Understanding Treatment Patterns and Outcomes among Patients with De Novo Unresectable Locally Advanced or Metastatic Urothelial Cancer: A Population-Level Retrospective Analysis from Alberta, Canada.

Despite a high disease burden, real-world data on treatment patterns in patients with unresectable locally advanced or metastatic urothelial carcinoma (la/mUC) in Canada are limited. This retrospective, longitudinal cohort study describes treatment patterns and survival in a population of patients with de novo unresectable la/mUC from Alberta, Canada, diagnosed between 1 January 2015 and 31 December 2019, followed until mid-2020. The outcomes of interest were systemic therapy treatment patterns and overall survival (OS). Of 206 patients, most (65.0%, n = 134) did not receive any systemic therapies. Of 72 patients (35.0%) who received first-line systemic therapy, the median duration of treatment was 2.8 months (IQR 3.3). Thirty-five patients (48.6% of those who received first-line therapy) received subsequent second-line therapy, for a median of 3.0 months (IQR 3.3). In all patients (n = 206), the median OS from diagnosis was 5.3 months (95% CI, 4.5-7.0). In patients who received treatment, the median OS from the initiation of first-line and second-line systemic therapy was 9.1 (6.4-11.6) and 4.6 months (3.9-19.2), respectively. The majority of patients did not receive first-line systemic therapy, and, in those who did, survival outcomes were poor. This study highlights the significant unmet need for safe and efficacious therapies for patients with la/mUC in Canada.

Beneficial effects of atorvastatin on lung structural remodeling and function in ischemic heart failure.

BACKGROUND: Studies have suggested some benefit of 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors in congestive heart failure (CHF), although the mechanisms remain uncertain. We hypothesized that statins could improve pulmonary hypertension and right ventricular function in ischemic CHF by reducing lung remodeling. METHODS AND RESULTS: Two weeks after myocardial infarct, rats received atorvastatin (n = 23) or no treatment (n = 23) for 3 weeks and were compared with a sham group (n = 16). Infarct size was similar by echocardiography and pathologic evaluations. Atorvastatin greatly reduced pulmonary hypertension and right ventricular hypertrophy: right ventricular systolic pressure 42 +/- 5 vs. 28 +/- 2 mm Hg (P < .01). Atorvastatin did not reduce left ventricular fibrosis and had minimal effects on left ventricular function. Right ventricular myocardial performance index was markedly improved by therapy (P < .01). CHF caused a restrictive lung syndrome with a downward shift of the respiratory pressure-volume loop, increased dry lung weight, and interstitial fibrosis that were greatly improved by atorvastatin. Reduced lung nitric oxide synthase expression was normalized by treatment. Atorvastatin also reduced isolated lung myofibroblasts proliferation after transforming growth factor-beta stimulation (-36 +/- 6%, P < 0.01). CONCLUSIONS: 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibition reduces lung remodeling and dysfunction associated with heart failure with prevention of right ventricular hypertrophy and pulmonary hypertension.

Change in pharmacological effect of endothelin receptor antagonists in rats with pulmonary hypertension: role of ETB-receptor expression levels.

