David Zhen

Dr. David Zhen

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 November 2014 in Genetics in Medicine
Verified
Journal Article
Open access
PDF file
DZDavid Zhen
David Zhen
KRKari G. Rabe
Kari G. Rabe
SGSteven Gallinger
Steven Gallinger
SSSapna Syngal
Sapna Syngal
ASAnn G. Schwartz
Ann G. Schwartz
GPGloria M. Petersen
Gloria M. Petersen
Purpose: Familial pancreatic cancer kindreds contain at least two affected first-degree relatives. Comprehensive data are needed to assist clinical risk assessment and genetic testing. Methods: Germ-line DNA samples from 727 unrelated probands with positive family history (521 met criteria for familial pancreatic cancer) were tested in compliance with the Clinical Laboratory Improvement Amendments for mutations in BRCA1 and BRCA2 (including analysis of deletions and rearrangements), PALB2, and CDKN2A. We compared prevalence of deleterious mutations between familial pancreatic cancer probands and nonfamilial pancreatic cancer probands (kindreds containing at least two affected biological relatives, but not first-degree relatives). We also examined the impact of family history on breast and ovarian cancers and melanoma. Results: Prevalence of deleterious mutations (excluding variants of unknown significance) among familial pancreatic cancer probands was: BRCA1, 1.2%; BRCA2, 3.7%; PALB2, 0.6%; and CDKN2A, 2.5%. Four novel deleterious mutations were detected. Familial pancreatic cancer probands carry more mutations in the four genes (8.0%) than nonfamilial pancreatic cancer probands (3.5%) (odds ratio: 2.40; 95% confidence interval: 1.06−5.44; P = 0.03). The probability of testing positive for deleterious mutations in any of the four genes ranges up to 10.4%, depending on family history of cancers. BRCA2 and CDKN2A account for the majority of mutations in familial pancreatic cancer. Conclusion: Genetic testing of multiple relevant genes in probands with a positive family history is warranted, particularly for familial pancreatic cancer. Genet Med 17 7, 569–577.

16 December 2014 in Amyloid
Verified
Journal Article
Closed access
PSPaul L. Swiecicki
Paul L. Swiecicki
DZDavid Zhen
David Zhen
MMMichelle L. Mauermann
Michelle L. Mauermann
RKRobert A. Kyle
Robert A. Kyle
SZSteven R. Zeldenrust
Steven R. Zeldenrust
MGMorie A. Gertz
Morie A. Gertz
Hereditary transthyretin amyloidosis (ATTR amyloidosis) is a rare, clinically heterogeneous disease due to heritable mutations that lead to misfolding of a precursor protein and multisystem disease. This study sought to define the clinical characteristics, distribution of mutations and phenotypic presentation of patients presenting to our center with hereditary ATTR amyloidosis. With institutional review board approval, the study retrospectively identified patients who had hereditary ATTR amyloidosis and presented to Mayo Clinic in Rochester, Minnesota, from 1 January 1970, to 29 January 2013. Of the 266 patients with the diagnosis of hereditary ATTR amyloidosis, a pathogenic mutation was identified in 206; the most common mutation was Thr60Ala (68 patients [25%]). Median age at diagnosis was 63.3 years; median survival after diagnosis was 56.8 months (10th-90th percentile, 16.0-297.9). On multivariate analysis, age at diagnosis (risk ratio, 15.65; p < 0.0001), Thr60Ala mutation (risk ratio, 1.52; p = 0.04), Val122Ile mutation (risk ratio, 2.83; p = 0.003), peripheral neuropathy (risk ratio, 1.69; p = 0.013) and weight loss (risk ratio, 1.81; p = 0.002) were risk factors for death. Our data characterize the features of hereditary ATTR amyloidosis in a large cohort, demonstrate the heterogeneity among mutations and support the need to better characterize the clinical progression of individual mutations.

