Cystatin-C is an independent prognostic factor for survival in multiple myeloma and is reduced by bortezomib administration

A novel prognostic model to predict prognosis of patients with osteosarcoma based on clinical characteristics and blood biomarkers

Purpose: Osteosarcoma (OSC) is a high-morbidity bone cancer with an unsatisfactory prognosis. Timely and accurate assessment the overall survival (OS) and progression-free survival (PFS) in patients with OSC are required to guide and select the best treatment. This study aimed to develop a simple, convenient and low-cost prognostic model based on clinical characteristics and blood biomarkers for predicting OS and PFS in OSC patients. Methods: Overall, 158 patients with OSC included from the Sun Yat-sen University Cancer Center in this retrospective study. LASSO-Cox algorithm was used to shrink predictive factor size and established a prognostic risk model for predicting OS and PFS in OSC patients. The predictive ability of the survival model was compared to the Tumor Node Metastasis (TNM) stage and clinical treatment by concordance index (C-index), time-dependent receiver operating characteristic (td-ROC) curve, decision curve analysis (DCA), net reclassification improvement index (NRI), and integrated discrimination improvement index (IDI). Results: Based on results from the LASSO-Cox method, gender, family history of cancer, monocyte (M), red blood cell (RBC), lactic dehydrogenase (LDH), and cystatin C (Cys-C) were identified to construct a novel predictive model for the OSC patients. The C-index of the prognostic model to predict OS and PFS were 0.713 (95% CI = 0.630 - 0.795) and 0.636 (95% CI = 0.577 - 0.696), respectively, which were higher than the OS and PFS of TNM stage and clinical treatment. Td-ROC curve and DCA of the predictive model also demonstrated good predictive accuracy and discriminatory power of OS and PFS compared to TNM stage and treatment. Moreover, the prognostic model performed well across all time frames (1-, 3-, and 5-year) with regards to the IDI and NRI in comparison to the TNM stage, and clinical treatment. Conclusion: The simple, convenient and low-cost prognostic model we developed demonstrated favorable performance for predicting OS and PFS in OSC patients, which may serve as a useful tool for physicians to provide personalized survival prediction for OSC patients.

Renal Response Criteria for Clinical Trials in Amyloid Light Chain Amyloidosis

Immunoglobin light chain (AL) amyloidosis is a rare disease characterized by organ deposition of amyloid fibrils, most commonly in the heart and kidney. Disease heterogeneity necessitates organ-specific assessment to determine prognosis and response or progression. To facilitate development of new therapies, the Amyloidosis Forum (a public-private partnership between the US Food and Drug Administration and the nonprofit Amyloidosis Research Consortium) held a series of meetings and formed multiple working groups to identify clinical trial end points and analytic strategies. This report summarizes the recommendations of Renal Working Group. Estimated glomerular filtration rate (eGFR) and proteinuria were selected to evaluate eligibility, response, and/or progression in the context of investigational clinical trials for patients with AL amyloidosis. Accurate response assessments at the earliest possible time point were emphasized. The context of use, specific patient population, and the investigational therapeutic mechanism should ultimately drive selection of appropriate end points to evaluate renal response/progression in AL amyloidosis clinical trials.

Associations of serum cystatin C concentrations with total mortality and mortality of 12 site-specific cancers

Purpose

Cystatin C (CysC), beyond its biomarker role of renal function, has been implicated in various physical and pathological activities. However, the impact of serum CysC on cancer mortality in a general population remains unknown. We aimed to examine the associations of serum CysC concentrations with total mortality and mortality of 12 site-specific cancers.

Methods

We included 241,008 participants of the UK Biobank cohort with CysC measurements who had normal creatinine-based estimated glomerular filtration rates and were free of cancer and renal diseases at baseline (2006-2010). Death information was obtained from the National Health Service death records through 28 February 2021. Multivariable Cox proportional hazards models were used to compute hazard ratios (HR) per one standard deviation increase in log-transformed CysC concentrations and 95% confidence intervals (95% CI) for mortality.

Results

Over a median follow-up of 12.1 (interquartile range, 11.3-12.8) years, 5,744 cancer deaths occurred. We observed a positive association between serum CysC concentrations and total cancer mortality (HR = 1.16, 95% CI: 1.12-1.20). Specifically, participants with higher serum CysC concentrations had increased mortality due to lung cancer (HR = 1.12, 95% CI: 1.05-1.20), blood cancer (HR = 1.29, 95% CI: 1.16-1.44), brain cancer (HR = 1.19, 95% CI: 1.04-1.36), esophageal cancer (HR = 1.20, 95% CI: 1.05-1.37), breast cancer (HR = 1.18, 95% CI: 1.03-1.36), and liver cancer (HR = 1.49, 95% CI: 1.31-1.69).

