Patrick O. Richard
Centre Hospitalier Universitaire de Sherbrooke
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Featured researches published by Patrick O. Richard.
European Urology | 2015
Patrick O. Richard; Michael A.S. Jewett; Jaimin R. Bhatt; John R. Kachura; Andrew Evans; Alexandre Zlotta; Thomas Hermanns; Tristan Juvet; Antonio Finelli
BACKGROUND Renal tumor biopsy (RTB) for the characterization of small renal masses (SRMs) has not been widely adopted despite reported safety and accuracy. Without pretreatment biopsy, patients with benign tumors are frequently overtreated. OBJECTIVE To assess the diagnostic rate of RTBs, to determine their concordance with surgical pathology, and to assess their impact on management. DESIGN, SETTING, AND PARTICIPANTS This is a single-institution retrospective study of 529 patients with biopsied solid SRMs ≤4 cm in diameter. RTBs were performed to aid in clinical management. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Diagnostic and concordance rates were presented using proportions. Factors that contributed to a diagnostic biopsy were identified using a multivariable logistic regression. RESULTS AND LIMITATIONS The first biopsy was diagnostic in 90% (n=476) of cases. Of the nondiagnostic biopsies, 24 patients underwent a second biopsy of which 83% were diagnostic. When both were combined, RTBs yielded an overall diagnostic rate of 94%. Following RTB, treatment could have been avoided in at least 26% of cases because the lesion was benign. Tumor size and exophytic location were significantly associated with biopsy outcome. RTB histology and nuclear grade were highly concordant with final pathology (93% and 94%, respectively). Adverse events were low (8.5%) and were all self-limited with the exception of one. Although excellent concordance between RTB and final pathology was observed, only a subset of patients underwent surgery following biopsy. Thus it is possible that some patients were misdiagnosed. CONCLUSIONS RTB of SRMs provided a high rate of diagnostic accuracy, and more than a quarter were benign. Routine RTB for SRMs informs treatment decisions and diminishes unnecessary intervention. Our results support its systematic use and suggest that a change in clinical paradigm should be considered. PATIENT SUMMARY Renal tumor biopsy (RTB) for pretreatment identification of the pathology of small renal masses (SRMs) is safe and reliable and decreases unnecessary treatment. Routine RTB should be considered in all patients with an indeterminate SRM for which treatment is being considered.
British Journal of Cancer | 2014
Thomas Hermanns; Bimal Bhindi; Yanliang Wei; Julie Yu; Aidan P. Noon; Patrick O. Richard; J R Bhatt; A Almatar; Michael A.S. Jewett; Neil Fleshner; Alexandre Zlotta; Arnoud J. Templeton; Girish Kulkarni
Background:An elevated neutrophil-to-lymphocyte ratio (NLR) is associated with poor outcome in various tumours. Its prognostic utility in patients with urothelial carcinoma of the bladder (UCB) undergoing radical cystectomy (RC) is yet to be fully elucidated.Methods:A cohort of patients undergoing RC for UCB in a tertiary referral centre between 1992 and 2012 was analysed. Neutrophil-to-lymphocyte ratio was computed using complete blood counts performed pre-RC, or before neo-adjuvant chemotherapy where applicable. Time-dependent receiver operating characteristic curves were used to determine the optimal cutoff point for predicting recurrence-free survival (RFS), cancer-specific survival (CSS) and overall survival (OS). The predictive ability of NLR was assessed using Kaplan–Meier analyses and multivariable Cox proportional hazards models. The likelihood-ratio test was used to determine whether multivariable models were improved by including NLR.Results:The cohort included 424 patients followed for a median of 58.4 months. An NLR of 3 was determined as the optimal cutoff value. Patients with an NLR⩾3.0 had significantly worse survival outcomes (5y-RFS: 53% vs 64%, log-rank P=0.013; 5y-CSS: 57% vs 75%, log-rank P<0.001; 5y-OS: 43% vs 64%, log-rank P<0.001). After adjusting for disease-specific predictors, an NLR ⩾3.0 was significantly associated with worse RFS (HR=1.49; 95% CI=1.12–2.0, P=0.007), CSS (HR=1.88; 95% CI=1.39–2.54, P<0.001) and OS (average HR=1.67; 95% CI=1.17–2.39, P=0.005). The likelihood-ratio test confirmed that prognostic models were improved by including NLR.Conclusions:Neutrophil-to-lymphocyte ratio is an inexpensive prognostic biomarker for patients undergoing RC for UCB. It offers pre-treatment prognostic value in addition to established prognosticators and may be helpful in guiding treatment decisions.