1 June 2016 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
RCRoongruedee Chaiteerakij
Roongruedee Chaiteerakij
GPGloria M. Petersen
Gloria M. Petersen
WBWilliam R. Bamlet
William R. Bamlet
KCKari G. Chaffee
Kari G. Chaffee
DZDavid Zhen
David Zhen
AOAnn L. Oberg
Ann L. Oberg
Purpose: The inclusion of metformin in the treatment arms of cancer clinical trials is based on improved survival that has been demonstrated in retrospective epidemiologic studies; however, unintended biases may exist when analysis is performed by using a conventional Cox proportional hazards regression model with dichotomous ever/never categorization. We examined the impact of metformin exposure definitions, analytical methods, and patient selection on the estimated effect size of metformin exposure on survival in a large cohort of patients with pancreatic ductal adenocarcinoma (PDAC). Patients and Methods: Of newly diagnosed patients with PDAC with diabetes, 980 were retrospectively included, and exposure to metformin documented. Median survival was assessed by using Kaplan-Meier and log-rank methods. Hazard ratios (HR) and 95% CIs were computed to compare time-varying covariate analysis with conventional Cox proportional hazards regression analysis. Results: Median survival of metformin users versus nonusers was 9.9 versus 8.9 months, respectively. By the time-varying covariate analysis, metformin use was not statistically significantly associated with improved survival (HR, 0.93; 95% CI, 0.81 to1.07; P = .28). There was no evidence of benefit in the subset of patients who were naïve to metformin at the time of PDAC diagnosis (most representative of patients enrolled in clinical trials; HR, 1.01; 95% CI, 0.80 to 1.30; P = .89); however, when the analysis was performed by using the conventional Cox model, an artificial survival benefit of metformin was detected (HR, 0.88; 95% CI, 0.77 to 1.01; P = .08), which suggested biased results from the conventional Cox analysis. Conclusion: Our findings did not suggest the benefit of metformin use after patients are diagnosed with PDAC. We highlight the importance of patient selection and appropriate statistical analytical methods when studying medication exposure and cancer survival.

7 October 2014 in Clinical Genetics
Verified
Journal Article
Closed access
PDF file
DZDavid Zhen
David Zhen
PSP.L. Swiecicki
P.L. Swiecicki
SZS.R. Zeldenrust
S.R. Zeldenrust
ADA. Dispenzieri
A. Dispenzieri
MMM.L. Mauermann
M.L. Mauermann
MGM.A. Gertz
M.A. Gertz

10 May 2019 in Analytical Chemistry
Verified
Journal Article
Closed access
EPErica D. Pratt
Erica D. Pratt
RCRobert W. Cowan
Robert W. Cowan
SMSara L. Manning
Sara L. Manning
EQEdmund Qiao
Edmund Qiao
HCHeather Cameron
Heather Cameron
DZDavid Zhen
David Zhen

28 April 2023 in Clinical Cancer Research
Verified
Journal Article
Closed access
PDF file
AMArathi Mohan
Arathi Mohan
KGKent A. Griffith
Kent A. Griffith
FWFulei Wuchu
Fulei Wuchu
DZDavid Zhen
David Zhen
CKChandan Kumar-Sinha
Chandan Kumar-Sinha
VSVaibhav Sahai
Vaibhav Sahai
Purpose: Devimistat (CPI-613) is a novel inhibitor of tumoral mitochondrial metabolism. We investigated the effect of devimistat in vitro and in a phase Ib clinical trial in patients with advanced biliary tract cancer (BTC). Patients and Methods: Cell viability assays of devimistat ± gemcitabine and cisplatin (GC) were performed and the effect of devimistat on mitochondrial respiration via oxygen consumption rate (OCR) was evaluated. A phase Ib/II trial was initiated in patients with untreated advanced BTC. In phase Ib, devimistat was infused over 2 hours in combination with GC on days 1 and 8 every 21 days with a primary objective to determine the recommended phase II dose (RP2D). Secondary objectives included safety, overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Results: In vitro, devimistat with GC had a synergistic effect on two cell lines. Devimistat significantly decreased OCR at higher doses and in arms with divided dosing. In the phase Ib trial, 20 patients received a median of nine cycles (range, 3–19). One DLT was observed, and the RP2D of devimistat was determined to be 2,000 mg/m2 in combination with GC. Most common grade 3 toxicities included neutropenia (n = 11, 55%), anemia (n = 4, 20%), and infection (n = 3, 15%). There were no grade 4 toxicities. After a median follow-up of 15.6 months, ORR was 45% and median PFS was 10 months (95% confidence interval, 7.1–14.9). Median OS is not yet estimable. Conclusions: Devimistat in combination with GC is well tolerated and has an acceptable safety profile in patients with untreated advanced BTC.