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The current prostate cancer (PCa) screen test, prostate-specific antigen (PSA), has a high sensitivity for PCa but low specificity for high-risk, clinically significant PCa (csPCa), resulting in overdiagnosis and overtreatment of non-csPCa. Early identification of csPCa while avoiding unnecessary biopsies in men with non-csPCa is challenging. We built an optimized machine learning platform (ClarityDX) and showed its utility in generating models predicting csPCa. Integrating the ClarityDX platform with blood-based biomarkers for clinically significant PCa and clinical biomarker data from a 3448-patient cohort, we developed a test to stratify patients' risk of csPCa; called ClarityDX Prostate. When predicting high risk cancer in the validation cohort, ClarityDX Prostate showed 95% sensitivity, 35% specificity, 54% positive predictive value, and 91% negative predictive value, at a ≥ 25% threshold. Using ClarityDX Prostate at this threshold could avoid up to 35% of unnecessary prostate biopsies. ClarityDX Prostate showed higher accuracy for predicting the risk of csPCa than PSA alone and the tested model-based risk calculators. Using this test as a reflex test in men with elevated PSA levels may help patients and their healthcare providers decide if a prostate biopsy is necessary.
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OBJECTIVES: To evaluate the International Society of Urological Pathology (ISUP) 5-tier grade grouping (GG) system of prostate cancers as well as previously proposed optimizations. PATIENTS AND METHODS: The PROCURE biobank is a prospective cohort study of patients with localized prostate cancer who underwent radical prostatectomy in Quebec province between 2005 and 2013. Surgical specimens were graded by experienced genitourinary pathologists using 2019 ISUP criteria. Follow-up was conducted until November 2021. The current 5-tier and a proposed 6-tier GG system were evaluated, the latter having two changes: 1) Gleason 3 + 4 and 4 + 3 tumors with minor/tertiary Gleason 5 patterns were upgraded to GG 3 and 4, respectively; and 2) patients in GG5 were separated based on primary Gleason pattern (4 or 5). Cox proportional hazards models and Harrell's concordance (C) indices were used for statistical analyses. RESULTS: 2003 patients were included (median follow-up: 8.7 years). The current 5-tier GG system predicted time to recurrence (hazard ratio [HR] 2.12, 95% confidence interval [95%CI] 1.99-2.25, C 0.717), androgen-deprivation therapy (HR 2.58, 95%CI 2.38-2.80, C 0.790), metastasis (HR 2.48, 95%CI 2.17-2.83, C 0.806), castration-resistant prostate cancer (HR 2.67, 95%CI 2.28-3.13, C 0.829), and cancer-specific mortality (HR 2.80, 95%CI 2.27-3.44, C 0.835). Goodness-of-fit further improved with the proposed 6-tier GG system, with Harrell's C of 0.733, 0.807, 0.827, 0.853, and 0.853, respectively. CONCLUSIONS: The 5-tier GG system predicted short- and long-term outcomes for patients with localized prostate cancer, and the proposed 6-tier GG system further improved its accuracy.
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Clasificación del Tumor , Prostatectomía , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/patología , Persona de Mediana Edad , Anciano , Estudios Prospectivos , Recurrencia Local de Neoplasia/patología , Factores de TiempoRESUMEN
BACKGROUND: Prostate cancer (PCa) patients receiving radiotherapy may be predisposed to secondary malignancies. This study aimed to determine the association between PCa treatments, including radical prostatectomy (RP), external beam radiation therapy (EBRT), brachytherapy (BT) and androgen deprivation therapy (ADT); and secondary bladder and colorectal cancer. METHODS: A cohort study was constructed using Quebec administrative databases (Med-Echo and RAMQ). Included men were diagnosed and treated for PCa between 2000 and 2016. Patients with bladder or colorectal cancer prior to PCa were excluded. Follow-up ended at the earliest of the following: incidence of bladder or colorectal cancer, death, or December 31, 2016. EBRT, BT, EBRT+ADT, RP + ADT or ADT only were compared individually to RP. The incidence of secondary bladder and colorectal cancer were computed. Inverse probability of treatment weighting (IPTW) based on a propensity score was used to control for potential confounding. IPTW-Cox proportional hazards models were used. RESULTS: A significant association was found between secondary bladder cancer and EBRT (HR: 1.84, 95%CI: 1.60;2.13), and also EBRT+ADT (HR: 2.08, 95%CI: 1.67;2.56), but not with BT (HR: 1.36, 95%CI: 0.68;2.74). Secondary colorectal cancer was significantly associated to either EBRT (HR: 1.36, 95%CI: 1.21;1.53); or BT (HR: 2.46, 95%CI: 1.71;3.54). The association between ADT alone and both secondary cancers was also significant (HR: 1.98, 95%CI: 1.69;2.31 and HR: 1.69, 95%CI: 1.49;1.92, respectively). CONCLUSIONS: Compared to PCa patients undergoing RP, the secondary bladder cancer was associated with EBRT, ADT, alone or in combination. The secondary colorectal cancer was also associated with receiving either EBRT, BT or ADT.
