ORCID Profile
0000-0002-6801-0841
Current Organisations
Chris O'Brien Lifehouse
,
Garvan Institute of Medical Research
,
Royal Prince Alfred Hospital
,
University of Sydney
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Publisher: Wiley
Date: 30-07-2016
DOI: 10.1002/PROS.23233
Abstract: Positive surgical margins (PSMs) in localized prostate cancer (PC) confer a two- to three-fold increased risk of biochemical relapse (BR). Absent/weak AZGP1 expression and Gleason grade ≥4 at the margin are each independent predictors of BR in patients with PSMs. Our study aimed to determine whether the biomarkers AZGP1 expression and Gleason grade at the site of a PSM are significant independent markers of biochemical and clinical relapse (CR) when modeled together and whether one of these biomarkers may be superior in its capacity to predict outcome. A cohort of 275 consecutive patients with margin-positive localized PC following surgery were assessed for Gleason grade and AZGP1 expression at the PSM. BR-free survival was the primary end-point, while CR-free survival and PC-specific death were secondary endpoints. Kaplan-Meier Analysis and Cox Proportional Hazards Modeling were performed. Absent AZGP1 expression was significantly associated with increased risk of BR (P = 0.001) and PC-specific death (P = 0.02). Gleason grade ≥4 at PSM was associated with BR (P = 0.02), CR (P = 0.003), and PC-specific death (P = 0.004). On multivariable analysis, absent AZGP1 expression remained an independent predictor of BR (HR 2.4, 95%CI 1.5-3.9, P < 0.001) when modeled with Gleason grade at margin (HR 1.3, 95%CI 0.9-1.9, P = 0.16), preoperative PSA (P = 0.002), seminal vesicle involvement (P = 0.002), extraprostatic extension (P = 0.001), Gleason score (P = 0.01), adjuvant treatment (P = 0.75), linear length of the involved margin (P = 0.001) and margin number (P = 0.09). Absent AZGP1 expression is an independent predictor of BR in margin-positive localized PC and is associated with increased PC-specific mortality in a Phase II study. Absent AZGP1 expression was superior to Gleason grade at PSM in predicting relapse and should be incorporated into subsequent clinical trials of post-operative radiotherapy in men with margin-positive PC. Prostate 76:1491-1500, 2016. © 2016 Wiley Periodicals, Inc.
Publisher: Impact Journals, LLC
Date: 25-05-2017
Publisher: Wiley
Date: 19-02-2022
DOI: 10.1111/AJCO.13552
Abstract: Colorectal cancer remains the third most common malignancy in Australia with the peritoneum being the second most common metastatic site. Colorectal peritoneal carcinomatosis (CPC) can be treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy but this is only limited to a small subset of patients. Those with inoperable disease have a particularly poor prognosis. While the ideal systemic regimen has not been defined, 5-fluorouracil-based chemotherapy regimens appear to provide overall and progression free survival benefits. The role of targeted agents such as bevacizumab (vascular endothelial growth factor inhibitor) or cetuximab (epidermal growth factor inhibitor) in the setting of CPC is still evolving. Currently, retrospective analyses have shown promising results for the use of bevacizumab in addition to systemic chemotherapy but similar results have not been seen with cetuximab or panitumumab. However, there is significant heterogeneity in the trial data, lack of prospective randomized controlled trials and demonstrated treatment variability based on age and tumour characteristics. This review summarises the current literature in regard to treatment in the unresectable CPC setting as well as discussing issues with the current data and highlighting the need for further trials.
