Medicine (RMH) - Research Publications

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    Molecular classification of hormone-sensitive and castration-resistant prostate cancer, using nonnegative matrix factorization molecular subtyping of primary and metastatic specimens
    Yuen, KC ; Tran, B ; Anton, A ; Hamidi, H ; Costello, AJ ; Corcoran, NM ; Lawrentschuk, N ; Rainey, N ; Semira, MCG ; Gibbs, P ; Mariathasan, S ; Sandhu, S ; Kadel, EE (WILEY, 2022-06)
    BACKGROUND: Despite the rapidly evolving therapeutic landscape, immunotherapy has demonstrated limited activity in prostate cancer. A greater understanding of the molecular landscape, particularly the expression of immune-related pathways, will inform future immunotherapeutic strategies. Consensus nonnegative matrix factorization (cNMF) is a novel model of molecular classification analyzing gene expression data, focusing on biological interpretation of metagenes and selecting meaningful clusters. OBJECTIVE: We aimed to identify molecular subtypes of prostate cancer using cNMF and correlate these with existing biomarkers to inform future immunotherapeutic strategies. METHODS: A cohort of archival tumor specimens from hormone-sensitive and castration-resistant disease was studied. Whole transcriptomic profiles were generated using TruSeq RNA Access technology and subjected to cNMF. Comprehensive genomic profiling was performed with the FoundationOne assay. NMF subtypes were characterized by gene expression pathways, genomic alterations and correlated with clinical data, then applied to The Cancer Genome Atlas data set. RESULTS: We studied 164 specimens, including 52 castration-resistant and 13 paired primary/metastatic specimens. cNMF identified four distinct subtypes. NMF1 (19%) is enriched for immune-related and stromal-related pathways with transforming growth factor β (TGFβ) signature. NMF2 (36%) is associated with FOXO-mediated transcription signature and AKT signaling, NMF3 (26%) is enriched for ribosomal RNA processing, while NMF4 (19%) is enriched for cell cycle and DNA-repair pathways. The most common gene alterations included TMPRSS22 (42%), TP53 (23%), and DNA-repair genes (19%), occurring across all subtypes. NMF4 is significantly enriched for MYC and Wnt-signaling gene alterations. TMB, CD8 density, and PD-L1 expression were low overall. NMF1 and NMF4 were NMF2 was associated with superior overall survival. CONCLUSIONS: Using cNMF, we identified four molecularly distinct subtypes which may inform treatment selection. NMF1 demonstrates the most inflammatory signature with asuppressive TGFβ signature, suggesting potential benefit with immunotherapy combination strategies targeting TGFβ and PD-(L)1. Prospective studies are required to evaluate the use of this novel model to molecularly stratify patients for optimal treatment selection.
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    Fournier's gangrene in a man on empagliflozin for treatment of Type2 diabetes
    Kumar, S ; Costello, AJ ; Colman, PG (WILEY, 2017-11)
    BACKGROUND: Sodium-glucose cotransporter 2 (SLGT2) inhibitors has been associated with an increased risk of genital infections secondary to increased glycosuria. CASE REPORT: We report a case of a 41-year-old man with type 2 diabetes treated with empagliflozin and metformin who presented with scrotal swelling. He described multiple preceding episodes of genital thrush for which he self-administered over-the-counter anti-fungal treatment. On examination, he was afebrile and hemodynamically stable. Perineal examination revealed grossly swollen and indurated scrotum with bilateral inguinal lymphadenopathy. Investigations showed elevated inflammatory markers and HbA1c of 99 mmol/mol (11.2%). Computed tomography revealed features consistent with Fournier's gangrene. He underwent emergency exploration and debridement under anaesthetic with a later return to theatre for further exploration, washout and application of a vacuum dressing. He then received a split skin graft to his perineum. He required a 2-week course of intravenous antibiotics and was discharged home on oral antibiotics. Empagliflozin was ceased on admission and he was commenced on a basal bolus insulin regimen for glycaemic optimisation. CONCLUSION: There is a wide clinical spectrum of genital infections associated with SGLT2 inhibitors with most being generally mild and easily treated. However, risk factors such as diabetes, obesity, immunosuppressed states, smoking, alcohol abuse and end-stage renal or liver failure may increase the risk of potentially more severe infections such as Fournier's gangrene. Timely cessation of SGLT2 inhibitors in individuals with multiple risk factors may help prevent progression to more severe genital infections.