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Neoplasias Colorrectales , Neoplasias Primarias Secundarias , Neoplasias de la Próstata , Neoplasias de la Vejiga Urinaria , Masculino , Humanos , Vejiga Urinaria , Neoplasias de la Próstata/epidemiología , Neoplasias de la Próstata/terapia , Antagonistas de Andrógenos/efectos adversos , Estudios de Cohortes , Neoplasias Primarias Secundarias/epidemiología , Neoplasias Primarias Secundarias/etiología , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/terapiaRESUMEN
BACKGROUND: Studies have suggested a positive association between bladder cancer (BC) outcome and comedication use, including nonsteroidal anti-inflammatory drugs (NSAID), metformin, and prednisone use. To validate these associations, we evaluated whether these medications were associated with clinical outcome in a Canadian cohort of BC patients. METHODS: This is a retrospective cohort study on BC patients undergoing radical cystectomy (RC) in Québec province in 2000-2015, as registered in the provincial health administration databases. Medication use was considered chronic when prescribed for ≥ 1 year. Overall (OS), disease-specific (DSS) and recurrence-free (RFS) survival were compared using multivariable Cox proportional hazards models. Covariates included age, Charlson's comorbidity index, region of residence, year of RC, distance to hospital, hospital type, hospital and surgeon annual RC volume, neoadjuvant chemotherapy use, and type of bladder diversion, as well as mutual adjustment for concomitant comedication use (statins, NSAIDs, metformin, and prednisone). RESULTS: Of 3742 patients included, 293, 420, and 1503 patients chronically used prednisone, metformin, and NSAIDs before surgery, respectively. In multivariable analyses, preoperative prednisone use was associated with improved OS (HR 0.67, 95%CI 0.55-0.82), DSS (HR 0.58, 95%CI 0.45-0.76), and RFS (HR 0.61, 95%CI 0.47-0.78). Patients who chronically used metformin preoperatively had a worse OS (HR 1.29, 95%CI 1.07-1.55), DSS (HR 1.38, 95%CI 1.10-1.72), and RFS (HR 1.41, 95%CI 1.13-1.74). Preoperative, chronic NSAID use was not significantly associated with all clinical outcomes, with adjusted HRs for OS, DSS, and RFS of 1.10 (95%CI 0.95-1.27), 1.24 (95%CI 1.03-1.48), and 1.22 (95%CI 1.03-1.45), respectively. Directionality of findings was similar when stratifying by comedication use in the year following surgery. Results were similar after propensity-score matching too. CONCLUSIONS: In our Canadian cohort of BC undergoing RC, chronic prednisone use was associated with improved clinical outcomes, while metformin and NSAID were not.