Publisher: SAGE Publications
Date: 2022
DOI: 10.1177/17588359221092486
Abstract: To determine the efficacy and safety of intermittent docetaxel chemotherapy guided by circulating methylated glutathione S-transferase Pi-1 ( mGSTP1) in men with metastatic castration-resistant prostate cancer (CRPC). GUIDE (NCT04918810) is a randomised, two-arm, non-comparative phase-2 trial recruiting 120 patients at six Australian centres. Patients with Prostate Cancer Working Group-3 defined metastatic CRPC who are commencing docetaxel 75 mg/m 2 q3w will be pre-screened for detectable mGSTP1 at baseline ± following two cycles of treatment. Those with detectable plasma mGSTP1 at baseline that becomes undetectable after two cycles of chemotherapy will be eligible for GUIDE. Prior to Cycle 4 of docetaxel, these patients are randomised 2:1 to one of two treatment arms: Arm A (cease docetaxel and reinstitute if mGSTP1 becomes detectable) or Arm B (continue docetaxel 75 mg/m 2 q3w in accordance with clinician’s usual practice). The primary endpoint is radiographic progression-free survival. Secondary endpoints include time on treatment holidays, safety, patient-reported outcomes, overall survival, health resource use, and cost associated with treatment. Enrolment commenced November 2021. The results of this trial will generate data on the clinical utility of mGSTP1 as a novel biomarker to guide treatment de-escalation in metastatic CRPC.
Publisher: Springer Science and Business Media LLC
Date: 08-04-2014
DOI: 10.1038/BJC.2014.181
Publisher: Springer Science and Business Media LLC
Date: 31-03-2015
DOI: 10.1038/BJC.2015.74
Publisher: Springer Science and Business Media LLC
Date: 09-03-2017
DOI: 10.1038/BJC.2017.50
Publisher: Wiley
Date: 08-08-2017
DOI: 10.1002/IJC.30903
Abstract: Lipids are known to influence tumour growth, inflammation and chemoresistance. However, the association of circulating lipids with the clinical outcome of metastatic castration-resistant prostate cancer (CRPC) is unknown. We investigated associations between the plasma lipidome and clinical outcome in CRPC. Lipidomic profiling by liquid chromatography-tandem mass spectrometry was performed on plasma s les from a Phase 1 discovery cohort of 96 CRPC patients. Results were validated in an independent Phase 2 cohort of 63 CRPC patients. Unsupervised analysis of lipidomic profiles (323 lipid species) classified the Phase 1 cohort into two patient subgroups with significant survival differences (HR 2.31, 95% CI 1.44-3.68, p = 0.0005). The levels of 46 lipids were in idually prognostic and were predominantly sphingolipids with higher levels associated with poor prognosis. A prognostic three-lipid signature was derived (ceramide d18:1/24:1, sphingomyelin d18:2/16:0, phosphatidylcholine 16:0/16:0) and was also associated with shorter survival in the Phase 2 cohort (HR 4.8, 95% CI 2.06-11.1, p = 0.0003). The signature was an independent prognostic factor when modelled with clinicopathological factors or metabolic characteristics. The association of plasma lipids with CRPC prognosis suggests a possible role of these lipids in disease progression. Further research is required to determine if therapeutic modulation of the levels of these lipids by targeting their metabolic pathways may improve patient outcome.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.EURURO.2018.01.007
Abstract: In 2014, a landmark study was published demonstrating that the expression of androgen receptor splice variant (AR-V) 7 was a negative predictive biomarker for response to abiraterone acetate and enzalutamide in metastatic castration-resistant prostate cancer (mCRPC) patients. However, these results were not supported by the recently reported ARMOR3-SV phase III clinical trial, which employed an identical circulating tumour cell assay to assess AR-V7 expression. Therefore, the predictive utility of AR-V7 expression in mCRPC remains uncertain, as does any potential association between other AR-Vs and treatment response. To further investigate, we designed a highly sensitive and specific whole blood assay for detecting AR-V7 and AR-V9. We then examined for a correlation between baseline AR-V7/V9 status and treatment outcome in 37 mCRPC patients commencing abiraterone or enzalutamide. Of the patients, 24% (9/37) were AR-V-positive. Notably, prostate-specific antigen (PSA) response rates did not significantly differ between AR-V-positive (6/9) and AR-V-negative (18/28) patients (66% vs 64%, p=0.9). Likewise, median PSA progression-free survival was not significantly different between AR-V-positive and AR-V-negative patients (9.2 mo vs not reached p=0.9). These data, which support the findings of the pivotal ARMOR3-SV clinical trial, suggest that baseline AR-V expression does not predict outcomes in mCRPC patients receiving abiraterone or enzalutamide. Detection of androgen receptor splice variants (AR-Vs) in circulating tumour cells of advanced prostate cancer patients has been linked to resistance to abiraterone and enzalutamide. We designed a blood test to detect AR-Vs that can be performed more routinely than tests involving circulating tumour cells and found that patients with AR-Vs still benefit from these effective treatments.
