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Simple Summary We evaluated renal cancer with varying aggressive appearances on histology, using an emerging form of non-invasive metabolic MRI. This imaging technique assesses the uptake and metabolism of a breakdown product of glucose (pyruvate) labelled with hyperpolarized carbon-13. We show that pyruvate metabolism is dependent on the aggressiveness of an individual tumor and we provide a mechanism for this finding from tissue analysis of molecules influencing pyruvate metabolism, suggesting a role for its membrane transporter. Abstract Differentiating aggressive clear cell renal cell carcinoma (ccRCC) from indolent lesions is challenging using conventional imaging. This work prospectively compared the metabolic imaging phenotype of renal tumors using carbon-13 MRI following injection of hyperpolarized [1-13C]pyruvate (HP-13C-MRI) and validated these findings with histopathology. Nine patients with treatment-naïve renal tumors (6 ccRCCs, 1 liposarcoma, 1 pheochromocytoma, 1 oncocytoma) underwent pre-operative HP-13C-MRI and conventional proton (1H) MRI. Multi-regional tissue samples were collected using patient-specific 3D-printed tumor molds for spatial registration between imaging and molecular analysis. The apparent exchange rate constant (kPL) between 13C-pyruvate and 13C-lactate was calculated. Immunohistochemistry for the pyruvate transporter (MCT1) from 44 multi-regional samples, as well as associations between MCT1 expression and outcome in the TCGA-KIRC dataset, were investigated. Increasing kPL in ccRCC was correlated with increasing overall tumor grade (ρ = 0.92, p = 0.009) and MCT1 expression (r = 0.89, p = 0.016), with similar results acquired from the multi-regional analysis. Conventional 1H-MRI parameters did not discriminate tumor grades. The correlation between MCT1 and ccRCC grade was confirmed within a TCGA dataset (p < 0.001), where MCT1 expression was a predictor of overall and disease-free survival. In conclusion, metabolic imaging using HP-13C-MRI differentiates tumor aggressiveness in ccRCC and correlates with the expression of MCT1, a predictor of survival. HP-13C-MRI may non-invasively characterize metabolic phenotypes within renal cancer.

Objectives: The objective of this review is to provide an evidence-based update on laser surgery for BPH with a focus on comparing Greenlight Photoselective Vaporisation of the Prostate (PVPj to Holmium Laser Enucleation of the Prostate (HoLEP). Methods: We reviewed all HoLEP and PVP papers identified by a Pubmed search using the keywords: laser, prostate, BPH, holmium, HoLEP, PVP and greenlight. The published randomised trials investigating HoLEP and PVP are summarised. As there are no head to head randomised trials comparing HoLEP to PVP, we compare data from individual HoLEP and PVP papers. Data on multiple aspects of laser surgery for BPH are summarised and contrasted for the 2 procedures including: Perioperative management, subjective and objective measures of success, complications, sexual function, prostate volume reduction, durability, and surgery for men with large prostates and those in urinary retention. Results/Conclusions: PVP and HoLEP are very different laser techniques. An important difference between the Green-light laser and holmium and thulium is that its only urological application is prostate ablation. HoLEP is the most advanced laser technique currently available. In contrast to PVP, it has been rigorously evaluated in 8 randomised trials. It is a size independent procedure suitable for any prostate, and highly effective at treating urinary retention. HoLEP has been reported to be durable to periods up to 6 years. More tissue is removed with HoLEP than PVP, and this raises concerns regarding the long term durability of PVP for which there is no comparable data. The increase in HoLEP expertise world-wide and the development of lasers that are faster at ablating tissue and have other urological uses (eg thulium) may threaten the longevity of Greenlight PVP. Objetivo: El objetivo de ésta revisión es ofrecer una puesta al día basada en la evidencia sobre cirugía láser para el tratamiento de la HBP, enfocada a la comparación entre vaporización fotoselectiva con láser verde (PVP) y la enucleación prostática con láser de Holmio(HoLEP). Métodos: Revisamos todos los artículos sobre HoLEP y PVP identificados en una búsqueda bibliográfica en PubMed utilizando los términos: láser, próstata, HBP, Holmio, HoLEP, PVP, y luz verde. Como no existen ensayos clínicos aleatorizados comparando directamente HoLEP y PVP comparamos los datos de artículos individuales de cada técnica. Se resumen y contrastan los datos de múltiples aspectos de la cirugía láser de la HBP mediante ambos procedimientos incluyendo: manejo perioperatorio, medidas objetivas y subjetivas de éxito, complicaciones, función sexual, reducción del volumen prostático, durabilidad y cirugía en varones con próstatas grandes y pacientes con retención urinaria. Resultados/Conclusiones: La PVP y la HoLEP son técnicas láser muy diferentes. Una diferencia importante entre el láser de luz verde y los de Holmio o Tulio es que su única aplicación es la ablación prostática. La técnica de enucleación con láser de Holmio es la técnica láser más avanzada disponible actualmente. En contraste con la fotovaporización ha sido rigurosamente evaluada en ocho ensayos clínicos. Es un procedimiento independiente del tamaño prostático, válido para cualquier próstata, altamente eficaz en el tratamiento de la retención urinaria. Se ha comunicado que la enucleación prostática con láser de Holmio es duradera hasta seis años. Se quita más tejido con la HOLEP y con la PVP y esto suscita una preocupación en cuanto a la duración a largo plazo del resultado de la PVP, de la que no existen datos comparables. El aumento de la experiencia con HoLEP en todo el mundo y el desarrollo de láseres más rápidos en la ablación de tejidos y con otros usos urológicos (Ej tulio) puede amenazar la supervivencia de la PVP con láser de luz verde.

