MiR-320e is a novel prognostic biomarker in colorectal cancer.

BACKGROUND: Advances in early detection and treatment have improved outcomes in patients with colorectal cancer (CRC). However, there remains a need for robust prognostic and predictive biomarkers. We conducted a systematic discovery and validation of microRNA (miRNA) biomarkers in two clinical trial cohorts of CRC patients. METHODS: We performed an initial 'discovery' phase using Affymetrix miRNA expression arrays to profile stage III CRC patients with and without tumour recurrence (n=50 per group) at 3-years of follow-up. All patients received adjuvant 5-fluorouracil (5-FU) plus oxaliplatin, that is, FOLFOX, treatment. During 'validation', we analysed miRNAs using qRT-PCR in an independent cohort of 237 stage II-IV CRC patients treated with 5-FU-based chemotherapy, as well as in normal colonic mucosa from 20 healthy subjects. Association with disease recurrence, disease-free survival (DFS) and overall survival (OS) was examined using Cox proportional hazard models. RESULTS: In the discovery cohort, miR-320e expression was significantly elevated in stage III colon cancers from patients with vs without recurrence (95% confidence interval (CI)=1.14-1.42; P<0.0001). These results were then independently validated in stage II and III tumours. Specifically, increased miR-320e expression was associated with poorer DFS (hazard ratio (HR)=1.65; 95% CI=1.27-2.13; P=0.0001) and OS (HR=1.78; 95% CI=1.31-2.41; P=0.0003) in stage III CRC patients. CONCLUSIONS: In two clinical trial cohorts, a systematic biomarker discovery and validation approach identified miR-320e to be a novel prognostic biomarker that is associated with adverse clinical outcome in stage III CRC patients treated with 5-FU-based adjuvant chemotherapy. These findings have important implications for the personalised management of CRC patients.

[Sleep-disordered breathing as a consequence of vagus nerve stimulation]. / Alteraciones respiratorias durante el sueño a consecuencia de la estimulación del nervio vago.

INTRODUCTION: Vagus nerve stimulation (VNS) is indicated in cases of refractory epilepsy. Its side effects are frequently minor, however, breathing disturbances during sleep have been previously reported. CASE REPORTS: Our three cases are representative of sleep-disordered breathing that occurred as a consequence of VNS activity in patients with refractory epilepsy. Sleep apnoea was observed in two patients and stridor in one patient. CONCLUSIONS: Given the high prevalence of sleep apnoea-hypopnoea syndrome in patients with refractory epilepsy, implantation of VNS should be ideally preceded by an assessment of the breathing during sleep. Furthermore, sleep-disordered breathing should be considered as a rare complication of VNS, and sleep apnoea should be investigated alongside data regarding VNS firing.

TITLE: Alteraciones respiratorias durante el sueño a consecuencia de la estimulación del nervio vago.Introducción. La estimulación del nervio vago (ENV) es una terapia utilizada en casos de epilepsia refractaria. Sus efectos secundarios son, con frecuencia, leves; sin embargo, se han descrito previamente alteraciones respiratorias durante el sueño. Casos clínicos. Los tres casos incluidos son representativos de alteraciones respiratorias durante el sueño (apnea del sueño y estridor) que surgen a consecuencia de la actividad de la ENV. Conclusiones. Dada la elevada prevalencia del síndrome de apnea/hipopnea durante el sueño en pacientes con epilepsia refractaria, debería estudiarse su posible preexistencia en candidatos a ENV y considerarse su potencial aparición como consecuencia de la ENV en el seguimiento de pacientes con ENV activa.

[Sleep-related movement and behavioural disorders in adults]. / Trastornos del movimiento y de la conducta durante el sueño en el adulto.

Sleep-related movement and behaviour disorders may have an impact on sleep quality and lead to daytime symptoms. These groups of conditions include diseases such as restless legs syndrome, periodic leg movements, and REM and NREM parasomnias. The knowledge of their clinical features and management is of utmost importance for the neurologist and sleep specialist. Frequently, these patients are referred to such specialists and it is relevant to know that certain sleep disorders may be associated with other neurological conditions.

TITLE: Trastornos del movimiento y de la conducta durante el sueño en el adulto.Los trastornos del movimiento y de la conducta durante el sueño pueden tener un impacto en la calidad del sueño del paciente y dar lugar a síntomas diurnos. En estos grupos de enfermedades se incluyen entidades como el síndrome de piernas inquietas, los movimientos periódicos de las piernas y las parasomnias del sueño de movimientos oculares rápidos (REM) y no REM. El conocimiento de sus características clínicas y nociones sobre su manejo es de gran importancia para el neurólogo y especialista en sueño por su frecuencia e impacto en la calidad del sujeto. Con frecuencia, estos pacientes son referidos a dichos especialistas, y es relevante conocer que ciertos trastornos del sueño pueden asociarse a otras enfermedades neurológicas.

Clinically important molecular features of Peruvian colorectal tumours: high prevalence of DNA mismatch repair deficiency and low incidence of KRAS mutations.

BACKGROUND: The incidence of colorectal cancer (CRC) in Peru has been increasing, and no data have been published on the molecular features. We explored the most relevant genetic events involved in colorectal carcinogenesis, with clinical implications. METHODS: Using immunohistochemistry for mismatch-repair (MMR) proteins (MLH1, MSH2, MSH6, and PMS2) and microsatellite instability analysis, we evaluated the status of 90 non-selected CRC Peruvian patients followed in a nationwide reference hospital for cancer (INEN, Lima). Tumours with loss of hMLH1 were evaluated further for hMLH1 promoter hypermethylation and all cases were evaluated for the presence of KRAS and BRAF-V600E mutations. RESULTS: MMR deficiency was found in 35 (38.8%) patients. We identified an unexpected association between MMR deficiency and older age. Among the 14 cases with loss of MLH1, 10 samples exhibited hypermethylation. Of the 90 cases evaluated, 15 (16.7%) carried KRAS mutations; we found one previously unreported mutation (G13R). CONCLUSIONS: Peruvian CRC tumours exhibited the highest prevalence of MMR deficiency reported to date. The expected hereditary component was also high. The age of onset of these MMR deficient tumours was greater than that observed for non-MMR deficient cases, suggesting the ineffectiveness of the Bethesda criteria for Lynch syndrome screening in Peru. Prospective studies are warranted to define the molecular characteristics of CRC in this population.