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"Sykes, Jenna"
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Spatial genomic heterogeneity within localized, multifocal prostate cancer
2015
Paul Boutros, Robert Bristow and colleagues report a molecular analysis of the spatial heterogeneity of clinically localized, multifocal prostate cancer. They find that multifocal tumors are highly heterogeneous, and they identify a novel recurrent amplification of
MYCL1
.
Herein we provide a detailed molecular analysis of the spatial heterogeneity of clinically localized, multifocal prostate cancer to delineate new oncogenes or tumor suppressors. We initially determined the copy number aberration (CNA) profiles of 74 patients with index tumors of Gleason score 7. Of these, 5 patients were subjected to whole-genome sequencing using DNA quantities achievable in diagnostic biopsies, with detailed spatial sampling of 23 distinct tumor regions to assess intraprostatic heterogeneity in focal genomics. Multifocal tumors are highly heterogeneous for single-nucleotide variants (SNVs), CNAs and genomic rearrangements. We identified and validated a new recurrent amplification of
MYCL
, which is associated with
TP53
deletion and unique profiles of DNA damage and transcriptional dysregulation. Moreover, we demonstrate divergent tumor evolution in multifocal cancer and, in some cases, tumors of independent clonal origin. These data represent the first systematic relation of intraprostatic genomic heterogeneity to predicted clinical outcome and inform the development of novel biomarkers that reflect individual prognosis.
Journal Article
Tumour genomic and microenvironmental heterogeneity for integrated prediction of 5-year biochemical recurrence of prostate cancer: a retrospective cohort study
by
Ramnarine, Varune R
,
Mak, Denise Y F
,
Chu, Kenneth C
in
Antigens
,
Biomarkers, Tumor - genetics
,
Biopsy
2014
Clinical prognostic groupings for localised prostate cancers are imprecise, with 30–50% of patients recurring after image-guided radiotherapy or radical prostatectomy. We aimed to test combined genomic and microenvironmental indices in prostate cancer to improve risk stratification and complement clinical prognostic factors.
We used DNA-based indices alone or in combination with intra-prostatic hypoxia measurements to develop four prognostic indices in 126 low-risk to intermediate-risk patients (Toronto cohort) who will receive image-guided radiotherapy. We validated these indices in two independent cohorts of 154 (Memorial Sloan Kettering Cancer Center cohort [MSKCC] cohort) and 117 (Cambridge cohort) radical prostatectomy specimens from low-risk to high-risk patients. We applied unsupervised and supervised machine learning techniques to the copy-number profiles of 126 pre-image-guided radiotherapy diagnostic biopsies to develop prognostic signatures. Our primary endpoint was the development of a set of prognostic measures capable of stratifying patients for risk of biochemical relapse 5 years after primary treatment.
Biochemical relapse was associated with indices of tumour hypoxia, genomic instability, and genomic subtypes based on multivariate analyses. We identified four genomic subtypes for prostate cancer, which had different 5-year biochemical relapse-free survival. Genomic instability is prognostic for relapse in both image-guided radiotherapy (multivariate analysis hazard ratio [HR] 4·5 [95% CI 2·1–9·8]; p=0·00013; area under the receiver operator curve [AUC] 0·70 [95% CI 0·65–0·76]) and radical prostatectomy (4·0 [1·6–9·7]; p=0·0024; AUC 0·57 [0·52–0·61]) patients with prostate cancer, and its effect is magnified by intratumoral hypoxia (3·8 [1·2–12]; p=0·019; AUC 0·67 [0·61–0·73]). A novel 100-loci DNA signature accurately classified treatment outcome in the MSKCC low-risk to intermediate-risk cohort (multivariate analysis HR 6·1 [95% CI 2·0–19]; p=0·0015; AUC 0·74 [95% CI 0·65–0·83]). In the independent MSKCC and Cambridge cohorts, this signature identified low-risk to high-risk patients who were most likely to fail treatment within 18 months (combined cohorts multivariate analysis HR 2·9 [95% CI 1·4–6·0]; p=0·0039; AUC 0·68 [95% CI 0·63–0·73]), and was better at predicting biochemical relapse than 23 previously published RNA signatures.
This is the first study of cancer outcome to integrate DNA-based and microenvironment-based failure indices to predict patient outcome. Patients exhibiting these aggressive features after biopsy should be entered into treatment intensification trials.
Movember Foundation, Prostate Cancer Canada, Ontario Institute for Cancer Research, Canadian Institute for Health Research, NIHR Cambridge Biomedical Research Centre, The University of Cambridge, Cancer Research UK, Cambridge Cancer Charity, Prostate Cancer UK, Hutchison Whampoa Limited, Terry Fox Research Institute, Princess Margaret Cancer Centre Foundation, PMH-Radiation Medicine Program Academic Enrichment Fund, Motorcycle Ride for Dad (Durham), Canadian Cancer Society.