Objectives: The objective of this review is to provide an evidence-based update on laser surgery for BPH with a focus on comparing Greenlight Photoselective Vaporisation of the Prostate (PVPj to Holmium Laser Enucleation of the Prostate (HoLEP). Methods: We reviewed all HoLEP and PVP papers identified by a Pubmed search using the keywords: laser, prostate, BPH, holmium, HoLEP, PVP and greenlight. The published randomised trials investigating HoLEP and PVP are summarised. As there are no head to head randomised trials comparing HoLEP to PVP, we compare data from individual HoLEP and PVP papers. Data on multiple aspects of laser surgery for BPH are summarised and contrasted for the 2 procedures including: Perioperative management, subjective and objective measures of success, complications, sexual function, prostate volume reduction, durability, and surgery for men with large prostates and those in urinary retention. Results/Conclusions: PVP and HoLEP are very different laser techniques. An important difference between the Green-light laser and holmium and thulium is that its only urological application is prostate ablation. HoLEP is the most advanced laser technique currently available. In contrast to PVP, it has been rigorously evaluated in 8 randomised trials. It is a size independent procedure suitable for any prostate, and highly effective at treating urinary retention. HoLEP has been reported to be durable to periods up to 6 years. More tissue is removed with HoLEP than PVP, and this raises concerns regarding the long term durability of PVP for which there is no comparable data. The increase in HoLEP expertise world-wide and the development of lasers that are faster at ablating tissue and have other urological uses (eg thulium) may threaten the longevity of Greenlight PVP.

Background: Cell-free tumor-derived DNA (ctDNA) allows non-invasive monitoring of cancers, but its utility in renal cell cancer (RCC) has not been established. Methods: Here, a combination of untargeted and targeted sequencing methods, applied to two independent cohorts of patients (n = 91) with various renal tumor subtypes, were used to determine ctDNA content in plasma and urine. Results: Our data revealed lower plasma ctDNA levels in RCC relative to other cancers of similar size and stage, with untargeted detection in 27.5% of patients from both cohorts. A sensitive personalized approach, applied to plasma and urine from select patients (n = 22) improved detection to ~ 50%, including in patients with early-stage disease and even benign lesions. Detection in plasma, but not urine, was more frequent amongst patients with larger tumors and in those patients with venous tumor thrombus. With data from one extensively characterized patient, we observed that plasma and, for the first time, urine ctDNA may better represent tumor heterogeneity than a single tissue biopsy. Furthermore, in a subset of patients (n = 16), longitudinal sampling revealed that ctDNA can track disease course and may pre-empt radiological identification of minimal residual disease or disease progression on systemic therapy. Additional datasets will be required to validate these findings. Conclusions: These data highlight RCC as a ctDNA-low malignancy. The biological reasons for this are yet to be determined. Nonetheless, our findings indicate potential clinical utility in the management of patients with renal tumors, provided improvement in isolation and detection approaches.