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Metformina , Neoplasias de la Vejiga Urinaria , Humanos , Vejiga Urinaria , Cistectomía/métodos , Quebec/epidemiología , Prednisona/uso terapéutico , Metformina/uso terapéutico , Estudios Retrospectivos , Supervivencia sin Enfermedad , Canadá , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/cirugía , Antiinflamatorios no Esteroideos/uso terapéutico , Resultado del TratamientoRESUMEN
BACKGROUND: There is an unmet clinical need for minimally invasive diagnostic tests to improve the detection of grade group (GG) ≥3 prostate cancer relative to prostate antigen-specific risk calculators. We determined the accuracy of the blood-based extracellular vesicle (EV) biomarker assay (EV Fingerprint test) at the point of a prostate biopsy decision to predict GG ≥3 from GG ≤2 and avoid unnecessary biopsies. METHODS: This study analyzed 415 men referred to urology clinics and scheduled for a prostate biopsy, were recruited to the APCaRI 01 prospective cohort study. The EV machine learning analysis platform was used to generate predictive EV models from microflow data. Logistic regression was then used to analyze the combined EV models and patient clinical data and generate the patients' risk score for GG ≥3 prostate cancer. RESULTS: The EV-Fingerprint test was evaluated using the area under the curve (AUC) in discrimination of GG ≥3 from GG ≤2 and benign disease on initial biopsy. EV-Fingerprint identified GG ≥3 cancer patients with high accuracy (0.81 AUC) at 95% sensitivity and 97% negative predictive value. Using a 7.85% probability cutoff, 95% of men with GG ≥3 would have been recommended a biopsy while avoiding 144 unnecessary biopsies (35%) and missing four GG ≥3 cancers (5%). Conversely, a 5% cutoff would have avoided 31 unnecessary biopsies (7%), missing no GG ≥3 cancers (0%). CONCLUSIONS: EV-Fingerprint accurately predicted GG ≥3 prostate cancer and would have significantly reduced unnecessary prostate biopsies.
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Vesículas Extracelulares , Neoplasias de la Próstata , Masculino , Humanos , Próstata/patología , Antígeno Prostático Específico , Estudios Prospectivos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/patología , Biopsia , Vesículas Extracelulares/patologíaRESUMEN
Background: Orally administrated agents play a key role in the management of prostate cancer, providing a convenient and cost-effective treatment option for patients. However, they are also associated with adherence issues which can compromise therapeutic outcomes. This scoping review identifies and summarizes data on adherence to oral hormonal therapy in advanced prostate cancer and discusses associated factors and strategies for improving adherence. Methods: PubMed (inception to 27 January 2022) and conference databases (2020-2021) were searched to identify English language reports of real-world and clinical trial data on adherence to oral hormonal therapy in prostate cancer using the key search terms 'prostate cancer' AND 'adherence' AND 'oral therapy' OR respective aliases. Results: Most adherence outcome data were based on the use of androgen receptor pathway inhibitors in metastatic castration-resistant prostate cancer (mCRPC). Self-reported and observer-reported adherence data were used. The most common observer-reported measure, medication possession ratio, showed that the vast majority of patients were in possession of their medication, although proportion of days covered and persistence rates were considerably lower, raising the question whether patients were consistently receiving their treatment. Study follow-up for adherence was generally around 6 months up to 1 year. Studies also indicate that persistence may drop further with longer follow-up, especially in the non-mCRPC setting, which may be a concern when years of therapy are required. Conclusions: Oral hormonal therapy plays an important role in the treatment of advanced prostate cancer. Data on adherence to oral hormonal therapies in prostate cancer were generally of low quality, with high heterogeneity and inconsistent reporting across studies. Short study follow-up for adherence and focus on medication possession rates may further limit relevance of available data, especially in settings that require long-term treatment. Additional research is required to comprehensively assess adherence.
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The androgen receptor (AR) plays a crucial role in the development and homeostasis of the prostate and is a key therapeutic target in prostate cancer (PCa). The gold standard therapy for advanced PCa is androgen deprivation therapy (ADT), which targets androgen production and AR signaling. However, resistance to ADT develops via AR-dependent and AR-independent mechanisms. As reports on AR expression patterns in PCa have been conflicting, we performed cell-by-cell AR quantification by immunohistochemistry in the benign and malignant prostate to monitor changes with disease development, progression, and hormonal treatment. Prostates from radical prostatectomy (RP) cases, both hormone-naïve and hormone-treated, prostate tissues from patients on palliative ADT, and bone metastases were included. In the normal prostate, AR is expressed in >99% of luminal cells, 51% of basal cells, and 61% of fibroblasts. An increase in the percentage of AR negative (%AR-) cancer cells along with a gradual loss of fibroblastic AR were observed with increasing Gleason grade and hormonal treatment. This was accompanied by a parallel increase in staining intensity of AR positive (AR+) cells under ADT. Staining AR with N- and C-terminal antibodies yielded similar results. The combination of %AR- cancer cells, %AR- fibroblasts, and AR intensity score led to the definition of an AR index, which was predictive of biochemical recurrence in the RP cohort and further stratified patients of intermediate risk. Lastly, androgen receptor variant 7 (ARV7)+ cells and AR- cells expressing neuroendocrine and stem markers were interspersed among a majority of AR+ cells in ADT cases. Altogether, the comprehensive quantification of AR expression in the prostate reveals concomitant changes in tumor cell subtypes and fibroblasts, emphasizing the significance of AR- cells with disease progression and palliative ADT.
