Effect of high-flow nasal therapy on patient-centred outcomes in patients at high risk of postoperative pulmonary complications after cardiac surgery: a statistical analysis plan for NOTACS, a multicentre adaptive randomised controlled trial.

BACKGROUND: The NOTACS trial will assess the efficacy, safety and cost-effectiveness of high-flow nasal therapy (HFNT) compared to standard oxygen therapy (SOT) on the outcomes of patients after cardiac surgery. METHODS/DESIGN: NOTACS is an adaptive, international, multicentre, parallel-group, randomised controlled trial, with a pre-planned interim sample size re-estimation (SSR). A minimum of 850 patients will be randomised 1:1 to receive either HFNT or SOT. The primary outcome is days alive and at home in the first 90 days after the planned surgery (DAH90), with a number of secondary analyses and cost-effectiveness analyses also planned. The interim SSR will take place after a minimum of 300 patients have been followed up for 90 days and will allow for the sample size to increase up to a maximum of 1152 patients. RESULTS: This manuscript provides detailed descriptions of the design of the NOTACS trial, and the analyses to be undertaken at the interim and final analyses. The main purpose of the interim analysis is to assess safety and to perform a sample size re-estimation. The main purpose of the final analysis is to examine the safety, efficacy and cost-effectiveness of HFNT compared to SOT on the outcomes of patients after cardiac surgery. DISCUSSION: This manuscript outlines the key features of the NOTACS statistical analysis plan and was submitted to the journal before the interim analysis in order to preserve scientific integrity under an adaptive design framework. The NOTACS SAP closely follows published guidelines for the content of SAPs in clinical trials. TRIAL REGISTRATION: ISRCTN14092678 . Registered on 13 May 2020.

Lactate during ex-situ heart perfusion does not predict the requirement for mechanical circulatory support following donation after circulatory death (DCD) heart transplants.

BACKGROUND: Ex-situ heart perfusion (ESHP) is commonly used for the reanimation and preservation of hearts following donation after circulatory determined death (DCD). The only commercially available existing ESHP device promotes perfusate lactate levels for assessment of heart viability. The reliability of this marker is yet to be confirmed for DCD heart transplantation. METHODS: This is a single center, retrospective study examining DCD heart transplants from March 1, 2015 to June 30, 2020. Recipients were divided into 2 groups dependent upon their requirement for or absence of mechanical circulatory support post-transplant. Lactate profiles obtained during ESHP were analyzed. Hearts were procured using the direct procurement and perfusion (DPP) method. RESULTS: Fifty-one DCD heart transplant recipients were studied, of which 20 (39%) were dependent on mechanical circulatory support (MCS) following transplantation, (2% Ventricular Assist Device (VAD), 16% Extra Corporeal Membrane Oxygenation (ECMO) and 21% Intra-aortic balloon pumps (IABP). There was no difference in arterial lactate profiles on ESHP at any time point for those dependent upon MCS support (MCS) and those that were not (no MCS) post-transplant. After 3 hours of ESHP, the arterial lactate was >5mmol/L in 80% upon MCS vs 62% no MCS, p = .30. There was also no difference in ESHP rising arterial lactate concentrations, (15% MCS vs 13% non MCS, p = 1.00). CONCLUSION: For DCD hearts transplants retrieved using the DPP technique, lactate profiles do not seem to be a reliable predictor of mechanical circulatory support requirement post-transplant.

Analysis of heterogeneity in T2-weighted MR images can differentiate pseudoprogression from progression in glioblastoma.

PURPOSE: To develop an image analysis technique that distinguishes pseudoprogression from true progression by analyzing tumour heterogeneity in T2-weighted images using topological descriptors of image heterogeneity called Minkowski functionals (MFs). METHODS: Using a retrospective patient cohort (n = 50), and blinded to treatment response outcome, unsupervised feature estimation was performed to investigate MFs for the presence of outliers, potential confounders, and sensitivity to treatment response. The progression and pseudoprogression groups were then unblinded and supervised feature selection was performed using MFs, size and signal intensity features. A support vector machine model was obtained and evaluated using a prospective test cohort. RESULTS: The model gave a classification accuracy, using a combination of MFs and size features, of more than 85% in both retrospective and prospective datasets. A different feature selection method (Random Forest) and classifier (Lasso) gave the same results. Although not apparent to the reporting radiologist, the T2-weighted hyperintensity phenotype of those patients with progression was heterogeneous, large and frond-like when compared to those with pseudoprogression. CONCLUSION: Analysis of heterogeneity, in T2-weighted MR images, which are acquired routinely in the clinic, has the potential to detect an earlier treatment response allowing an early change in treatment strategy. Prospective validation of this technique in larger datasets is required.

