Neoadjuvant targeted molecular therapies in patients undergoing nephrectomy and inferior vena cava thrombectomy: is it useful?

Objective

To assess the effect of neoadjuvant targeted molecular therapies (TMTs) on size and level of inferior vena cava tumor thrombi and to evaluate their impact on surgical management.

Methods

We retrospectively analyzed the data of 14 patients treated for a clear cell renal cell carcinoma with inferior vena cava thrombi by neoadjuvant TMT before nephrectomy. Clinical, pathological and perioperative data were gathered retrospectively at each institution. The primitive tumor size and the thrombus size were defined by computed tomography before TMT. The tumor thrombus level was defined according to the Novick’s classification.

Results

Before TMT, thrombus level was staged I for 1 (7 %), II for 10 (72 %) and III (21 %) for 3 patients. First-line therapy was sunitinib in 11 cases and sorafenib in 3 cases. Median therapy duration was two cycles (1–5). Three patients experienced major adverse effects (grade III) during TMT. Following TMT, 6 (43 %) patients had a measurable decrease, 6 (43 %) had no change, and 2 (14 %) had an increase in the thrombus. One patient (7 %) had a downstage of thrombus level, 12 (85 %) had stable thrombi, and 1 (7 %) had an upstage. Regarding primary tumor, 7 (50 %), 5 (36 %) and 2 (14 %) patients had a decrease, stabilization and an increase in tumor size, respectively.

Conclusion

Neoadjuvant TMT appears to have limited effects on renal tumor thrombi. This retrospective study failed to demonstrate a significant impact of neoadjuvant TMT on surgical management of clear cell renal cell carcinoma with inferior vena cava tumor thrombi.     

The impact of smoking on pathologic response to neoadjuvant cisplatin-based chemotherapy in patients with muscle-invasive bladder cancer

Purpose

Smoking is the primary etiologic risk factor for bladder cancer and has been implicated in mechanisms of chemoresistance. We investigated smoking as a potential predictor for pathologic outcomes after neoadjuvant chemotherapy (NC) and radical cystectomy (RC) for muscle-invasive bladder cancer.

Methods

We identified 139 patients treated with neoadjuvant cisplatin-based chemotherapy followed by RC for T2-4aN0M0 bladder cancer. Logistic regression was used to evaluate associations between smoking characteristics and pathologic outcomes (pT0, complete response; pT0/pTis/pT1, any response). In a secondary analysis, multivariate Cox regression was used to assess associations between smoking and recurrence-free and cancer-specific survival.

Results

Our cohort consisted of 99 (71 %) males, with a median age of 65 (interquartile range 56, 71). Prevalence of never, former, and current smokers was 25, 45, and 29 %, respectively. In total, 63 patients experienced disease recurrence, 39 died of disease, and 11 died of other causes. There were no statistically significant associations between smoking characteristics and complete (p = 0.5) or any (p = 0.2) pathologic response to NC. Similarly, we did not find any association between smoking characteristics and recurrence (p = 0.6) or cancer-specific survival (p = 0.9).

Conclusions

In this series, smoking characteristics were not found to be predictive of pathologic response after NC and RC, although this analysis was limited by the small study sample size. However, the harmful effects of smoking warrants continued emphasis on smoking cessation counseling in bladder cancer patients.     

Effects of Odanacatib on the Radius and Tibia of Postmenopausal Women: Improvements in Bone Geometry,Microarchitecture, and Estimated Bone Strength

The cathepsin K inhibitor odanacatib (ODN), currently in phase 3 development for postmenopausal osteoporosis, has a novel mechanism of action that reduces bone resorption while maintaining bone formation. In phase 2 studies, odanacatib increased areal bone mineral density (aBMD) at the lumbar spine and total hip progressively over 5 years. To determine the effects of ODN on cortical and trabecular bone and estimate changes in bone strength, we conducted a randomized, double‐blind, placebo‐controlled trial, using both quantitative computed tomography (QCT) and high‐resolution peripheral (HR‐p)QCT. In previously published results, odanacatib was superior to placebo with respect to increases in trabecular volumetric BMD (vBMD) and estimated compressive strength at the spine, and integral and trabecular vBMD and estimated strength at the hip. Here, we report the results of HR‐pQCT assessment. A total of 214 postmenopausal women (mean age 64.0 ± 6.8 years and baseline lumbar spine T‐score –1.81 ± 0.83) were randomized to oral ODN 50 mg or placebo, weekly for 2 years. With ODN, significant increases from baseline in total vBMD occurred at the distal radius and tibia. Treatment differences from placebo were also significant (3.84% and 2.63% for radius and tibia, respectively). At both sites, significant differences from placebo were also found in trabecular vBMD, cortical vBMD, cortical thickness, cortical area, and strength (failure load) estimated using finite element analysis of HR‐pQCT scans (treatment differences at radius and tibia = 2.64% and 2.66%). At the distal radius, odanacatib significantly improved trabecular thickness and bone volume/total volume (BV/TV) versus placebo. At a more proximal radial site, odanacatib attenuated the increase in cortical porosity found with placebo (treatment difference = –7.7%, p = 0.066). At the distal tibia, odanacatib significantly improved trabecular number, separation, and BV/TV versus placebo. Safety and tolerability were similar between treatment groups. In conclusion, odanacatib increased cortical and trabecular density, cortical thickness, aspects of trabecular microarchitecture, and estimated strength at the distal radius and distal tibia compared with placebo. © 2014 American Society for Bone and Mineral Research     