Journal Article
International variation in ethics and contract approval processes for a low-risk observational study of mechanical ventilation discontinuation practices
by
Cook, Deborah J.
,
Rizvi, Leena
,
Griffin, Katherine
in
Children & youth
,
Clinical trials
,
Consortia
2023
To describe international variation in ethics and contract processes, identify predictors of approval times, and reasons for nonparticipation in an international observational study of ventilation discontinuation practices.
A nested cross-sectional survey of research personnel at 111 participating sites (representing 142 intensive care units [ICUs]) from six geographic regions (Canada, India, the United Kingdom, Europe, Australia/New Zealand, and the United States).
We analyzed responses from 80 sites (72.1% response rate). A single local or central approval was required at 34/80 (42.5%) and 23/80 (28.75%), respectively. Of those requiring central ethics approval, 20/23 (87.0%) sites required an additional approval. Sites with central vs. other ethics approval processes had significantly longer times to ethics approval (176 vs. 42 days; P < 0.0001). The median time to contract execution was 140 days (range: 11–1,215) with sites in India and the United States having the shortest and longest times to contract execution, respectively. We did not identify independent predictors of approval times. Of 190 sites that initially agreed to participate, 78 (41%) sites (89 ICUs) were ultimately unable to participate.
International ethics and contract approval times were lengthy and highly variable. Central ethics review processes significantly increased approval times.
•Few large-scale studies have evaluated variation in approval processes in observational studies and across geographic regions.•Large and important regional variation exists in ethics and contract approval processes for low-risk observational research.•Central ethics (vs. other) approval processes significantly increased approval times as central approval did not supplant the need for additional approvals at 87% of participating sites.•Forty percent of sites who initially agreed to participate were ultimately unable to participate primarily due to loss to follow-up and insufficient personnel.•Our findings highlight the need for streamlined ethics and contract review processes for low-risk, multicenter, observational studies.
Journal Article
MATE2 Expression Is Associated with Cancer Cell Response to Metformin
by
Bristow, Robert G.
,
McKee, Trevor
,
Sykes, Jenna
in
Animals
,
Antidiabetics
,
Antineoplastic Agents - pharmacology
2016
There is great interest in repurposing the commonly prescribed anti-diabetic drug metformin for cancer therapy. Intracellular uptake and retention of metformin is affected by the expression of organic cation transporters (OCT) 1-3 and by multidrug and toxic compound extrusion (MATE) 1-2. Inside cells, metformin inhibits mitochondrial function, which leads to reduced oxygen consumption and inhibition of proliferation. Reduced oxygen consumption can lead to improved tumor oxygenation and radiation response.
Here we sought to determine if there is an association between the effects of metformin on inhibiting oxygen consumption, proliferation and expression of OCTs and MATEs in a panel of 19 cancer cell lines.
There was relatively large variability in the anti-proliferative response of different cell lines to metformin, with a subset of cell lines being very resistant. In contrast, all cell lines demonstrated sensitivity to the inhibition of oxygen consumption by metformin, with relatively small variation. The expression of OCT1 correlated with expression of both OCT2 and OCT3. OCT1 and OCT2 were relatively uniformly expressed, whereas expression of OCT3, MATE1 and MATE2 showed substantial variation across lines. There were statistically significant associations between resistance to inhibition of proliferation and MATE2 expression, as well as between sensitivity to inhibition of oxygen consumption and OCT3 expression. One cell line (LNCaP) with high OCT3 and low MATE2 expression in concert, had substantially higher intracellular metformin concentration than other cell lines, and was exquisitely sensitive to both anti-proliferative and anti-respiratory effects. In all other cell lines, the concentration of metformin required to inhibit oxygen consumption acutely in vitro was substantially higher than that achieved in the plasma of diabetic patients. However, administering anti-diabetic doses of metformin to tumor-bearing mice resulted in intratumoral accumulation of metformin and reduced hypoxic tumor fractions.
All cancer cells are susceptible to inhibition of oxygen consumption by metformin, which results in reduced hypoxic tumor fractions beneficial for the response to radiotherapy. High MATE2 expression may result in resistance to the anti-proliferative effect of metformin and should be considered as a negative predictive biomarker in clinical trials.