Publisher: Wiley
Date: 04-12-2018
DOI: 10.1002/IJC.31906
Publisher: SAGE Publications
Date: 2022
DOI: 10.1177/17588359221112478
Abstract: Appendiceal cancer is rare and encompasses a erse group of tumours ranging from low-grade appendiceal mucinous neoplasms to high-grade adenocarcinomas. Appendiceal cancers often spread to the peritoneal cavity causing extensive mucinous dissemination and peritoneal metastases. Prognosis varies with histological subtype. Cytoreductive surgery and heated intraperitoneal chemotherapy is well-established as the most effective treatment achieving long-term survival in some patients. Chemotherapy regimens used to treat appendiceal cancer are extrapolated from the colorectal cancer setting, but disease biology differs and outcomes are inferior. The role of chemotherapy in the treatment of appendiceal cancer remains poorly defined. There is an urgent need to develop novel tailored treatment strategies in the perioperative and unresectable setting. This review aims to evaluate the literature for patients who received intraperitoneal and systemic chemotherapy for appendiceal cancers.
Publisher: IEEE
Date: 11-2015
Publisher: Bioscientifica
Date: 13-01-2016
DOI: 10.1530/ERC-15-0369
Abstract: Circulating tumor DNA (ctDNA) in the plasma or serum of cancer patients provides an opportunity for non-invasive s ling of tumor DNA. This ‘liquid biopsy’ allows for interrogations of DNA such as quantity, chromosomal alterations, sequence mutations and epigenetic changes, and can be used to guide and improve treatment throughout the course of the disease. This tremendous potential for real-time ‘tracking’ in a cancer patient has led to substantial research efforts in the ctDNA field. ctDNA can be distinguished from non-tumor DNA by the presence of tumor-specific mutations and copy number variations, and also by aberrant DNA methylation, with both DNA sequence and methylation changes corresponding to those found in the tumor. Aberrant methylation of specific promoter regions can be a very consistent feature of cancer, in contrast to mutations, which typically occur at a wide range of sites. This consistency makes ctDNA methylation amenable to the design of widely applicable clinical assays. In this review, we examine ctDNA methylation in the context of monitoring disease status, treatment response and determining the prognosis of cancer patients.
Publisher: Springer Science and Business Media LLC
Date: 21-08-2014
DOI: 10.1038/BJC.2014.463
Publisher: American Society of Clinical Oncology (ASCO)
Date: 07-2023
DOI: 10.1200/JCO.22.02895
Publisher: Elsevier BV
Date: 08-2017
Abstract: Prostate cancers (PCs) with similar characteristics at the time of diagnosis can have very different disease outcomes. Conventional biomarkers of PC still lack precision in identifying in iduals at high risk of PC recurrence. While many candidate biomarkers are proposed in the literature, few are in clinical practice as they lack rigorous validation. This study prospectively enrolled an independent phase III cohort to evaluate the clinical utility of zinc-alpha 2-glycoprotein (AZGP1) as a prognostic biomarker in localized PC. In our multicentre, prospective phase III study, AZGP1 status in 347 radical prostatectomy specimens was assayed by immunohistochemistry in a NATA-accredited laboratory. The AZGP1 score was assessed in a multivariable model incorporating established prognostic factors. We also report extended outcomes from our previous phase II study. The primary endpoint was biochemical relapse-free survival (BRFS). Secondary endpoints were metastasis-free survival (MFS) and PC-specific survival (PCSS). In the phase II cohort, with a median follow-up of 15.8 years, low/absent AZGP1 expression was an independent predictor of poor BRFS (HR, 1.4 95% CI, 1.1-1.9 P = 0.03), MFS (HR, 2.8 95% CI, 1.2-6.6 P = 0.02) and PCSS (HR, 3.8 95% CI, 1.5-9.5 P = 0.005). These results were validated in our prospective phase III cohort. Low/absent AZGP1 expression independently predicted for BRFS (HR, 1.9 95% CI, 1.1-3.3 P = 0.02), with shorter MFS (HR, 2.0 95% CI, 1.1-3.4 P = 0.02). AZGP1 improved the discriminatory value when incorporated into existing prognostic risk models. Our study provides prospective phase III validation that absent/low AZGP1 expression provides independent prognostic value in PC. This study provides robust evidence for the incorporation of this biomarker into clinical practice.