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Neoplasias de la Próstata , Receptores Androgénicos , Masculino , Humanos , Receptores Androgénicos/metabolismo , Receptores Androgénicos/uso terapéutico , Próstata/metabolismo , Próstata/patología , Neoplasias de la Próstata/patología , Andrógenos/metabolismo , Andrógenos/uso terapéutico , Antagonistas de Andrógenos/uso terapéuticoRESUMEN
BACKGROUND: Distinguishing between true indolent and potentially life-threatening prostate cancer is challenging in tumours displaying clinicopathologic features associated with low or intermediate risk of relapse. Several somatic DNA copy number alterations (CNAs) have been identified as potential prognostic biomarkers, but the standard cytogenetic method to assess them has a limited multiplexing capability. METHODS: Multiplex ligation-dependent probe amplification (MLPA) targeting 14 genes was optimised to survey 448 tumours of patients with low or intermediate risk (Grade Group 1-3, Gleason score ≤7) who underwent radical prostatectomy. A 6-gene CNA classifier was developed using random survival forest and Cox proportional hazard modelling to predict biochemical recurrence. RESULTS: The classifier score was significantly associated with biochemical recurrence after adjusting for standard clinicopathologic variables and the known prognostic index CAPRA-S score with a hazard ratio of 2.17 and 1.80, respectively (n = 406, P < 0.01). The prognostic value of this classifier was externally validated in published CNA data from three radical prostatectomy cohorts and one radiation therapy pre-treatment biopsy cohort. CONCLUSION: The 6-gene CNA classifier generated by a single MLPA assay compatible with the small quantities of DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue specimens has the potential to improve the clinical management of patients with low or intermediate risk disease.
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Variaciones en el Número de Copia de ADN , Neoplasias de la Próstata , Masculino , Humanos , Pronóstico , Biomarcadores de Tumor/genética , Recurrencia Local de Neoplasia/genética , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/cirugía , Neoplasias de la Próstata/patología , Prostatectomía , Medición de RiesgoRESUMEN
BACKGROUND: Controversy exists regarding the risk of cardiovascular disease (CVD) associated with androgen deprivation therapy (ADT) in patients with prostate cancer. We sought to evaluate the association between gonadotropin-releasing hormone (GnRH) agonists versus GnRH antagonist and the risk of CVD in patients with prostate cancer with or without prior CVD. PATIENTS AND METHODS: Using administrative databases from Quebec, Canada, we identified first-time GnRH agonists and antagonist (degarelix) users between January 2012 and June 2016. Follow-up ended at the earliest of the following: first CVD event (myocardial infarction [MI], stroke, ischemic heart disease [IHD], arrhythmia, and heart failure [HF]); switch of GnRH group; death; or December 31, 2016. Inverse probability of treatment weighting (IPTW) based on the propensity score was used to control for potential confounding. IPTW-Cox proportional hazards model accounting for competing risks was used to evaluate the association of interest. RESULTS: Among 10,785 patients identified, 10,201 and 584 were on GnRH agonists and antagonist, respectively. Median age was 75 years (interquartile range, 69-81 years) for both groups. A total of 4,152 (40.7%) men in the GnRH agonists group and 281 (48.1%) men in the GnRH antagonist group had CVD in the 3-year period prior to ADT initiation. Risk of HF was decreased in the antagonist group compared with the GnRH agonist group among patients with prior CVD (hazard ratio [HR], 0.46; 95% CI, 0.26-0.79). Risk of IHD was decreased in the antagonist group in patients without prior CVD (HR, 0.26; 95% CI, 0.11-0.65). Use of antagonist was associated with an increased risk of arrhythmia among patients with no prior CVD (HR, 2.34; 95% CI, 1.63-3.36). CONCLUSIONS: Compared with GnRH agonists, the GnRH antagonist was found to be associated with a decreased risk of HF, specifically among patients with prior CVD. Among those with no prior CVD, the GnRH antagonist was associated with a decreased risk of IHD but an increased risk of arrhythmia.