Phosphoproteomic Analysis Reveals Regulatory Mechanisms at the Kidney Filtration Barrier

Diseases of the kidney filtration barrier are a leading cause of ESRD. Most disorders affect the podocytes, polarized cells with a limited capacity for self-renewal that require tightly controlled signaling to maintain their integrity, viability, and function. Here, we provide an atlas of in vivo phosphorylated, glomerulus-expressed proteins, including podocyte-specific gene products, identified in an unbiased tandem mass spectrometry–based approach. We discovered 2449 phosphorylated proteins corresponding to 4079 identified high-confidence phosphorylated residues and performed a systematic bioinformatics analysis of this dataset. We discovered 146 phosphorylation sites on proteins abundantly expressed in podocytes. The prohibitin homology domain of the slit diaphragm protein podocin contained one such site, threonine 234 (T234), located within a phosphorylation motif that is mutated in human genetic forms of proteinuria. The T234 site resides at the interface of podocin dimers. Free energy calculation through molecular dynamic simulations revealed a role for T234 in regulating podocin dimerization. We show that phosphorylation critically regulates formation of high molecular weight complexes and that this may represent a general principle for the assembly of proteins containing prohibitin homology domains.The kidney filter consists of three layers: fenestrated endothelial cells, the glomerular basement membrane, and podocytes.¹ Damage to any of these compartments becomes clinically evident as proteinuria and the development of kidney disease.² Of particular importance for the regulation of podocyte biology through signaling is the slit diaphragm, a specialized intercellular junction that bridges the 40-nm gap in between foot processes of neighboring podocytes. It also serves as a signaling platform regulating podocyte function. Mutations in genes encoding for components of the slit diaphragm, such as nephrin,³ podocin,⁴ CD2AP,⁵ and TRPC6,^6,7 are important causes of genetic forms of proteinuria. Alteration of these proteins results in defective signaling causing podocyte dysfunction, progressive glomerulosclerosis, and kidney failure. The slit diaphragm protein complex is a lipid-multiprotein supercomplex.⁸ Of central importance to the integrity and function of the protein complex is the prohibitin homology (PHB) domain protein podocin,⁹ which forms multimeric complexes and is required to control signal transduction through associated transmembrane proteins.^10,11Signaling processes governing podocyte function, integrity, and survival largely depend on signaling processes involving phosphorylation.^12,13 Comprehensive analyses of the signaling events in podocytes in vivo have been hampered by the fact that interference with these signaling cascades by genetic deletion often results in massively disrupted and dysfunctional podocytes. One of the primary aims of this study was to use phosphoproteomics to analyze thousands of phosphorylation sites in native murine glomeruli within single samples. Within this study, we show that this approach allows the introduction of new concepts into signaling processes at the kidney filtration barrier.     

