Gregory Chesnut

Dr. Gregory Chesnut


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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Verified
Journal Article
Open access
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BBBrock E. Boehm
Brock E. Boehm
MYMonica Ellis York
Monica Ellis York
GPGyorgy Petrovics
Gyorgy Petrovics
IKIndu Kohaar
Indu Kohaar
GCGregory Chesnut
Gregory Chesnut
In the United States, prostate cancer (CaP) remains the second leading cause of cancer deaths in men. CaP is predominantly indolent at diagnosis, with a small fraction (25–30%) representing an aggressive subtype (Gleason score 7–10) that is prone to metastatic progression. This fact, coupled with the criticism surrounding the role of prostate specific antigen in prostate cancer screening, demonstrates the current need for a biomarker(s) that can identify clinically significant CaP and avoid unnecessary biopsy procedures and psychological implications of being diagnosed with low-risk prostate cancer. Although several diagnostic biomarkers are available to clinicians, very few comparative trials have been performed to assess the clinical effectiveness of these biomarkers. It is of note, however, that a majority of these clinical trials have been over-represented by men of Caucasian origin, despite the fact that African American men have a 1.7 times higher incidence and 2.1 times higher rate of mortality from prostate cancer. Biomarkers for CaP diagnosis based on the tissue of origin include urine-based gene expression assays (PCA3, Select MDx, ExoDx Prostate IntelliScore, Mi-Prostate Score, PCA3-PCGEM1 gene panel), blood-based protein biomarkers (4K, PHI), and tissue-based DNA biomarker (Confirm MDx). Another potential direction that has emerged to aid in the CaP diagnosis include multi-parametric magnetic resonance imaging (mpMRI) and bi-parametric magnetic resonance imaging (bpMRI), which in conjunction with clinically validated biomarkers may provide a better approach to predict clinically significant CaP at diagnosis. In this review, we discuss some of the adjunctive biomarker tests along with newer imaging modalities that are currently available to help clinicians decide which patients are at risk of having high-grade CaP on prostate biopsy with the emphasis on clinical utility of the tests across African American (AA) and Caucasian (CA) men.

9 October 2023 in Cancers
Verified
Journal Article
Open access
PDF file
GBGartrell C Bowling
Gartrell C Bowling
PSPiragash Swargaloganathan
Piragash Swargaloganathan
CHCarly Heintz
Carly Heintz
RMRavi Madan
Ravi Madan
BEBinil Eldhose
Binil Eldhose
GCGregory Chesnut
Gregory Chesnut
Background: Poly ADP-ribose polymerase inhibitors (PARPis) are an important class of therapeutics for metastatic castration-resistant prostate cancer (mCRPC). Unlike hormone-based treatments for mCRPC, PARPis are not without drug-related hematological adverse events. Objective: To review the evidence on hematological toxicities, including anemia, thrombocytopenia, and neutropenia from PARPis in prostate cancer. Study Methodology: A systematic review and meta-analysis using the PRISMA guidelines was performed for phase II and III randomized controlled trials (RCTs) of PARPis in prostate cancer. PubMed, Embase, and Ovid All EBM reviews—Cochrane were queried from inception to 9 June 2023. The Mantel–Haenszel method was used to report risk ratios (RR) and 95% confidence intervals (CI) for all-grade and high-grade anemia, thrombocytopenia, and neutropenia toxicities. Results: The systematic review retrieved eight phase II and III RCTs; specifically, eight were included in the anemia, five in the all-grade thrombocytopenia and neutropenia, and four in the high-grade thrombocytopenia and neutropenia outcomes. Compared to a placebo and/or other non-PARPi treatments, PARPi use was associated with an increased risk of all-grade anemia (RR, 3.37; 95% CI, 2.37–4.79; p < 0.00001), thrombocytopenia (RR, 4.54; 95% CI, 1.97–10.44; p = 0.0004), and neutropenia (RR, 3.11; 95% CI, 1.60–6.03; p = 0.0008). High-grade anemia (RR, 6.94; 95% CI, 4.06–11.86; p < 0.00001) and thrombocytopenia (RR, 5.52; 95% CI, 2.80–10.88; p < 0.00001) were also associated with an increased risk, while high-grade neutropenia (RR, 3.63; 95% CI, 0.77–17.23; p = 0.10) showed no significant association. Subgroup stratification analyses showed differences in various all-grade and high-grade toxicities. Conclusion: PARPis were associated with an increased risk of hematological AEs. Future studies with more pooled RCTs will enhance this understanding and continue to inform patient–physician shared decision-making. Future studies may also have a role in improving the current management strategies for these AEs.

