND: To identify whether circulating levels of angiogenesis-related factors may be predictive of bevacizumab efficacy in pre-treated metastatic colorectal cancer (mCRC) patients. METHODS: Pre-treatment serum levels of 24 cytokines were measured using a multiplex bead assay (MBA) in 32 pre-treated mCRC patients treated with irinotecan plus bevacizumab-based salvage therapy. Macrophage-derived chemokine (MDC), interleukins (ILs) 8 and 6 levels were also validated by enzyme-linked immunosorbent assay (ELISA) at different time points during therapy. RESULTS: Higher epidermal growth factor (EGF) and MDC baseline levels (2.2- and 1.4-fold, respectively) and lower IL-10, IL-6 and IL-8 levels (0.2-, 0.6-, and 0.6-fold, respectively, P<0.05) were observed in patients responding to therapy. Baseline levels of these five serum factors compose a risk signature that may define the subset of patients most likely to benefit from bevacizumab-based therapy in terms of response rate and survival times. A positive correlation was found between MBA and ELISA results (P<0.01). Treatment exposure increased MDC and had opposite effects on IL-8 levels, which were decreased (P<0.05). CONCLUSION: This study suggests that a set of inflammatory and angiogenesis-related serum markers may be associated with the efficacy of bevacizumab-containing regimen

Farmacogenómica en el cáncer colorrectal

La investigación en el proyecto genoma humano va a favorecer en los próximos años el desarrollo farmacoterapias más personalizadas. La Farmacogenómica es una nueva disciplina que se ha desarrollado en los últimos años y cuyos objetivos se dirigen a conocer aquellos mecanismos que permitan explicar cómo la base genética de cada individuo afecta a la respuesta obtenida a las drogas. La posibilidad de predecir qué terapias son más efectivas para un determinado paciente va a constituir una poderosa herramienta médica, particularmente en el ámbito de la oncología. Es probable que estas predic- ciones deriven de una mejor comprensión de la enfermedad tanto a nivel celular como molecular. Por lo que respecta al cáncer colorrectal, los avances en el conocimiento de la etiología de la enfermedad a nivel molecular no se han asociado con una mejora en el tratamiento del paciente. La eficacia clínica y la toxicidad de las drogas más utilizadas en el tratamiento del cáncer colorrectal de cada paciente son por el momento impredecibles. Entre otras muchas variables, se han descrito determinados polimorfismos en genes implicados en el metabolismo de estas drogas que determinan la variabilidad interindividual tanto en la eficacia terapeútica como en la toxicidad. La investigación de las características moleculares del cáncer colorrectal y el desarrollo de nuevas terapias dirigidas a dianas específicas van a permitir en el futuro predecir la respuesta de la neoplasia y, por tanto, modificar la opción terapeútica buscando aquella que mejor se ajuste al perfil biológico.Advances in human genome research will make it possible to personalize pharmacotherapy. Pharmacogenomics has been defined as the study of mechanisms that explain how an individual's genetic inheritance affects the response to drugs. The ability to predict which therapies are most likely to be effective for certain patients would constitute a powerful medical tool, particularly in oncology. Such predictions would be likely to arise from an understanding of the disease on the cellular and molecular level. For colorectal cancer, our increased knowledge of the molecular etiology of the disease has not yet been paralleled by an improvement in patient care. Clinical efficacy and also toxicity of a given chemotherapy are still largely unpredictable for the individual patient. Amongst other variables, genetic polymorphisms determine the interindividual heterogeneity in both toxicity and therapeutic efficacy. Due to the better molecular characterization of colorectal cancer and the development of new target-directed therapies, it should be possible to predict which therapeutic interventions will have a high likelihood of success for an individual patient

Exome-Derived Adiponectin-Associated Variants Implicate Obesity and Lipid Biology

Circulating levels of adiponectin, an adipocyte-secreted protein associated with cardiovascular and metabolic risk, are highly heritable. To gain insights into the biology that regulates adiponectin levels, we performed an exome array meta-analysis of 265,780 genetic variants in 67,739 individuals of European, Hispanic, African American, and East Asian ancestry. We identified 20 loci associated with adiponectin, including 11 that had been reported previously (p .60) spanning as much as 900 kb. To identify potential genes and mechanisms through which the previously unreported association signals act to affect adiponectin levels, we assessed cross-trait associations, expression quantitative trait loci in subcutaneous adipose, and biological pathways of nearby genes. Eight of the nine loci were also associated (p <1 x 10(-4)) with at least one obesity or lipid trait. Candidate genes include PRKAR2A, PTH1R, and HDAC9, which have been suggested to play roles in adipocyte differentiation or bone marrow adipose tissue. Taken together, these findings provide further insights into the processes that influence circulating adiponectin levels.Peer reviewe