Journal Article
Protease nexin 1 inhibits hedgehog signaling in prostate adenocarcinoma
by
Mallof, Chad
,
Beech, John
,
Hamdy, Freddie
in
Adenocarcinoma
,
Adenocarcinoma - genetics
,
Adenocarcinoma - metabolism
2012
Prostate adenocarcinoma (CaP) patients are classified into low-, intermediate-, and high-risk groups that reflect relative survival categories. While there are accepted treatment regimens for low- and high-risk patients, intermediate-risk patients pose a clinical dilemma, as treatment outcomes are highly variable for these individuals. A better understanding of the factors that regulate the progression of CaP is required to delineate risk. For example, aberrant activation of the Hedgehog (Hh) pathway is implicated in CaP progression. Here, we identify the serine protease inhibitor protease nexin 1 (PN1) as a negative regulator of Hh signaling in prostate. Using human CaP cell lines and a mouse xenograft model of CaP, we demonstrate that PN1 regulates Hh signaling by decreasing protein levels of the Hh ligand Sonic (SHH) and its downstream effectors. Furthermore, we show that SHH expression enhanced tumor growth while overexpression of PN1 inhibited tumor growth and angiogenesis in mice. Finally, using comparative genome hybridization, we found that genetic alterations in Hh pathway genes correlated with worse clinical outcomes in intermediate-risk CaP patients, indicating the importance of this pathway in CaP.
Journal Article
Retrospective assessment of patterns of recurrence relative to radiotherapy volumes for adjuvant conformal chemoradiotherapy in gastric cancer
2016
Background
Since the Intergroup 0116 study was published in 2000, adjuvant postoperative chemoradiotherapy using CT-planned and 3D conformal/intensity-modulated radiotherapy has been offered routinely to fit patients with resected gastric cancer at Princess Margaret Hospital .The objective of this study was to analyze patterns of disease recurrence with respect to the radiotherapy volumes.
Methods
For the date and site (local, locoregional, or distant) of the first recurrence, medical records were reviewed for all patients treated at Princess Margaret Hospital with adjuvant chemoradiotherapy for resected gastric adenocarcinoma (January 1, 2000 to November 30, 2009). Patients whose recurrences were limited to local and/or regional sites were selected for further analysis. Available diagnostic imaging of the recurrence site was registered to the original planning radiotherapy dataset for contouring. If necessary to respect changes in anatomy, the contour was translocated on the basis of anatomic descriptors. The center of mass for each recurrence was identified as a point and its location was categorized according to the isodose encompassing it; in field (90 % or more), marginal (50–89 %), or out of field (less than 50 %).
Results
Of all 197 patients, 14 (7 %) had isolated locoregional failure, constituting 20 % of all 71 patients with a recurrence. Successful fusions were feasible in five cases. Of these recurrences, four were in field and one was marginal. In a further four cases, visual inspection was used, showing one in-field recurrence, one marginal recurrence, and two out-of-field recurrences. In five patients, either a useable original dataset or diagnostic imaging of the recurrence was not available.
Conclusions
The rates of isolated local/locoregional tumor recurrence in this study were low. Of the small number of recurrences available for analysis, most (five of nine) were in field. Further studies involving a larger cohort of patients might allow a more meaningful analysis of trends in the recurrence site with evolving radiotherapy techniques.
Journal Article
Beyond borders: cystic fibrosis survival between Australia, Canada, France and New Zealand
by
Ma, Xiayi
,
Lemonnier, Lydie
,
Stephenson, Anne L
in
Accounting
,
Aged
,
Australia - epidemiology
2023
BackgroundLife expectancy for people with cystic fibrosis (CF) varies considerably both within and between countries. The objective of this study was to compare survival among countries with single-payer healthcare systems while accounting for markers of disease severity.MethodsThis cohort study used data from established national CF registries in Australia, Canada, France and New Zealand from 2015 to 2019. Median age of survival for each of the four countries was estimated using the Kaplan-Meier method. A Cox proportional hazards model was used to compare risk of death between Canada, France and Australia after adjusting for prognostic factors. Due to low number of deaths, New Zealand was not included in final adjusted models.ResultsBetween 2015 and 2019, a total of 14 842 people (3537 Australia, 4434 Canada, 6411 France and 460 New Zealand) were included. The median age of survival was highest in France 65.9 years (95% CI: 59.8 to 76.0) versus 53.3 years (95% CI: 48.9 to 59.8) for Australia, 55.4 years (95% CI: 51.3 to 59.2) for Canada and 54.8 years (95% CI: 40.7 to not available) for New Zealand. After adjusting for individual-level factors, the risk of death was significantly higher in Canada (HR 1.85, 95% CI: 1.48 to 2.32; p<0.001) and Australia (HR 2.08, 95% CI: 1.64 to 2.64; p<0.001) versus France.InterpretationWe observed significantly higher survival in France compared with countries with single-payer healthcare systems. The median age of survival in France exceeded 60 years of age despite having the highest proportion of underweight patients which may be due to differences in availability of transplant.
Journal Article
Comparison of Nutrition and Lung Function Outcomes in Patients with Cystic Fibrosis Living in Canada and the United States
2018
Abstract
Rationale
A 10-year gap in the median age of survival for patients with cystic fibrosis (CF) was reported between patients living in Canada compared with patients living in the United States.