9 May 2023 in Biomedicines
Verified
Journal Article
Open access
PDF file
ADAllison Duncan
Allison Duncan
DNDarryl Nousome
Darryl Nousome
RRRandy Ricks
Randy Ricks
HKHuai-Ching Kuo
Huai-Ching Kuo
LRLakshmi Ravindranath
Lakshmi Ravindranath
IKIndu Kohaar
Indu Kohaar
Growing evidence indicates the involvement of a genetic component in prostate cancer (CaP) susceptibility and clinical severity. Studies have reported the role of germline mutations and single nucleotide polymorphisms (SNPs) of TP53 as possible risk factors for cancer development. In this single institutional retrospective study, we identified common SNPs in the TP53 gene in AA and CA men and performed association analyses for functional TP53 SNPs with the clinico-pathological features of CaP. The SNP genotyping analysis of the final cohort of 308 men (212 AA; 95 CA) identified 74 SNPs in the TP53 region, with a minor allele frequency (MAF) of at least 1%. Two SNPs were non-synonymous in the exonic region of TP53: rs1800371 (Pro47Ser) and rs1042522 (Arg72Pro). The Pro47Ser variant had an MAF of 0.01 in AA but was not detected in CA. Arg72Pro was the most common SNP, with an MAF of 0.50 (0.41 in AA; 0.68 in CA). Arg72Pro was associated with a shorter time to biochemical recurrence (BCR) (p = 0.046; HR = 1.52). The study demonstrated ancestral differences in the allele frequencies of the TP53 Arg72Pro and Pro47Ser SNPs, providing a valuable framework for evaluating CaP disparities among AA and CA men.

18 February 2025 in Cancers
Verified
Journal Article
Open access
PDF file
BBBorbiev Borbiev
Borbiev Borbiev
KBKevin Babcock
Kevin Babcock
KSKayleigh Sinopole
Kayleigh Sinopole
GCGregory Chesnut
Gregory Chesnut
GPGyorgy Petrovics
Gyorgy Petrovics
This review is intended to reflect the currently available literature on both clinically significant germline mutations in DNA damage repair (DDR) genes as well as the importance of ancestral diversity in the pathogenesis of prostate cancer (PCa). The second most prevalent cancer worldwide in men is PCa, causing significant morbidity and mortality in its advanced stage. Emerging data highlight the substantial role of germline mutations of DDR genes in PCa pathogenesis, especially in progression to aggressive forms of the disease. Germline genetic testing is recognized as a necessary tool for efficient, individualized patient care. NCCR guidelines recommend inquiring about the family history of PCa and known germline variants and, if indicated, proceeding with germline multigene testing followed by post-test genetic counseling. Depending on the germline mutations in HR repair genes or in MMR genes, specific treatment options may provide clinical benefit. We will discuss specific germline mutations that are involved in PCa progression and prognosis in racially diverse populations.

17 April 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
ADAllison Duncan
Allison Duncan
DNDarryl Nousome
Darryl Nousome
RRRandy Ricks
Randy Ricks
HKHuai-Ching Kuo
Huai-Ching Kuo
LRLakshmi Ravindranath
Lakshmi Ravindranath
IKIndu Kohaar
Indu Kohaar
Growing evidence indicates the involvement of a genetic component for CaP susceptibility and clinical severity. Somatic mutations of TP53 have been associated with 50% of diverse human cancers. Studies have also reported the role of germ line mutations and single nucleotide poly-morphisms (SNPs) of TP53 as possible risk factors for cancer development. In this single De-partment of Defense institutional retrospective study, we identified common SNPs in the TP53 gene in AA and CA men and performed association analyses for functional TP53 SNPs with clinico-pathological features of CaP. The CPDR Oncoarray database on blood derived genomic DNA from 321 men treated by radical prostatectomy at WRNMMC were used to examine clini-co-pathological associations with TP53 SNPs. The SNP genotyping analysis on the final cohort of 308 patients (212 AA; 95 CA) identified 74 SNPs in the TP53 gene region with a minor allele fre-quency (MAF) of at least 1%. Two SNPs were non-synonymous in the exonic region of TP53: rs1800371 (Pro47Ser) and rs1042522 (Arg72Pro). The Pro47Ser variant, had a minor allele frequency of 0.01 in AA, however, was not detected in CA. Arg72Pro was the most common SNP with a minor allele frequency of 0.50 (0.41 in AA; 0.68 in CA). Additionally, Arg72Pro was associated with time to biochemical recurrence (BCR) after statistical adjustment for patient age at diagnosis, self-reported race, and Gleason score (p= 0.046; HR = 1.52). The present study demonstrated ancestral differences in allele frequencies of TP53 Arg72Pro and Pro47Ser SNPs in AA and CA CaP, providing a valuable framework for the interrogating CaP disparity among AA and CA men.