Endolaparoscopic removal of colonic polyps

AIM

A proportion of colonic polyps is not amenable to exclusively colonoscopic removal due to their location, size or tortuosity of the colon. A combined laparoscopic/colonoscopic polypectomy or endolaparoscopic polypectomy (ELP) is an alternative to formal segmental resection. We present our experience of ELP.

METHOD

This is a retrospective review of a consecutive series of patients who underwent ELP for preoperatively diagnosed benign polyps between 2010 and 2013. Data are presented as median (interquartile range, IQR).

RESULTS

Thirty patients commenced ELP. Eighteen were male and the median (IQR) age was 65.4 (61.6-73.5) years. Of 30 attempted cases, 22 (73%) underwent successful ELP surgery. Patients in whom combined ELP surgery was unsuccessful were converted to laparoscopic colectomy (one) or colonic mobilization and colotomy (seven). The median operation time for successful ELP was 105 (75-125) min. The complication rate was 13.3% and the median length of stay was 2.0 (1.0-3.0) days for successful ELP compared with 5.5 (3.5-6.8) days for converted patients (P = 0.014). The median polyp size was 14 (10-22) mm; eight (26.7%) had high-grade dysplasia with two cases of invasive cancer identified.

CONCLUSION

A combined endoscopic-laparoscopic approach provides an alternative to segmental resection for treating challenging colonic polyps. This approach appears to be safe and effective and should be offered to selected patients with benign colonic polyps.

Frequent germline deleterious mutations in DNA repair genes in familial prostate cancer cases are associated with advanced disease

BACKGROUND

Prostate cancer (PrCa) is one of the most common diseases to affect men worldwide and among the leading causes of cancer-related death. The purpose of this study was to use second-generation sequencing technology to assess the frequency of deleterious mutations in 22 tumour suppressor genes in familial PrCa and estimate the relative risk of PrCa if these genes are mutated.

METHODS

Germline DNA samples from 191 men with 3 or more cases of PrCa in their family were sequenced for 22 tumour suppressor genes using Agilent target enrichment and Illumina technology. Analysis for genetic variation was carried out by using a pipeline consisting of BWA, Genome Analysis Toolkit (GATK) and ANNOVAR. Clinical features were correlated with mutation status using standard statistical tests. Modified segregation analysis was used to determine the relative risk of PrCa conferred by the putative loss-of-function (LoF) mutations identified.

RESULTS

We discovered 14 putative LoF mutations in 191 samples (7.3%) and these mutations were more frequently associated with nodal involvement, metastasis or T4 tumour stage (P=0.00164). Segregation analysis of probands with European ancestry estimated that LoF mutations in any of the studied genes confer a relative risk of PrCa of 1.94 (95% CI: 1.56-2.42).

CONCLUSIONS

These findings show that LoF mutations in DNA repair pathway genes predispose to familial PrCa and advanced disease and therefore warrants further investigation. The clinical utility of these findings will become increasingly important as targeted screening and therapies become more widespread.

Clopidogrel hyper-response and bleeding risk in neurointerventional procedures

BACKGROUND AND PURPOSE

Antiplatelet therapy is associated with decreased ischemic events after neurointerventional procedures. Antiplatelet resistance negates the protective effects of antiplatelet medication, leading to a higher incidence of ischemic events. A possible link between antiplatelet hyper-response and increased hemorrhagic complications has been inadequately investigated. We aimed to examine the correlation between antiplatelet hyper-response and the risk of hemorrhagic complications.

MATERIALS AND METHODS

Patients who were treated with antiplatelet medications and underwent neurointerventional procedures were prospectively recruited. We collected the following data: demographics, vascular risk factors, antiplatelet and anticoagulation treatment, antiplatelet responsiveness, coagulation profile, and hemorrhagic complications. P2Y12 receptor-mediated platelet inhibition was tested by using the VerifyNow assay device. The primary end points were postprocedural major and minor hemorrhagic complications. Receiver operator characteristic analysis was used to evaluate the percentage of platelet inhibition as a diagnostic tool for bleeding events. The association between hemorrhage and percentage of platelet inhibition was investigated by using logistic regression modeling.

RESULTS

Forty-seven patients were enrolled. The mean age was 56±12 years, and 28% were men. Ten patients (21.3%) developed hemorrhagic complications. Clopidogrel response was higher in patients with a major bleeding complication compared with those with minor or no bleeding (median, 94% versus 24% platelet inhibition; P=.0084). Of the 7 patients (14.9%) defined as hyper-responders with ≥72% platelet inhibition, 42.8% had a major bleeding complication.

