Surgery (RMH) - Research Publications
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ItemTranscriptome sequencing and multi-plex imaging of prostate cancer microenvironment reveals a dominant role for monocytic cells in progression(BMC, 2021-07-22)BACKGROUND: Prostate cancer is caused by genomic aberrations in normal epithelial cells, however clinical translation of findings from analyses of cancer cells alone has been very limited. A deeper understanding of the tumour microenvironment is needed to identify the key drivers of disease progression and reveal novel therapeutic opportunities. RESULTS: In this study, the experimental enrichment of selected cell-types, the development of a Bayesian inference model for continuous differential transcript abundance, and multiplex immunohistochemistry permitted us to define the transcriptional landscape of the prostate cancer microenvironment along the disease progression axis. An important role of monocytes and macrophages in prostate cancer progression and disease recurrence was uncovered, supported by both transcriptional landscape findings and by differential tissue composition analyses. These findings were corroborated and validated by spatial analyses at the single-cell level using multiplex immunohistochemistry. CONCLUSIONS: This study advances our knowledge concerning the role of monocyte-derived recruitment in primary prostate cancer, and supports their key role in disease progression, patient survival and prostate microenvironment immune modulation.
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ItemLoss of SNAI2 in Prostate Cancer Correlates With Clinical Response to Androgen Deprivation Therapy(LIPPINCOTT WILLIAMS & WILKINS, 2021-06)PURPOSE: Androgen receptor (AR) signaling is important in prostate cancer progression, and therapies that target this pathway have been the mainstay of treatment for advanced disease for over 70 years. Tumors eventually progress despite castration through a number of well-characterized mechanisms; however, little is known about what determines the magnitude of response to short-term pathway inhibition. METHODS: We evaluated a novel combination of AR-targeting therapies (degarelix, abiraterone, and bicalutamide) and noted that the objective patient response to therapy was highly variable. To investigate what was driving treatment resistance in poorly responding patients, as a secondary outcome we comprehensively characterized pre- and post-treatment samples using both whole-genome and RNA sequencing. RESULTS: We find that resistance following short-term treatment differs molecularly from typical progressive castration-resistant disease, associated with transcriptional reprogramming, to a transitional epithelial-to-mesenchymal transition (EMT) phenotype rather than an upregulation of AR signaling. Unexpectedly, tolerance to therapy appears to be the default state, with treatment response correlating with the prevalence of tumor cells deficient for SNAI2, a key regulator of EMT reprogramming. CONCLUSION: We show that EMT characterizes acutely resistant prostate tumors and that deletion of SNAI2, a key transcriptional regulator of EMT, correlates with clinical response.
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ItemDetection of ctDNA in plasma of patients with clinically localised prostate cancer is associated with rapid disease progression(BMC, 2020-08-17)BACKGROUND: DNA originating from degenerate tumour cells can be detected in the circulation in many tumour types, where it can be used as a marker of disease burden as well as to monitor treatment response. Although circulating tumour DNA (ctDNA) measurement has prognostic/predictive value in metastatic prostate cancer, its utility in localised disease is unknown. METHODS: We performed whole-genome sequencing of tumour-normal pairs in eight patients with clinically localised disease undergoing prostatectomy, identifying high confidence genomic aberrations. A bespoke DNA capture and amplification panel against the highest prevalence, highest confidence aberrations for each individual was designed and used to interrogate ctDNA isolated from plasma prospectively obtained pre- and post- (24 h and 6 weeks) surgery. In a separate cohort (n = 189), we identified the presence of ctDNA TP53 mutations in preoperative plasma in a retrospective cohort and determined its association with biochemical- and metastasis-free survival. RESULTS: Tumour variants in ctDNA were positively identified pre-treatment in two of eight patients, which in both cases remained detectable postoperatively. Patients with tumour variants in ctDNA had extremely rapid disease recurrence and progression compared to those where variants could not be detected. In terms of aberrations targeted, single nucleotide and structural variants outperformed indels and copy number aberrations. Detection of ctDNA TP53 mutations was associated with a significantly shorter metastasis-free survival (6.2 vs. 9.5 years (HR 2.4; 95% CIs 1.2-4.8, p = 0.014). CONCLUSIONS: CtDNA is uncommonly detected in localised prostate cancer, but its presence portends more rapidly progressive disease.
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ItemThe modified International Society of Urological Pathology system improves concordance between biopsy and prostatectomy tumour grade(WILEY, 2021-12)OBJECTIVES: To assess the concordance between biopsy and radical prostatectomy (RP) specimens using the 2005 Gleason score (GS) and the International Society of Urological Pathology (ISUP) 2014/World Health Organization 2016 modified system, accounting for the introduction of transperineal biopsy and pre-biopsy multiparametric magnetic resonance imaging (mpMRI). PATIENTS AND METHODS: Between 2002 and 2019, we identified 2431 patients with paired biopsy and RP histopathology from a prospectively recorded and maintained prostate cancer database. Biopsy specimens were graded according to the 2005 GS or ISUP 2014 modified system, according to the year of diagnosis. Multivariable logistic regression analysis was conducted to retrospectively assess the impact of prostate-specific antigen (PSA), PSA density, age, pre-biopsy mpMRI, and biopsy method, on the rate of upgraded disease. The kappa coefficient was used to establish the degree of change in concordance between groups. RESULTS: Overall, 24% of patients had upgraded disease and 8% of patients had downgraded disease when using the modified ISUP 2014 criteria. Agreement in the updated ISUP 2014 cohort was 68%, compared with 55% in the 2005 GS group, which was validated by a kappa coefficient that was good (k = 0.5 ± 0.4) and poor (k = 0.3 ± 0.1), respectively. In multivariable models, a change in grading system independently improved overall disease concordance (P = 0.02), and there were no other co-segregated patient or pathological factors such as PSA, total number of cores, maximum cancer length, biopsy route or the use of mpMRI that impacted this finding. CONCLUSION: The 2014 ISUP modifed system improves overall concordance between biopsy and surgical specimens, and thus allows more accurate prognostication and management in high-grade disease, independent of more extensive prostate sampling and the use of mpMRI.