Objectives
Because both malnutrition and poor lung function are associated with an increased risk of mortality in CF, we investigated the temporal and longitudinal trends in lung function and nutrition between Canada and the United States.
Methods
This cohort study used Canadian CF Registry and U.S. CF Foundation Patient Registry data from 1990 to 2013. A unified dataset was created to harmonize the variables collected within the two registries for the purpose of comparing outcomes between the two countries.
Measurements and Main Results
We conducted three analyses: survival differences by birth cohort; population trends for FEV1 and body mass index (BMI) over time; and individual patient FEV1 and BMI trajectories. The study included a total of 37,772 patients in the United States and 5,149 patients in Canada. Patients with CF experienced significant improvements in nutritional status and lung function in both Canada and the United States during the study. In addition, the survival gap between the two countries is narrowing within younger birth cohorts. The improvements for the patients within the United States were most prominent in the BMI trajectories, where patients born after 1990 in the United States have higher BMI that has persisted over time.
Conclusions
The reasons for the observed improvements, and catch-up in the United States, are likely multifactorial and include the introduction of high-fat, high-calorie diets; introduction of newborn screening; and/or improved access to care for CF children in the United States.
Journal Article
Clinical Characteristics and Predictors of Reduced Survival for Adult-diagnosed Cystic Fibrosis. Analysis of the Canadian CF Registry
2018
Individuals diagnosed with cystic fibrosis (CF) as adults represent a growing subpopulation of CF cases, but there are limited studies describing their characteristics and prognosis.
The objectives of this study were to describe the clinical characteristics of individuals with adult-diagnosed CF, estimate survival rates in this population, and identify clinical predictors of reduced survival at baseline.
The Canadian CF Patient Registry was used to identify patients with CF who were ≥18 years of age at diagnosis and received a diagnosis between 1990 and 2014. Clinical characteristics were described and the Kaplan-Meier method was used to estimate lung-transplant-free survival. Multivariable Cox regression analysis and adjusted survival curves were employed to identify important predictors of reduced survival at the time of diagnosis (i.e., baseline) and to produce adjusted effects.
A total of 362 adults were diagnosed with CF during the study period. The median follow-up time was 7.7 years and 48 individuals experienced an event (15 transplants, 33 deaths without transplant). The median age at diagnosis was 34.3 years, with the majority of individuals presenting with pulmonary and/or gastrointestinal symptoms (71%). Lung-transplant-free survival was 88% at 10 years and 86% at 15 years. Age at diagnosis (hazard ratio [HR], 1.24 per 5-year increase, 95% confidence interval [CI], 1.09-1.43), diabetes (HR, 4.19; 95% CI, 1.35-13.01), and lung function (HR, 1.35 per 5% decrease in forced expiratory volume in 1 second % predicted; 95% CI, 1.24-1.48) at baseline were important predictors of reduced survival.
CF care providers can use this information to inform individuals who received a diagnosis of CF as adults about their prognosis and to guide the necessity of treatments, specifically with regard to those who are at high risk for a worse prognosis.
Journal Article
A standardized approach to estimating survival statistics for population-based cystic fibrosis registry cohorts
2016
Our objective was to quantify the effect of different statistical techniques, inclusion/exclusion criteria, and missing data on the predicted median survival age.
Using the Canadian cystic fibrosis registry (CCFR), the median age of survival was calculated using both the Cox proportional hazards (PH) and the life-table methods. Through simulations, we examined how the median age of survival would change when: (1) patients were excluded, (2) death dates were inaccurate, (3) patients were lost to follow-up, (4) entire years with no clinic visits were excluded even if the patient had a visit in subsequent years, and (5) censoring patients at their date of transplant. Simulations were run assuming 5–35% of data were affected by each scenario.
Over the period 2009–2013, there were 4,666 individuals in the CCFR with 240 deaths. The observed median age of survival calculated by the Cox PH method was 50.9 [95% confidence interval (CI): 47.4, 54.3] and 50.5 from the life-table method (95% CI: 47.5, 53.5). Censoring patients at their transplant date overestimated the median age of survival by 7.2 years (58.1; 95% CI: 53.3, 64.7). Simulations determined that by missing just 15% of deaths, the median age of survival can be overestimated by 3.5 years (54.4; 95% CI: 54.2, 56.1), and having 25% of patients lost to follow-up can underestimate the median age of survival by 3.3 years (47.6; 95% CI: 46.8, 47.7).
We present several recommendations to assist national cystic fibrosis registries in calculating and reporting the median age of survival in a standardized fashion. It is imperative to state the statistical method used as well as the proportion lost to follow-up and the treatment of missing data and transplanted patients. Registries must be diligent in their data collection as incomplete data can lead to overestimation and underestimation of survival.
Journal Article