BACKGROUND AND PURPOSE: The endothelin (ET) system is activated in pulmonary arterial hypertension (PAH). The therapeutic value of pharmacological blockade of ET receptors has been demonstrated in various animal models and led to the current approval and continued development of these drugs for the therapy of human PAH. However, we currently incompletely comprehend what local modifications of this system occur as a consequence of PAH, particularly in small resistance arteries, and how this could affect the pharmacological response to ET receptor antagonists with various selectivities for the receptor subtypes. Therefore, the purposes of this study were to evaluate potential modifications of the pharmacology of the ET system in rat pulmonary resistance arteries from monocrotaline (MCT)-induced pulmonary arterial hypertension. EXPERIMENTAL APPROACH: ET-1 levels were quantified by ELISA. PreproET-1, ETA and ETB receptor mRNA expressions were quantified in pulmonary resistance arteries using Q-PCR, while protein expression was evaluated by Western blots. Reactivity to ET-1 of isolated pulmonary resistance arteries was measured in the presence of ETA (A-147627), ETB (A-192621) and dual ETA/B (bosentan) receptor antagonists. KEY RESULTS: In rats with PAH, plasma ET-1 increased (p < 0.001) while pulmonary levels were reduced(p < 0.05). In PAH arteries, preproET-1 (p < 0.05) and ETB receptor (p < 0.001) gene expressions were reduced, as were ETB receptor protein levels (p < 0.05). ET-1 induced similar vasoconstrictions in both groups. In arteries from sham animals, neither bosentan nor the ETA or the ETB receptor antagonists modified the response. In arteries from PAH rats, however, bosentan and the ETA receptor antagonist potently reduced the maximal contraction, while bosentan also reduced sensitivity (p < 0.01). CONCLUSIONS AND IMPLICATIONS: The effectiveness of both selective ETA and dual ETA/B receptor antagonists is markedly increased in PAH. Down-regulation of pulmonary resistance arteries ETB receptor may contribute to this finding.

Endothelin-3-dependent pulmonary vasoconstriction in monocrotaline-induced pulmonary arterial hypertension.

Blockade of the endothelin (ET) system is beneficial in pulmonary arterial hypertension (PAH). The contribution of ET-3 and its interactions with ET receptors have never been evaluated in the monocrotaline (MCT)-induced model of PAH. Vasoreactivity of pulmonary arteries was investigated; ET-3 localization was determined by confocal imaging and gene expression of prepro-ET-3 quantified using RT-PCR. ET-3 plasma levels tended to increase in PAH. ET-3 localized in the media of pulmonary arteries, where gene expression of prepro-ET-3 was reduced in PAH. ET-3 induced similar pulmonary vasoconstrictions in sham and PAH rats. In sham rats, the ET(A) antagonist A-147627 (10nmol/l) significantly reduced the maximal response to ET-3 (E(max) 77+/-1 to 46+/-2%, mean+/-S.E.M., P<0.001), while the ET(B) antagonist A-192621 (1mumol/l) reduced the sensitivity (EC(50) 21+/-7 to 59+/-16nmol/l, P<0.05) without affecting E(max). The combination of both antagonists completely abolished ET-3-induced pulmonary vasoconstriction. In PAH, the ET(A) antagonist further reduced the maximal response to ET-3 and shifted the EC(50) (E(max) 23+/-2%, P<0.001, EC(50) 104+/-24nmol/l, P<0.05), while the ET(B) antagonist only shifted the EC(50) (123+/-36nmol/l, P<0.05) without affecting the E(max). In PAH, dual ET receptor inhibition did not further reduce constriction compared to selective ET(A) inhibition. ET-3 significantly contributes to pulmonary vasoconstriction by activating the ET(B) at low concentration, and the ET(A) at high concentration. The increased inhibitory effect of the ET(A) antagonist in PAH suggests that the contribution of ET(B) to ET-3-induced vasoconstriction is reduced. Although ET-3 is a potent pulmonary vasoconstrictor in PAH, its potential pathophysiologic contribution remains uncertain.

Endothelin-1-induced pulmonary vasoreactivity is regulated by ET(A) and ET(B) receptor interactions.

BACKGROUND: Roles of endothelin (ET) receptors (R) and of the endothelium on ET-1-induced pulmonary vasoreactivity are subjects of debate. This stems from endothelial ET(B)-R that can release both vasodilators and vasoconstrictors. The aim of this study was to evaluate the roles of the endothelium and of ET-Rs on ET-1-induced pulmonary vasoreactivity. METHODS: Pharmacological experiments were performed in isolated rat lungs and in pulmonary resistance arteries. RESULTS: In isolated lungs, ET-1 and the selective ET(B)-R agonist sarafotoxin 6c (S6c) induced a similar vasoconstriction. ET-1 constriction was reduced by a selective ET(A)-R antagonist; however, the selective ET(B)-R antagonist had no significant effect. In preconstricted lungs, ET(B)-R stimulation caused mild vasodilation at low concentrations but severe vasoconstriction at higher concentrations. In isolated arteries, responses to ET-1 and S6c were not different and unaffected by removal of endothelium. Interestingly, concentrations of ET(A)-R and ET(B)-R antagonists that only mildly reduced ET-1 vasoconstriction when used alone, prevented maximal constriction and greatly reduced vascular sensitivity to ET-1 when used in combination. CONCLUSION: In rat lungs, both ET(A)-R and ET(B)-R contribute to ET-1-induced pulmonary vasoconstriction with evidence of interaction between receptors. A mild vasodilator role of the endothelial ET(B)-R is evident only at low agonist concentration and when baseline vascular tone is increased.