European Urology | 2016
Jaimin R. Bhatt; Patrick O. Richard; Nicole Kim; Antonio Finelli; Karthikeyan Manickavachagam; Laura Legere; Andrew Evans; York Pei; Jenna Sykes; Kartik S. Jhaveri; Michael A.S. Jewett
BACKGROUND The natural history of renal angiomyolipoma (AML) is unknown. Treatment recommendations are based on smaller case series, with selection bias towards symptomatic patients. OBJECTIVE To define the natural history of renal AML, including growth rates, size, and clinical presentation. DESIGN, SETTING, AND PARTICIPANTS We used a unique radiology data-mining system (Montage; Montage Healthcare Systems, Philadelphia, PA, USA) to retrospectively review the radiology database in an academic health centre between 2002 and 2013 to identify all renal AMLs. Of 2741 patients identified, 447 with 582 AMLs had three or more imaging studies suitable for analysis. INTERVENTION Angioembolisation, surgery, radiofrequency ablation, and mammalian target of rapamycin inhibitors. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The primary end point was the growth rate of untreated AMLs. We used a linear mixed-effects model to determine change in growth rate over time. We evaluated the association among growth rate, size, and patient factors as well as interventions. RESULTS AND LIMITATIONS The majority of untreated AMLs (>92%) had not grown at a median follow-up of 43 mo, with no difference in growth rates between AMLs ≤4 and >4cm. Most AMLs occurred in female participants (80%) and were asymptomatic (91%). Tuberous sclerosis complex (TSC) was confirmed in 3.8% (n=17) and presented at an earlier age. Median size was 1cm but was significantly larger for TSC (5.5cm; p<0.001). Interventions were performed in 5.6% of patients. Limitations of our study include the retrospective design, selection against fat-poor AMLs, and lack of histology. CONCLUSIONS This large, single-institution series on AMLs confirms that lesions >4cm do not require early intervention based on size alone. The vast majority are sporadic, asymptomatic, and initially harmless, with a negligible growth rate. Our findings support a policy of initial active surveillance for all asymptomatic AMLs. PATIENT SUMMARY We evaluated the natural history and growth rates of renal AMLs. We found no difference in growth rates between AMLs >4 and ≤4cm. Initial AS appears to be a safe management option.
The Journal of Urology | 2016
Patrick O. Richard; Michael A.S. Jewett; Jaimin R. Bhatt; Andrew Evans; Narhari Timilsina; Antonio Finelli
PURPOSE Oncocytomas are benign tumors often diagnosed incidentally on imaging. Small case series have suggested that the growth kinetics of oncocytomas are similar to those of malignant renal tumors. Biopsy material may be insufficient to exclude a diagnosis of chromophobe renal cell carcinoma. We evaluated and compared the growth rates of oncocytoma and chromophobe renal cell carcinoma to improve our understanding of their natural history. MATERIALS AND METHODS This was a single center, retrospective study of patients diagnosed with lesions suggestive of oncocytoma or chromophobe renal cell carcinoma between 2003 and 2014. The growth rates were estimated using a mixed effect linear model. Patient and lesion characteristics were tested using a similar model for association with growth rate. RESULTS Of the 95 lesions (oncocytoma 81, chromophobe renal cell carcinoma 14) included in the analysis 98% were diagnosed on biopsy. The annual growth rate was 0.14 cm and 0.38 cm for oncocytoma (median followup 34 months) and chromophobe renal cell carcinoma (median followup 25 months), respectively (p=0.5). Baseline lesion size was significantly associated with growth (p <0.001). The majority of oncocytomas (74%) and chromophobe renal cell carcinomas (67%) followed up to the 3-year mark had grown. Of these, 8 underwent surgery (6 in the chromophobe renal cell carcinoma group). The initial diagnosis was confirmed in all. Overall 5 patients died, all of nonrenal related causes. CONCLUSIONS Although the majority of oncocytic renal neoplasms will grow with time, surveillance appears to remain safe. Patients opting for this strategy should be made aware that a diagnosis of oncocytoma following biopsy is associated with some degree of uncertainty due to the difficulty of differentiating them from other oncocytic renal neoplasms.
