14 research outputs found
Unbiased and automated identification of a circulating tumour cell definition that associates with overall survival
Circulating tumour cells (CTC) in patients with metastatic carcinomas are associated with poor survival and can be used to guide therapy. Classification of CTC however remains subjective, as they are morphologically heterogeneous. We acquired digital images, using the CellSearchâ„¢ system, from blood of 185 castration resistant prostate cancer (CRPC) patients and 68 healthy subjects to define CTC by computer algorithms. Patient survival data was used as the training parameter for the computer to define CTC. The computer-generated CTC definition was validated on a separate CRPC dataset comprising 100 patients. The optimal definition of the computer defined CTC (aCTC) was stricter as compared to the manual CellSearch CTC (mCTC) definition and as a consequence aCTC were less frequent. The computer-generated CTC definition resulted in hazard ratios (HRs) of 2.8 for baseline and 3.9 for follow-up samples, which is comparable to the mCTC definition (baseline HR 2.9, follow-up HR 4.5). Validation resulted in HRs at baseline/follow-up of 3.9/5.4 for computer and 4.8/5.8 for manual definitions. In conclusion, we have defined and validated CTC by clinical outcome using a perfectly reproducing automated algorithm
Visuospatial Processing Deficits Linked to Posterior Brain Regions in Premanifest and Early Stage Huntington's Disease.
OBJECTIVES: Visuospatial processing deficits have been reported in Huntington's disease (HD). To date, no study has examined associations between visuospatial cognition and posterior brain findings in HD. METHODS: We compared 119 premanifest (55> and 64<10.8 years to expected disease onset) and 104 early symptomatic (59 stage-1 and 45 stage-2) gene carriers, with 110 controls on visual search and mental rotation performance at baseline and 12 months. In the disease groups, we also examined associations between task performance and disease severity, functional capacity and structural brain measures. RESULTS: Cross-sectionally, there were strong differences between all disease groups and controls on visual search, and between diagnosed groups and controls on mental rotation accuracy. Only the premanifest participants close to onset took longer than controls to respond correctly to mental rotation. Visual search negatively correlated with disease burden and motor symptoms in diagnosed individuals, and positively correlated with functional capacity. Mental rotation ("same") was negatively correlated with motor symptoms in stage-2 individuals, and positively correlated with functional capacity. Visual search and mental rotation were associated with parieto-occipital (pre-/cuneus, calcarine, lingual) and temporal (posterior fusiform) volume and cortical thickness. Longitudinally, visual search deteriorated over 12 months in stage-2 individuals, with no evidence of declines in mental rotation. CONCLUSIONS: Our findings provide evidence linking early visuospatial deficits to functioning and posterior cortical dysfunction in HD. The findings are important since large research efforts have focused on fronto-striatal mediated cognitive changes, with little attention given to aspects of cognition outside of these areas. (JINS, 2016, 22, 595-608)
Mendelian Randomisation study of the influence of eGFR on coronary heart disease.
Impaired kidney function, as measured by reduced estimated glomerular filtration rate (eGFR), has been associated with increased risk of coronary heart disease (CHD) in observational studies, but it is unclear whether this association is causal or the result of confounding or reverse causation. In this study we applied Mendelian randomisation analysis using 17 genetic variants previously associated with eGFR to investigate the causal role of kidney function on CHD. We used 13,145 participants from the UCL-LSHTM-Edinburgh-Bristol (UCLEB) Consortium and 194,427 participants from the Coronary ARtery DIsease Genome-wide Replication and Meta-analysis plus Coronary Artery Disease (CARDIoGRAMplusC4D) consortium. We observed significant association of an unweighted gene score with CHD risk (odds ratio = 0.983 per additional eGFR-increasing allele, 95% CI = 0.970-0.996, p = 0.008). However, using weights calculated from UCLEB, the gene score was not associated with disease risk (p = 0.11). These conflicting results could be explained by a single SNP, rs653178, which was not associated with eGFR in the UCLEB sample, but has known pleiotropic effects that prevent us from drawing a causal conclusion. The observational association between low eGFR and increased CHD risk was not explained by potential confounders, and there was no evidence of reverse causation, therefore leaving the remaining unexplained association as an open question
Improved survival in a cohort of trial participants with metastatic castration-resistant prostate cancer demonstrates the need for updated prognostic nomograms.