Evaluation of endothelin-1-induced pulmonary vasoconstriction following myocardial infarction.

Endothelin (ET) levels are elevated in congestive heart failure secondary to myocardial infarction (MI) and correlate well with the severity of pulmonary hypertension (PH), suggesting that the ET peptide could contribute to the pathophysiology of venous PH. Alterations of pulmonary vasoreactivity to ET after MI and the respective roles of the ET(A) and ET(B) receptors (ET(A)-R and ET(B)-R) have never been evaluated, to our knowledge. MI was induced in rats. Three weeks later, small pulmonary resistance arteries were mounted on a microvascular myograph. Cumulative concentration-response curves to ET-1 and sarafotoxin 6c (S6c) were performed. Response to ET was also assessed in the presence of ET-R antagonists. Heterodimerization of receptors was evaluated by immunoprecipitation of the ET(B)-R, followed by western blotting for the expression of the ET(A)-R. Maximal vasoconstriction and sensitivity to ET-1 were similar in sham and MI with values of 88 +/- 3.9% and 80 +/- 3.8%, respectively. The response to S6c was similarly less in both sham (67 +/- 5.7%) and MI groups (60 +/- 6.6%). When administered alone, the ET(A)-R antagonist (10 nM A-147627.1) and the ET(B)-R antagonist (1 microM A-192621.1) had no significant effect. However, their combination markedly reduced vaso-constriction (52 +/- 5.3%; P < 0.001). The endothelial and medial distribution of ET-Rs was similar in sham and MI groups. In vitro studies demonstrated co-immunoprecipitation of the ET(A)-R and ET(B)-R. Vasoconstriction of isolated resistance pulmonary arteries to ET agonists is not altered after MI. Dual antagonism results in optimal blockade of vasoconstriction, possibly because the ET(A)-R and ET(B)-R can form functional heterodimers.

Chronically elevated endothelin levels reduce pulmonary vascular reactivity to nitric oxide.

UNLABELLED: Although local tissue activation of the endothelin (ET) system contributes to the development of pulmonary hypertension, the impact of isolated chronic plasma hyperendothelinemia on the pulmonary circulation is unknown. METHODS: Mini-osmotic pumps were implanted in rats to deliver ET-1 during 7 or 28 days. After in vivo hemodynamics, the lungs were isolated to derive pressure-flow relations. Small pulmonary arteries ( approximately 250 microm) were mounted on an isometric myograph to study their reactivity. RESULTS: Plasma ET-1 approximately doubled (p < 0.05) after 7 and 28 days. Lung tissue ET-1 level increased fourfold after 7 days (p < 0.001) but was no longer significantly elevated after 28 days. Right ventricular systolic pressure was unaffected. The pulmonary pressure-flow relation shifted upward with a steeper slope (p < 0.05) at 7 days, but not after 28 days. Maximum dilatations to both acetylcholine (p < 0.01) and sodium nitroprusside (p < 0.001) were greatly reduced by approximately 50% after 28 days and were normalized by the addition of the nitric oxide synthase inhibitor L-NNA and the antioxidant N-acetyl-L-cysteine, respectively. CONCLUSION: Chronic hyperendothelinemia reduces the pulmonary vasodilator reserve in response to nitric oxide. Correction by an antioxidant and L-NNA suggests that this relates to increased production of reactive oxygen species, which may have clinical relevance for conditions associated with chronic increase of ET. Further studies are required to determine if, in the long term, this could contribute to the development of pulmonary hypertension.