Publisher: Bioscientifica
Date: 12-05-2011
DOI: 10.1530/ERC-10-0343
Abstract: Chemotherapy remains the major treatment option for castration-resistant prostate cancer (CRPC) and limited cytotoxic options are available. Inherent chemotherapy resistance occurs in half of all patients and inevitably develops even in those who initially respond. Docetaxel has been the mainstay of therapy for 6 years, providing a small survival benefit at the cost of significant toxicity. Cabazitaxel is a promising second-line agent however, it is no less toxic, whereas mitoxantrone provides only symptomatic benefit. Multiple cellular pathways involving apoptosis, inflammation, angiogenesis, signalling intermediaries, drug efflux pumps and tubulin are implicated in the development of chemoresistance. A thorough understanding of these pathways is needed to identify biomarkers that predict chemotherapy resistance with the aim to avoid unwarranted toxicities in patients who will not benefit from treatment. Until recently, the search for predictive biomarkers has been disappointing however, the recent discovery of macrophage inhibitory cytokine 1 as a marker of chemoresistance may herald a new era of biomarker discovery in CRPC. Understanding the interface between this complex array of chemoresistance pathways rather than their study in isolation will be required to effectively predict response and target the late stages of advanced disease. The pre-clinical evidence for these resistance pathways and their progress through clinical trials as therapeutic targets is reviewed in this study.
Publisher: Wiley
Date: 30-04-2017
DOI: 10.1111/BJU.13857
Abstract: To assess the relationship between the International Society of Urological Pathology (ISUP) 2014 grading system, biochemical recurrence (BCR) and clinical recurrence (CLR) after radical prostatectomy (RP), to determine whether the 2014 ISUP grading system is a better predictor of survival compared with the previous Gleason scoring systems, and to investigate whether incorporation of the tertiary pattern/grade into the ISUP scoring system significantly improves its efficacy. A total of 635 RP cases (1991-1999) were identified from a database at a single institution. A histopathology review was performed to re-grade the cases as per the ISUP 2014 grading system. All relevant clinicopathological data and clinical follow-up (median [range] 15.25 [0.3-26] years) were obtained. Log-rank, Kaplan-Meier, Cox regression and Harrell's concordance c-indices analyses were performed. At a median follow-up of 15 years, 276 patients (44%) had BCR and 41 (7%) had CLR. Grade Groups 1, 2, 3, 4 and 5 were seen in 112 (18%), 307 (48%), 129 (20%), 33 (5%) and 54 patients (9%), respectively: 337 (53%) were upgraded, while 70 (11%) were downgraded compared with the 1992 Gleason system. Grade Group (hazard ratio [HR] 4.9 P < 0.001) and preoperative prostate-specific antigen (PSA) level (HR 1.4 P < 0.001) were independent predictors of BCR. Only Grade Group 5 (HR 12.3 P = 0.02), preoperative PSA (HR 1.6 P < 0.001), stage pT3b (HR 3.1 P = 0.03) and pT4 (HR 12.4 P < 0.001) independently predicted CLR. Harrell's c-indices showed that the 2014 ISUP grading system was a significantly better predictor of BCR and CLR as well as prostate cancer-specific death, compared with the 2005 ISUP modified Gleason system. The replacement of the secondary pattern by the tertiary pattern did not alter the prognostic efficacy of the ISUP 2014 grading system. The ISUP 2014 grading system is a significant independent predictor of both BCR and CLR, outperforming the 2005 ISUP modified Gleason system. This classification system has the potential to influence clinical decision-making after RP.
No related grants have been discovered for Kate Mahon.