BACKGROUND: Median overall survival (OS) in men with metastatic castration-resistant prostate cancer (CRPC) was 13-16 mo in the predocetaxel era. Prognostic nomograms for survival estimation in CRPC were constructed prior to the introduction of docetaxel and other novel treatments. OBJECTIVE: To examine whether prognostic models still accurately reflect survival in a large cohort of trial participants. DESIGN, SETTING, AND PARTICIPANTS: Survival analysis of 442 men with CRPC sequentially treated in clinical trials at our institution from June 2003 to December 2011. OUTCOME MEASURES AND STATISTICAL ANALYSIS: Predicted survival by Halabi and Smaletz nomograms was compared to observed survival. Cox model multivariate analysis (MVA) used variables at referral, including performance status (PS); levels of prostate-specific antigen (PSA), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), haemoglobin (Hb), and albumin; presence of visceral disease, and metastatic disease at diagnosis. RESULTS AND LIMITATIONS: From point of referral, chemotherapy-naïve patients had a median OS of 30.6 mo (95% confidence interval [CI], 27.6-36.5 mo). In contrast, predicted survival using the Halabi and Smaletz models was 21 and 18 mo, respectively. In these patients, poor PS, lower Hb level, and increasing LDH level were the strongest predictors in the MVA. In patients referred after chemotherapy, survival from referral was 17.5 mo (95% CI, 16.0-19.5 mo) and increasing LDH level and presence of visceral metastases were the strongest predictors of survival. Median OS from diagnosis of CRPC was 40.7 mo in the overall cohort (95% CI, 36.8-44.0 mo). Clinical trial participation was safe, with low mortality rate. This cohort of men participated in phase 1, 2 and 3 trials and expanded access programs; their data may not reflect survival in all CRPC patients. CONCLUSIONS: Due to the impact of highly effective novel therapies on survival, prognostic nomograms in current use require revalidation regarding their ability to predict survival in CRPC
Factors Associated with Greater Adherence to and Satisfaction with Transdermal Rivastigmine in Patients with Alzheimer's Disease and Their Caregivers
<b><i>Background/Aims:</i></b> Adherence to cholinesterase inhibitors is important in order to maximise treatment efficacy. This study aimed to investigate patient and caregiver factors associated with adherence to and satisfaction with transdermal rivastigmine treatment. <b><i>Methods:</i></b> Sociodemographic, clinical and psychosocial data were collected from 127 patients and their caregivers during the first follow-up visit after prescription. At the second follow-up, data were collected on 110 of the dyads. Adherence to and satisfaction with the treatment were assessed using the Medication Adherence Report Scale and an adapted version of the Alzheimer's Disease Caregiver Preference Questionnaire. <b><i>Results:</i></b> 66.2% of the caregivers reported being adherent to, and 77.0% were satisfied with, the patch at the second follow-up. Factors predicting higher adherence at the second follow-up were caregivers' greater frequency of contact with patients, greater satisfaction with the information received about the patch, better tolerability of the patch and living at home with their caregivers. Greater concerns of the caregivers about the patch and the patients' belief in ‘other' causes of their Alzheimer's disease predicted a lower adherence at the second follow-up. <b><i>Conclusions:</i></b> Assessing and addressing caregivers' concerns about transdermal rivastigmine, improving doctor-patient/caregiver communication to increase caregiver satisfaction with information about the patch as well as providing education and support around patients' beliefs and tolerability of the patch could improve adherence to transdermal rivastigmine.</jats:p
Frequency distributions of mCTC and aCTC from patients (N = 185) and control samples (N = 68).
<p>The top row shows the mCTC frequency distribution (panel A). The next rows show the number of aCTC for the optimal aCTC definition (panel B), the classifier without the CD45 exclusion criterion (panel C), without the DAPI criterion (panel D), and of TMP objects that are EpCAM+CK+CD45- and <4 µm in diameter (panel E). The percentage of patients with 0 objects is shown numerically on the left. On the right the HRs derived by dichotomizing on the median number of objects in patients are shown, together with the 25, 50, and 75 percentiles. The percentiles are also indicated in the plot.</p
Kaplan-Meier plots of the classifier (grey lines) and the manual CellSearch (black lines) definition.
<p>The training set is shown in panel A (baseline, N = 185) and panel B (follow-up, N = 185). Kaplan-Meier plots for the validation set are shown in panel C (baseline, N = 93) and panel D (follow-up, N = 96). Censoring is indicated by vertical marks on the Kaplan-Meier plot.</p
Disagreement concerning atopic dermatitis subtypes between an English prospective cohort (ALSPAC) and linked electronic health records
BackgroundSubtypes of atopic dermatitis (AD) have been derived from the Avon Longitudinal Study of Parents and Children (ALSPAC) based on presence and severity of symptoms reported in questionnaires (Severe–Frequent, Moderate–Frequent, Moderate–Declining, Mild–Intermittent, Unaffected/Rare). Good agreement between ALSPAC and linked electronic health records (EHRs) would increase trust in the clinical validity of these subtypes and allow inferring subtypes from EHRs alone, which would enable their study in large primary care databases.Objectives1. Explore if presence and number of AD records in EHRs agrees with AD symptom and severity reports from ALSPAC; 2. Explore if EHRs agree with ALSPAC-derived AD subtypes; 3. Construct models to classify ALSPAC-derived AD subtype using EHRs.MethodsWe used data from the ALSPAC prospective cohort study from 11 timepoints until age 14 years (1991–2008), linked to local general practice EHRs. We assessed how far ALSPAC questionnaire responses and derived subtypes agreed with AD as established in EHRs using different AD definitions (e.g., diagnosis and/or prescription) and other AD-related records. We classified AD subtypes using EHRs, fitting multinomial logistic regression models tuning hyperparameters and evaluating performance in the testing set (ROC AUC, accuracy, sensitivity, and specificity).Results8,828 individuals out of a total 13,898 had both been assigned an AD subtype and had linked EHRs. The number of AD-related codes in EHRs generally increased with severity of AD subtype, however not all with the Severe-Frequent subtypes had AD in EHRs, and many with the Unaffected/Rare subtype did have AD in EHRs. When predicting ALSPAC AD subtype using EHRs, the best tuned model had ROC AUC of 0.65, sensitivity of 0.29 and specificity of 0.83 (both macro averaged); when different sets of predictors were used, individuals with missing EHR coverage excluded, and subtypes combined, sensitivity was not considerably improved.ConclusionsALSPAC and EHRs disagreed not just on AD subtypes, but also on whether children had AD or not. Researchers should be aware that individuals considered as having AD in one source may not be considered as having AD in another
Schematic overview of the aCTC classifier development process.
<p>A: importing of images; B: object segmentation; C: feature measurements; D: classification of aCTC.</p
aCTC and mCTC cut-off values with HRs, median OS, for baseline (panel A) and first follow-up samples (panel B) for the validation set enrolled in Phase I/II trials of abiraterone acetate at Royal Marsden Hospital.
<p>*Overall Survival.</p>†<p>Hazard Ratio.</p