BACKGROUND: Cell-free tumor-derived DNA (ctDNA) allows non-invasive monitoring of cancers, but its utility in renal cell cancer (RCC) has not been established. METHODS: Here, a combination of untargeted and targeted sequencing methods, applied to two independent cohorts of patients (n = 91) with various renal tumor subtypes, were used to determine ctDNA content in plasma and urine. RESULTS: Our data revealed lower plasma ctDNA levels in RCC relative to other cancers of similar size and stage, with untargeted detection in 27.5% of patients from both cohorts. A sensitive personalized approach, applied to plasma and urine from select patients (n = 22) improved detection to ~ 50%, including in patients with early-stage disease and even benign lesions. Detection in plasma, but not urine, was more frequent amongst patients with larger tumors and in those patients with venous tumor thrombus. With data from one extensively characterized patient, we observed that plasma and, for the first time, urine ctDNA may better represent tumor heterogeneity than a single tissue biopsy. Furthermore, in a subset of patients (n = 16), longitudinal sampling revealed that ctDNA can track disease course and may pre-empt radiological identification of minimal residual disease or disease progression on systemic therapy. Additional datasets will be required to validate these findings. CONCLUSIONS: These data highlight RCC as a ctDNA-low malignancy. The biological reasons for this are yet to be determined. Nonetheless, our findings indicate potential clinical utility in the management of patients with renal tumors, provided improvement in isolation and detection approaches.

Background: Cell-free tumor-derived DNA (ctDNA) allows non-invasive monitoring of cancers, but its utility in renal cell cancer (RCC) has not been established. Methods: Here, a combination of untargeted and targeted sequencing methods, applied to two independent cohorts of patients (n = 91) with various renal tumor subtypes, were used to determine ctDNA content in plasma and urine. Results: Our data revealed lower plasma ctDNA levels in RCC relative to other cancers of similar size and stage, with untargeted detection in 27.5% of patients from both cohorts. A sensitive personalized approach, applied to plasma and urine from select patients (n = 22) improved detection to ~ 50%, including in patients with early-stage disease and even benign lesions. Detection in plasma, but not urine, was more frequent amongst patients with larger tumors and in those patients with venous tumor thrombus. With data from one extensively characterized patient, we observed that plasma and, for the first time, urine ctDNA may better represent tumor heterogeneity than a single tissue biopsy. Furthermore, in a subset of patients (n = 16), longitudinal sampling revealed that ctDNA can track disease course and may pre-empt radiological identification of minimal residual disease or disease progression on systemic therapy. Additional datasets will be required to validate these findings. Conclusions: These data highlight RCC as a ctDNA-low malignancy. The biological reasons for this are yet to be determined. Nonetheless, our findings indicate potential clinical utility in the management of patients with renal tumors, provided improvement in isolation and detection approaches.

BACKGROUND:Cell-free tumor-derived DNA (ctDNA) allows non-invasive monitoring of cancers, but its utility in renal cell cancer (RCC) has not been established. METHODS:Here, a combination of untargeted and targeted sequencing methods, applied to two independent cohorts of patients (n = 91) with various renal tumor subtypes, were used to determine ctDNA content in plasma and urine. RESULTS:Our data revealed lower plasma ctDNA levels in RCC relative to other cancers of similar size and stage, with untargeted detection in 27.5% of patients from both cohorts. A sensitive personalized approach, applied to plasma and urine from select patients (n = 22) improved detection to ~ 50%, including in patients with early-stage disease and even benign lesions. Detection in plasma, but not urine, was more frequent amongst patients with larger tumors and in those patients with venous tumor thrombus. With data from one extensively characterized patient, we observed that plasma and, for the first time, urine ctDNA may better represent tumor heterogeneity than a single tissue biopsy. Furthermore, in a subset of patients (n = 16), longitudinal sampling revealed that ctDNA can track disease course and may pre-empt radiological identification of minimal residual disease or disease progression on systemic therapy. Additional datasets will be required to validate these findings. CONCLUSIONS:These data highlight RCC as a ctDNA-low malignancy. The biological reasons for this are yet to be determined. Nonetheless, our findings indicate potential clinical utility in the management of patients with renal tumors, provided improvement in isolation and detection approaches.