British Journal of Cancer | 2016
Bimal Bhindi; Thomas Hermanns; Yanliang Wei; Julie Yu; Patrick O. Richard; Marian S. Wettstein; Arnoud J. Templeton; Kathy Li; Srikala S. Sridhar; Michael A.S. Jewett; Neil E. Fleshner; Alexandre Zlotta; Girish S. Kulkarni
Background:We sought to determine which parsimonious combination of complete blood count (CBC)-based biomarkers most efficiently predicts oncologic outcomes in patients undergoing radical cystectomy (RC) for bladder cancer (BC).Methods:Using our institutional RC database (1992–2012), nine CBC-based markers (including both absolute cell counts and ratios) were evaluated based on pre-treatment measurements. The outcome measures were recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). Time-dependent receiver-operating characteristics curves were used to characterise each biomarker. The CBC-based biomarkers, along with several clinical predictors, were then considered for inclusion in predictive multivariable Cox models based on the Akaike Information Criterion.Results:Our cohort included 418 patients. Neutrophil–lymphocyte ratio (NLR) was the only biomarker satisfying criteria for inclusion into all models, independently predicting RFS (HR per 1-log unit=1.52, 95% CI=1.17–1.98, P=0.002), CSS (HR=1.47, 95% CI=1.20–1.80, P<0.001), and OS (HR=1.56, 95% CI=1.16–2.10, P=0.004). Haemoglobin was also independently predictive of CSS (HR per 1 g/dl=0.91, 95% CI=0.86–0.95, P<0.001) and OS (HR=0.90, 95% CI=0.88–0.93, P<0.001), but not RFS.Conclusions:Among CBC biomarkers studied, NLR was the most efficient marker for predicting RFS, whereas NLR and haemoglobin were most efficient in predicting CSS and OS. NLR and haemoglobin are promising, cost-effective, independent biomarkers for predicting oncologic BC outcomes following RC.Condensed abstract:Various CBC-based biomarkers have separately been shown to be predictive of oncologic outcomes in patients undergoing cystectomy for BC. Our study evaluated these biomarkers, and determined that NLR is the best CBC-based biomarker for predicting RFS, whereas NLR and haemoglobin are most efficient for predicting CSS and OS.
BJUI | 2017
Patrick O. Richard; Michael A.S. Jewett; Simon Tanguay; Olli Saarela; Zhihui Amy Liu; Frédéric Pouliot; Anil Kapoor; Ricardo Rendon; Antonio Finelli
To validate, in a multi‐institution review, the safety, accuracy and reliability of renal tumour biopsy (RTB) and its role in decreasing unnecessary treatment.
Applied Economics | 2012
Stéphane Mussard; Patrick O. Richard
In this article we show that the Gini coefficient is simultaneously decomposable both by sources of income and by populations of income receivers for nonoverlapping income distributions: the so-called first-best Gini multi-decomposition. We show that this multidimensional decomposition is useful for many reasons: (i) it is related to the degree of inequality aversion of the decision maker, (ii) it is especially well suited to study inequalities between poor and nonpoor people, (iii) it enables one to measure the impact of marginal tax reforms on within- and between-group inequalities, respectively.
Physica C-superconductivity and Its Applications | 1999
S. Jandl; Patrick O. Richard; V. Nekvasil; D.I Zhigunov; S. N. Barilo; S.V Shiryaev
Abstract We present an infrared transmission study of Nd2CuO4 Kramers doublets as a function of temperature and polarization. Lifting of the J=9/2, 11/2, 13/2 and 15/2 Kramers doublets degeneracies of the order of few cm−1 is observed which we ascribe to the exchange coupling of the Nd spins to the Cu subsystem. In particular, we show that the doublet splittings data retrace the Nd2CuO4 spin reorientation transitions and imply that the Nd–Cu coupling is strongly anisotropic. This finding supports a model used earlier to interpret the spin reorientation transitions as well as the spin-wave excitation gap data.
Journal of Luminescence | 1998
S. Jandl; P. Dufour; Patrick O. Richard; V. Nekvasil; D.I Zhigunov; S. N. Barilo; S.V Shiryaev
Abstract We have observed infrared active Nd3+ ion crystal-field (CF) excitations as a function of temperature in Nd2CuO4 single crystals. The detected absorption bands allowed to determine 23 excited CF levels of the 4 I term. Using these levels, a set of the parameters of the CF Hamiltonian has been calculated confirming the one determined previously by Raman measurements. CF excitations of Nd3+ ions, in inequivalent sites, have also been detected in as-grown single crystals and associated with two different types of defects.
Applied Economics | 2014
Dorothée Boccanfuso; Marcelin Joanis; Patrick O. Richard; Luc Savard
The economic literature has been investigating the positive relation between public infrastructure spending and the productivity of the private sector since Munnell (1992). We have introduced this relationship into a recursive dynamic computable general equilibrium model of the Quebec economy to investigate various funding schemes to scale up infrastructure spending in the province. We draw our assumptions from Estache et al. (2010) combined with sectoral elasticity parameters. We conduct a comparative analysis where the funding comes from debt alone, and debt with sales tax, income tax and business tax. Our main finding is that the income tax seems to produce the most positive effects and the businesses tax the most negative effects, though differences are small.