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    Positive surgical margins: rate, contributing factors and impact on further treatment: findings from the Prostate Cancer Registry
    Evans, SM ; Millar, JL ; Frydenberg, M ; Murphy, DG ; Davis, ID ; Spelman, T ; Bolton, DM ; Giles, GG ; Dean, J ; Costello, AJ ; Frauman, AG ; Kearns, PA ; Day, L ; Daniels, C ; McNeill, JJ (WILEY, 2014-11)
    OBJECTIVE: To describe the characteristics of patients with and without positive surgical margins (PSMs) and to analyse the impact of PSMs on secondary cancer treatment after radical prostatectomy (RP), with short-term follow-up. PATIENTS AND METHODS: We analysed data from 2385 consecutive patients treated using RP, who were notified to the Prostate Cancer Registry by 37 hospitals in Victoria, Australia between August 2008 and February 2012. Independent and multivariate models were constructed to predict the likelihood of PSMs. Independent and multivariate predictors of secondary treatment after RP in the initial 12 months after diagnosis were also assessed. RESULTS: Data on PSM status were collected for 2219/2385 (93%) patients. In total 592/2175 (27.2%) RPs resulted in PSMs; 102/534 (19.1%) in the low-risk group, 317/1218 (26.0%) in the intermediate-risk group, 153/387 (39.5%) in the high-risk group, and 9/11 (81.8%) in the very-high-risk disease group of patients. Patients having surgery in a hospital where <10 RPs occur each year were significantly more likely to have a PSM (incidence rate ratio [IRR] 1.44, 95% confidence interval [CI] 1.07-1.93) and those in the intermediate-, high- or very-high-risk groups (IRR 1.34, 95% CI 1.09-1.65, P = 0.007, IRR 1.96, 95% CI 1.57-2.45, P < 0.001 and IRR 3.81, 95% CI 2.60-5.60, P < 0.001, respectively) were significantly more likely to have a PSM than those in the low-risk group (IRR 2.50, 95% CI 1.23-5.11, P = 0.012). Patients with PSMs were significantly less likely to have been treated at a private hospital than a public hospital (IRR 0.76, 95% CI 0.63-0.93, P = 0.006) or to have undergone robot-assisted RP (IRR 0.69, 95% CI 0.55-0.87; P = 0.002) than open RP. Of the 2182 patients who underwent RP in the initial 12 months after diagnosis, 1987 (91.1%) received no subsequent treatment, 123 (5.6%) received radiotherapy, 47 (2.1%) received androgen deprivation therapy (ADT) and 23 (1.1%) received a combination of radiotherapy and ADT. Two patients (0.1%) received chemotherapy combined with another treatment. At a multivariate level, predictors of additional treatment after RP in the initial 12 months included having a PSM compared with a negative surgical margin (odds ratio [OR] 5.61, 95% CI 3.82-8.22, P < 0.001); pT3 compared with pT2 disease (OR 4.72, 95% CI 2.69-8.23, P < 0.001); and having high- or very-high-risk disease compared with low-risk disease (OR 4.36, 95% CI 2.24-8.50, P < 0.001 and OR 4.50, 95% CI 1.34-15.17, P = 0.015, respectively). Patient age, hospital location and hospital type were not associated with secondary treatment. Patients undergoing robot-assisted RP were significantly less likely to receive additional treatment than those receiving open RP (OR 0.59, 95% CI 0.39-0.88, P = 0.010). CONCLUSIONS: These data indicate an important association between hospital status and PSMs, with patients who underwent RP in private hospitals less likely than those in public hospitals to have a PSM. Patients treated in lower-volume hospitals were more likely to have a PSM and less likely to receive additional treatment after surgery in the initial 12 months, and robot-assisted RP was associated with fewer PSMs than was open RP in this non-randomized observational study. PSM status and pathological T3 disease are both important and independent predictors of secondary cancer treatment for patients undergoing RP. A robot-assisted RP approach appears to decrease the likelihood of subsequent treatment, when compared with the open approach.
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    Abstracts of 4th World Robotic Urology Symposium, Orlando, Florida, 6-8 April 2009.
    Murphy, DG ; Challacombe, B ; COSTELLO, A (Springer Science and Business Media LLC, 2009-06)
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    Robotic assisted radical prostatectomy in older men
    Challacombe, B ; Kyle, C ; Bradford, T ; Murphy, D ; Peters, J ; Kerger, M ; COSTELLO, A ( 2009)
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    Salvage robotic-assisted laparoscopic radical prostatectomy following failed primary high-intensity focussed ultrasound treatment for localised prostate cancer
    Murphy, DG ; Pedersen, J ; Costello, AJ (SPRINGER LONDON LTD, 2008-09)
    We report the first case of salvage robotic-assisted laparoscopic radical prostatectomy (RALP) following failed primary high-intensity focussed ultrasound (HIFU) for localised carcinoma of the prostate. A 66-year-old male with a presenting prostate-specific antigen (PSA) of 5 ng/ml was diagnosed with T1c Gleason 3 + 4 prostate cancer. He underwent transurethral resection of the prostate and HIFU. His PSA dropped to 2.0 ng/ml and repeat biopsy revealed upgrading of his prostate cancer to Gleason 4 + 3. He was referred to us for a second opinion and, following discussion of his options, he underwent RALP. The total operative time was 159 min. There were no intra- or postoperative complications. He was discharged on postoperative day two and was fully continent 10 days following removal of his catheter. His PSA remained undetectable 6 months postoperatively. Salvage RALP was feasible in this case with good functional and short-term oncological outcomes for the patient.
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    High prostatic fascia release or standard nerve sparing? A viewpoint from the Royal Melbourne Hospital
    Murphy, DG ; Costello, AJ (SPRINGER LONDON LTD, 2008-09)
    Radical prostatectomy with preservation of the neurovascular bundles (NVB) is a treatment option for localised prostate cancer in selected patients. An interesting debate has developed about the precise technique used to preserve these nerves. The standard technique releases the NVB from the postero-lateral groove between the prostate and rectum. A new technique, dubbed the "veil of Aphrodite" technique, proposes a higher release of the lateral prostatic fascia on the presumption that cavernosal nerves exist in this area. We have reviewed the evidence for the anatomical basis of nerve-sparing radical prostatectomy, particularly with respect to the standard versus the "veil" technique of radical prostatectomy. Microdissections of the NVB in cadaveric specimens have confirmed the course of the cavernosal nerves in the postero-lateral groove between the prostate and rectum. Though studies have also demonstrated nerves higher in the lateral prostatic fascia, these are likely to innervate the prostate rather than the cavernosal tissues. Though excellent potency results have been reported for the "veil" technique from one institution, there is not sufficient anatomical evidence to support this technique over the standard technique of nerve-sparing radical prostatectomy.