Whole blood mRNA in prostate cancer reveals a four-gene androgen regulated panel.

Due to increased sensitivity, the expression of circulating nucleotides is rapidly gaining popularity in cancer diagnosis. Whole blood mRNA has been used in studies on a number of cancers, most notably two separate studies that used whole blood mRNA to define non-overlapping signatures of prostate cancer that has become castration independent. Prostate cancer is known to rely on androgens for initial growth, and there is increasing evidence on the importance of the androgen axis in advanced disease. Using whole blood mRNA samples from patients with prostate cancer, we have identified the four-gene panel of FAM129A, MME, KRT7 and SOD2 in circulating mRNA that are differentially expressed in a discovery cohort of metastatic samples. Validation of these genes at the mRNA and protein level was undertaken in additional cohorts defined by risk of relapse following surgery and hormone status. All the four genes were downregulated at the mRNA level in the circulation and in primary tissue, but this was not always reflected in tissue protein expression. MME demonstrated significant differences in the hormone cohorts, whereas FAM129A is downregulated at the mRNA level but is raised at the protein level in tumours. Using published ChIP-seq data, we have demonstrated that this may be due to AR binding at the FAM129A and MME loci in multiple cell lines. These data suggest that whole blood mRNA of androgen-regulated genes has the potential to be used for diagnosis and monitoring of prostate cancer.

Boosting Wnt activity during colorectal cancer progression through selective hypermethylation of Wnt signaling antagonists.

BACKGROUND: There is emerging evidence that Wnt pathway activity may increase during the progression from colorectal adenoma to carcinoma and that this increase is potentially an important step towards the invasive stage. Here, we investigated whether epigenetic silencing of Wnt antagonists is the biological driver for this increased Wnt activity in human tissues and how these methylation changes correlate with MSI (Microsatelite Instability) and CIMP (CpG Island Methylator Phenotype) statuses as well as known mutations in genes driving colorectal neoplasia. METHODS: We conducted a systematic analysis by pyrosequencing, to determine the promoter methylation of CpG islands associated with 17 Wnt signaling component genes. Methylation levels were correlated with MSI and CIMP statuses and known mutations within the APC, BRAF and KRAS genes in 264 matched samples representing the progression from normal to pre-invasive adenoma to colorectal carcinoma. RESULTS: We discovered widespread hypermethylation of the Wnt antagonists SFRP1, SFRP2, SFRP5, DKK2, WIF1 and SOX17 in the transition from normal to adenoma with only the Wnt antagonists SFRP1, SFRP2, DKK2 and WIF1 showing further significant increase in methylation from adenoma to carcinoma. We show this to be accompanied by loss of expression of these Wnt antagonists, and by an increase in nuclear Wnt pathway activity. Mixed effects models revealed that mutations in APC, BRAF and KRAS occur at the transition from normal to adenoma stages whilst the hypermethylation of the Wnt antagonists continued to accumulate during the transitions from adenoma to carcinoma stages. CONCLUSION: Our study provides strong evidence for a correlation between progressive hypermethylation and silencing of several Wnt antagonists with stepping-up in Wnt pathway activity beyond the APC loss associated tumour-initiating Wnt signalling levels.

Detailed analysis of operating time learning curves in robotic prostatectomy by a novice surgeon.

OBJECTIVES: Structured mentor-led training programmes permit the safe introduction of novice trainees to robotic-assisted laparoscopic prostatectomy (RALP). We outline the first description of parallel learning curves for individual surgical steps and quantify the relative difficulty of each step to propose an order of training in our structured mentoring programme. PATIENTS AND METHODS: A prospective ethically approved database was used to evaluate the operating times of each individual surgical step, in the first 150 RALP cases performed independently by a robotic-naive laparoscopic surgeon. Linear regression analysis was used to quantify the effect of surgeon experience on the operating time for each individual surgical step. RESULTS: Univariate linear regression analysis revealed significant reductions in operating time over the first 150 cases for all of the RALP steps, with the exception of the Rocco stitch. Multivariate linear regression analysis compensated for confounding variables and led to the identification of five surgical steps in which the operating time of each was significantly influenced by experience of the procedure. The most substantial improvement in operating time was seen in the bladder take down step. After taking into account the multivariate regression model, standardized univariate coefficients allowed an order of training to be identified for future RALP novices, of increasing complexity rather than order of surgery, beginning with the bladder take down step and ending with the vesico-urethral anastomosis. CONCLUSIONS: We can begin the training of new robotic-naive surgeons at simpler surgical steps, in which the greatest gains in expediency are made. We anticipate that identifying the more challenging surgical steps from this study and targeting training towards them may expedite our future trainees' proficiency at RALP.