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Enfermedades Cardiovasculares , Neoplasias de la Próstata , Anciano , Humanos , Masculino , Antagonistas de Andrógenos/efectos adversos , Andrógenos , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Hormona Liberadora de Gonadotropina , Factores de Riesgo de Enfermedad Cardiaca , Neoplasias de la Próstata/complicaciones , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/epidemiología , Factores de Riesgo , Femenino , Anciano de 80 o más AñosRESUMEN
The androgen inactivating UGT2B28 pathway emerges as a predictor of progression in prostate cancer (PCa). However, the clinical significance of UGT2B28 tumoral expression and its contribution to PCa progression remain unclear. Using the Canadian Prostate Cancer Biomarker Network biobank (CPCBN; n = 1512), we analyzed UGT2B28 tumor expression in relation to clinical outcomes in men with localized PCa. UGT2B28 was overexpressed in tumors compared to paired normal adjacent prostatic tissue and was associated with inferior outcomes. Functional analyses indicated that UGT2B28 promoted cell proliferation, and its expression was regulated by the androgen receptor (AR)/ARv7. Mechanistically, UGT2B28 was shown to be a protein partner of the endocytic adaptor protein huntingtin-interacting protein 1 (HIP1), increasing its stability and priming AR/epidermal growth factor receptor (EGFR) pathways, leading to ERK1/2 activation triggering cell proliferation and epithelial-to-mesenchymal transition (EMT). HIP1 knockdown in UGT2B28 positive cells, and dual pharmacological targeting of AR and EGFR pathways, abolished cell proliferative advantages conferred by UGT2B28. In conclusion, UGT2B28 is a prognosticator of progression in localized PCa, regulates both AR and EGFR oncogenic signaling pathways via HIP1, and therefore can be therapeutically targeted by using combination of existing AR/EGFR inhibitors.
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Neoplasias de la Próstata , Receptores Androgénicos , Masculino , Humanos , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Próstata/patología , Receptores ErbB/metabolismo , Línea Celular Tumoral , Canadá , Neoplasias de la Próstata/patología , Proteínas de Unión al ADN/genéticaRESUMEN
PURPOSE: Adrenal 11-oxygenated androgens may support cancer progression in men with prostate cancer owing to their abundance and androgenic potential. We hypothesized that preoperative circulating levels of 11-oxygenated androgens influence clinical outcomes in men with newly diagnosed localized prostate cancer. MATERIALS AND METHODS: We studied 1,793 treatment-naïve patients and 155 patients who received preoperative treatment with 5α-reductase inhibitors in the prospective PROCURE cohort, for which preoperative plasma samples were obtained prior to radical prostatectomy. Adrenal 11-oxygenated precursors, potent 11-oxygenated androgens and their metabolites (n=7), were quantified using liquid chromatography-tandem mass spectrometry. Circulating levels were evaluated in relation to prognostic factors, disease-free survival, and metastasis-free survival using multivariable Cox proportional hazards models. RESULTS: At a median follow-up of 93.8 months after surgery, 583 patients experienced biochemical recurrence, 104 developed metastatic disease, and 168 deceased. Higher levels of 11-hydroxytestosterone and 11-ketotestosterone were observed in men with PSA >20 ng/mL and positive nodal status (P < .05). In multivariable analyses, no significant association between 11-oxygenated androgens and disease-free survival was observed. Adrenal 11ß-hydroxyandrostenedione, the predominant androgenic 11-ketotestosterone, and its metabolite 11-ketoandrosterone, modeled as quartiles, were associated with metastasis-free survival (P = .06, P = .03, and P = .008, respectively). Significant accumulation of 11-oxygenated androgen precursors and bioactive androgens, but reduced metabolite levels, was observed in patients on 5α-reductase inhibitors (P < .001). CONCLUSIONS: Preoperative circulating 11-oxygenated androgen levels are associated with metastasis-free survival in men with localized prostate cancer undergoing radical prostatectomy and are affected by 5α-reductase inhibitor treatment.