CONCLUSIONS

Hyper-response to clopidogrel is associated with increased risk of hemorrhagic complications. Larger studies are urgently needed to validate a clinically useful threshold to define clopidogrel hyper-response and to examine the clinical effects of antiplatelet dosage adjustment.

Co-regulation of survival of motor neuron and Bcl-xL expression: implications for neuroprotection in spinal muscular atrophy

Spinal muscular atrophy (SMA), a fatal genetic motor disorder of infants, is caused by diminished full-length survival of motor neuron (SMN) protein levels. Normally involved in small nuclear ribonucleoprotein (snRNP) assembly and pre-mRNA splicing, recent studies suggest that SMN plays a critical role in regulating apoptosis. Interestingly, the anti-apoptotic Bcl-x isoform, Bcl-xL, is reduced in SMA. In a related finding, Sam68, an RNA-binding protein, was found to modulate splicing of SMN and Bcl-xL transcripts, promoting SMNΔ7 and pro-apoptotic Bcl-xS transcripts. Here we demonstrate that Bcl-xL expression increases SMN protein by ∼2-fold in SH-SY5Y cells. Conversely, SMN expression increases Bcl-xL protein levels by ∼6-fold in SH-SY5Y cells, and ∼2.5-fold in the brains of transgenic mice over-expressing SMN (PrP-SMN). Moreover, Sam68 protein levels were markedly reduced following SMN and Bcl-xL expression in SH-SY5Y cells, suggesting a feedback mechanism co-regulating levels of both proteins. We also found that exogenous SMN expression increased full-length SMN transcripts, possibly by promoting exon 7 inclusion. Finally, co-expression of SMN and Bcl-xL produced an additive anti-apoptotic effect following PI3-kinase inhibition in SH-SY5Y cells. Our findings implicate Bcl-xL as another potential target in SMA therapeutics, and indicate that therapeutic increases in SMN may arise from modest increases in total SMN.

Germline BRCA1 mutations increase prostate cancer risk

BACKGROUND

Prostate cancer (PrCa) is one of the most common cancers affecting men but its aetiology is poorly understood. Family history of PrCa, particularly at a young age, is a strong risk factor. There have been previous reports of increased PrCa risk in male BRCA1 mutation carriers in female breast cancer families, but there is a controversy as to whether this risk is substantiated. We sought to evaluate the role of germline BRCA1 mutations in PrCa predisposition by performing a candidate gene study in a large UK population sample set.

METHODS

We screened 913 cases aged 36–86 years for germline BRCA1 mutation, with the study enriched for cases with an early age of onset. We analysed the entire coding region of the BRCA1 gene using Sanger sequencing. Multiplex ligation-dependent probe amplification was also used to assess the frequency of large rearrangements in 460 cases.

RESULTS

We identified 4 deleterious mutations and 45 unclassified variants (UV). The frequency of deleterious BRCA1 mutation in this study is 0.45%; three of the mutation carriers were affected at age 65 years and one developed PrCa at 69 years. Using previously estimated population carrier frequencies, deleterious BRCA1 mutations confer a relative risk of PrCa of ~3.75-fold, (95% confidence interval 1.02–9.6) translating to a 8.6% cumulative risk by age 65.

CONCLUSION

This study shows evidence for an increased risk of PrCa in men who harbour germline mutations in BRCA1. This could have a significant impact on possible screening strategies and targeted treatments.

The use of midazolam and haloperidol in cancer patients at the end of life

INTRODUCTION

This study aimed to describe the patterns of sedative use among terminally ill cancer patients who were referred to a hospital-based specialist palliative care service for symptom management. It also aimed to examine whether sedative use among terminally ill cancer patients during the last two days of life had any impact on their survival.

METHODS

A retrospective review of case notes was carried out for patients with a diagnosis of terminal cancer, who died in a 95-bedded oncology ward between September 2006 and September 2007. Data was collected on patient characteristics, duration of palliative care, indications and doses of sedatives used at 48 hours and 24 hours before death.

RESULTS

A total of 238 patients died while receiving specialist palliative care, 132 of whom (55.5%) were female. At 48 hours and 24 hours before death, 22.6% and 24.8% of patients, respectively, were on sedatives like midazolam, haloperidol or both. The median dose of midazolam was 5 mg/day while the haloperidol dose at 48 hours and 24 hours before death was 3 mg/day and 4 mg/day, respectively. The indications for midazolam were anxiety, breathlessness and stiffness, while those for haloperidol were confusion agitation and nausea. Survival analysis showed no significant difference in survival between patients who were on sedatives and those who were not. The p-value for log-rank test was 0.78.

CONCLUSION

The results showed that the doses and overall frequency of sedative use in this patient population tended to be low and that usage of sedatives had no deleterious influence on survival.