Renal Outcomes in Patients with Type 1 Diabetes and Macroalbuminuria

Macroalbuminuria, defined as urine albumin excretion rate (AER)≥300 mg/d, has long been considered a stage of irreversible kidney damage that leads reliably to GFR loss. We examined the long-term renal outcomes of persons with type 1 diabetes who developed incident macroalbuminuria during the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) study. One hundred fifty-nine participants developed incident macroalbuminuria and were subsequently followed for a median duration of 9 years (maximum of 25 years). At the time of macroalbuminuria diagnosis, mean (SD) age was 37 (9) years, mean (SD) duration of diabetes was 17 (5) years, median AER was 524 mg/d, and mean (SD) eGFR was 108 (20) ml/min per 1.73 m². Ten years after macroalbuminuria diagnosis, the cumulative incidence of a sustained reduction in AER to <300 mg/d was 52%, mostly but not entirely under treatment with renin-angiotensin system inhibitors. The cumulative incidence of impaired GFR (sustained eGFR<60 ml/min per 1.73 m²) 10 years after macroalbuminuria diagnosis was 32%, including 16% who developed ESRD. Lower hemoglobin A1c and BP and regression to AER<300 mg/d were associated with reduced risk of developing impaired GFR. In conclusion, people with type 1 diabetes who develop macroalbuminuria are at high risk of progressive kidney disease. However, through at least 10 years of follow-up, AER could often be controlled, and GFR frequently remained in the normal range.Macroalbuminuria, defined as urine albumin excretion rate (AER)≥300 mg/d, has long been considered a stage of irreversible kidney damage that leads reliably to GFR loss.¹ In early published type 1 diabetes cohorts, macroalbuminuria was associated with a 15-year cumulative incidence of ESRD as high as 75%.^2,3 However, contemporary long-term renal outcomes of macroalbuminuria have not been fully characterized.The Diabetes Control and Complications Trial (DCCT) and its observational follow-up, the Epidemiology of Diabetes Interventions and Complications (EDIC) study, present a valuable opportunity to examine macroalbuminuria and its long-term clinical outcomes. In DCCT/EDIC, the onset of macroalbuminuria can be defined with confidence using frequent longitudinal measurements of AER, participants have been followed for up to 25 years after the diagnosis of macroalbuminuria, and outcomes were meticulously recorded using standardized methods. Previous work in this cohort has shown that most cases of impaired GFR are preceded by macroalbuminuria,⁴ which is associated with a 50-fold higher risk of developing impaired GFR (eGFR<60 ml/min per 1.73 m²).⁵ Here, we extend these studies by comprehensively evaluating the long-term renal outcomes of incident macroalbuminuria in the DCCT/EDIC cohort and examining the risk factors for its progression to impaired GFR.     

Patient- and Provider-Reported Information about Transplantation and Subsequent Waitlisting

Because informed consent requires discussion of alternative treatments, proper consent for dialysis should incorporate discussion about other renal replacement options including kidney transplantation (KT). Accordingly, dialysis providers are required to indicate KT provision of information (KTPI) on CMS Form-2728; however, provider-reported KTPI does not necessarily imply adequate provision of information. Furthermore, the effect of KTPI on pursuit of KT remains unclear. We compared provider-reported KTPI (Form-2728) with patient-reported KTPI (in-person survey of whether a nephrologist or dialysis staff had discussed KT) in a prospective ancillary study of 388 hemodialysis initiates. KTPI was reported by both patient and provider for 56.2% of participants, by provider only for 27.8%, by patient only for 8.3%, and by neither for 7.7%. Among participants with provider-reported KTPI, older age was associated with lack of patient-reported KTPI. Linkage with the Scientific Registry for Transplant Recipients showed that 20.9% of participants were subsequently listed for KT. Patient-reported KTPI was independently associated with a 2.95-fold (95% confidence interval [95% CI], 1.54 to 5.66; P=0.001) higher likelihood of KT listing, whereas provider-reported KTPI was not associated with listing (hazard ratio, 1.18; 95% CI, 0.60 to 2.32; P=0.62). Our findings suggest that patient perception of KTPI is more important for KT listing than provider-reported KTPI. Patient-reported and provider-reported KTPI should be collected for quality assessment in dialysis centers because factors associated with discordance between these metrics might inform interventions to improve this process.     

Adherence to surveillance guidelines after radical cystectomy: A population-based analysis

ObjectivesSurveillance after radical cystectomy is recommended to detect tumor recurrence and treatment complications. We evaluated adherence to National Comprehensive Cancer Network (NCCN) guidelines using a large population-based database.Methods and materialsThe Surveillance, Epidemiology, and End Results–Medicare database was used to identify patients aged ≥66 years diagnosed with nonmetastatic bladder cancer who had undergone radical cystectomy between 2000 and 2007. Medicare claims information identified recommended surveillance tests for 2 years after cystectomy as outlined in the NCCN guidelines. Adherence was defined as receipt of urine cytology and imaging of the chest, abdomen, and pelvis in each year. We evaluated the effect of patient and provider characteristics on adherence, controlling for demographic and disease characteristics.ResultsOf 3,757 patients who had undergone radical cystectomy, 2,990 (80%) were alive after 2 years. Adherence to all recommended investigations was 17% for the first and the second years following surgery. Among patients surviving 2 years, only 9% had complete surveillance in both years. In either year, adherence was less likely in patients with advanced pathologic stage (III/IV) (adjusted odds ratio [AOR] = 0.74, 95% CI: 0.60–0.91) and unmarried patients (AOR = 0.82, 95% CI: 0.68–0.99). Adherence was more likely in patients treated by high-volume surgeons (AOR = 2.00, 95% CI: 1.70–2.36) and those who saw a medical oncologist (AOR = 1.52, 95% CI: 1.27–1.82). We also observed significant geographic variability in adherence.ConclusionPatterns of surveillance after radical cystectomy deviate considerably from NCCN recommendations. Despite increased utilization of radiographic imaging investigations, the omission of urine cytology significantly contributed to the low rate of overall adherence to surveillance guidelines. Uniform adherence to surveillance guidelines was observed in patients treated by high-volume surgeons. This suggests an important opportunity for quality improvement in bladder cancer care.