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Andrógenos , Neoplasias de la Próstata , Masculino , Humanos , Andrógenos/uso terapéutico , Estudios Prospectivos , Neoplasias de la Próstata/tratamiento farmacológico , Espectrometría de Masas , Oxidorreductasas/uso terapéutico , Prostatectomía , Antígeno Prostático EspecíficoRESUMEN
BACKGROUND: Naturally occurring germline gene deletions (KO) represent a unique setting to interrogate gene functions. Complete deletions and differential expression of the human glycosyltransferase UGT2B17 and UGT2B28 genes are linked to prostate cancer (PCa) risk and progression, leukaemia, autoimmune and other diseases. METHODS: The systemic metabolic consequences of UGT deficiencies were examined using untargeted and targeted mass spectrometry-based metabolomics profiling of carefully matched, treatment-naive PCa cases. RESULTS: Each UGT KO differentially affected over 5% of the 1545 measured metabolites, with divergent metabolic perturbations influencing the same pathways. Several of the perturbed metabolites are known to promote PCa growth, invasion and metastasis, including steroids, ceramides and kynurenine. In UGT2B17 KO, reduced levels of inactive steroid-glucuronides were compensated by sulfated derivatives that constitute circulating steroid reservoirs. UGT2B28 KO presented remarkably lower levels of oxylipins paralleled by reduced inflammatory mediators, but higher ceramides unveiled as substrates of the enzyme in PCa cells. CONCLUSION: The distinctive and broad metabolic rewiring caused by UGT KO reinforces the need to examine their unique and divergent functions in PCa biology.
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Glucuronosiltransferasa , Neoplasias de la Próstata , Humanos , Masculino , Técnicas de Inactivación de Genes , Glucurónidos , Fenotipo , Neoplasias de la Próstata/patología , Esteroides , Glucuronosiltransferasa/genéticaRESUMEN
Approximately 4%-10% of patients with renal cell carcinoma (RCC) have tumoral vascular invasion with resultant thrombi in the renal vein and in the inferior vena cava (IVC). The authors describe an interesting case of IVC tumor thrombus that migrated to the right cardiac chambers during RCC resection. The diagnosis was made by intraoperative transesophageal echocardiography (TEE), which revealed the presence of a free-floating thrombus between the right atrium (RA) and right ventricle (RV). The patient required an urgent sternotomy with cardiopulmonary bypass (CPB) for atrial thrombus removal prior to the completion of the nephrectomy. The patient made a full recovery and was discharged to a rehabilitation facility. These findings illustrate the importance of intraoperative TEE monitoring during nephrectomy and IVC thrombectomy. In this case, TEE allowed for the diagnosis of an unexpected complication necessitating prompt cardiac surgical management.
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BACKGROUND: The introduction of novel hormonal agents (NHAs) such as abiraterone acetate (ABI) and enzalutamide (ENZ) for metastatic castration-resistant prostate cancer (mCRPC) was an important milestone given their survival benefits, tolerability, and ease of administration relative to taxane chemotherapies. This descriptive study sought to describe the utilization trends of ABI and ENZ in patients with mCRPC in the early years after their approval in the province of Quebec in Canada. METHODS: A retrospective population-based cohort was extracted from Quebec public healthcare administrative databases. The cohort included first-time users of NHAs (ABI or ENZ) from 2011 to 2016. The primary analyses aimed to describe the overall temporal trends (2011-2016) of NHA initiators by chemotherapy status (chemotherapy-naïve versus post-chemotherapy), and prescribing specialty (medical oncology versus urology versus others). RESULTS: The cohort comprised 2183 patients, with 1562 (72%) in the chemotherapy-naïve group and 621 (28%) in the post-chemotherapy group. While the majority of patients were post-chemotherapy NHA initiators in 2012, this proportion decreased over time and accounted for only 13% of NHA initiators by the end of 2016. Medical oncologists were the most frequent prescribers of NHAs (upwards of 60%) throughout 2012 but fell to 45% by the end of 2016. Conversely, the proportion of prescriptions by urologists increased from 22% in 2012 to 42% in 2016. CONCLUSION: Over time, there was an increasing proportion of (1) patients who initiated NHAs without prior chemotherapy treatment, (2) NHA prescribing by urologists, and (3) ENZ users. Taken together, this implies that the introduction of NHAs has altered the management of mCRPC and urologists quickly adopted NHAs into their practice.