Conclusion

Our findings indicate that higher CysC concentrations are associated with increased mortality due to lung, blood, brain, esophageal, breast, and liver cancers. Future studies are necessary to clarify underlying mechanisms.

Clinical implications and predictive value of the creatinine‑cystatin C ratio in patients with multiple myeloma and renal impairment

The creatinine (Cr)-cystatin C ratio (CCR) at the time of cancer diagnosis is associated with survival; however, to the best of our knowledge, the association between this ratio and mortality in patients with multiple myeloma and renal impairment (RI) is unclear. Therefore, the present study aimed to assess this association, as well as disease prognosis and the clinical significance of the CCR in patients with multiple myeloma and RI. The present retrospective study included 191 patients diagnosed with multiple myeloma and RI between 2012 and 2022. The predictive value of the CCR was evaluated using area under the receiver operating characteristic curve (AUC) values. The factors affecting overall survival (OS) were assessed using uni- and multivariate logistic regression analyses. The effect of the CCR on survival was evaluated using a Cox regression model and the Kaplan-Meier method. There was a significant association between low CCR and poor progression-free survival (PFS) and overall survival (OS). The 1-, 2- and 3-year PFS and OS rates in patients with a low CCR were significantly lower than those in patients with a high CCR. The 1-, 2- and 3-year AUC values of the CCR were 0.712, 0.764 and 0.746 respectively. Multivariate analysis revealed sex, age, Cr levels, CCR and C-reactive protein levels as independent prognostic factors affecting OS rates. The CCR is a potential prognostic indicator in patients with multiple myeloma with RI and is associated with clinical stages.

Cystatin C-Based Equations Detect Hidden Kidney Disease and Poor Prognosis in Newly Diagnosed Patients with Multiple Myeloma

Objectives. The aim of this study was to compare the creatinine equations with cystatin C (CysC) equations to define renal impairment (RI) in newly diagnosed multiple myeloma (MM) patients and to analyse the equation that allows for identifying patients with more and worse prognostic factors. Methods. Renal function was evaluated prospectively in 61 patients with newly diagnosed untreated MM employing CKD-EPI and CAPA equations. The comparison was conducted using Bland–Altman graphics and Cohen’s Kappa statistic. Mann–Whitney T and Chi-square tests were used, and univariate and multivariate analyses were carried out. Results. According to the IMWG criteria, 26% of patients showed RI (3 women/13 men) whilst the use of CysC equations allowed us to identify up to 39% of patients (7 women/17 men). The CAPA equation was less biased and dispersed and more sensitive than CKD-EPI-creatinine. Furthermore, univariate analysis unveiled an association between decreased CKD-EPI-CysC and poor prognosis based on R-ISS-3. Conclusions. The IMWG criteria may underestimate kidney disease, mostly in women, which could affect the dose received as well as its toxicity. Altogether, our data suggest that equations that include CysC are more accurate to detect hidden kidney disease, as well as patients with more and worse prognostic factors, in newly diagnosed MM.

Association between preoperative serum Cystatin-C levels and postsurgical oncological prognosis in patients with PRCC: A retrospective cohort study

OBJECTIVE

Cystatin-C (Cys-C) is a predictor of several malignancies. However, whether Cys-C levels predict prognosis in patients with papillary renal cell carcinoma (PRCC) remains uncertain. The aim of this study was to assess the correlation between Cys-C and clinical outcomes in patients with PRCC.

METHODS

The medical records of 137 patients with PRCC who underwent surgery at our institution from January 2008 to December 2020 were retrospectively analyzed. Data were divided into two subgroups based on cutoff values and the relationship between the Cys-C group and their clinical outcomes was assessed.

RESULTS

By the last follow-up, 62 patients had died of various causes, 53 of whom died from PRCC. Sixty patients suffered recurrence or metastasis during follow-up. Based on the cutoff value, the patients were divided into two groups: low Cys-C group (Cys-C < 1.25 mg/L, n = 92) and high Cys-C group (Cys-C ≥ 1.25 mg/L, n = 45). Pathological classification and serum Cys-C levels were shown to be independent prognostic factors affecting clinical outcomes, according to multivariate Cox regression analysis (p < 0.05). After adjusting the Cox proportional hazards model, the risk of death was elevated in the high Cys-C group. The results of the area under the curve for time-dependent receiver operating characteristics analysis indicated that Cys-C is a stable and reliable prognostic biomarker for predicting survival in patients with PRCC. Forest plots, constructed to better reflect the comparison of hazard ratios between the two groups, confirmed that Cys-C levels were significantly associated with worsening overall survival.

CONCLUSION

This study is the first to examine the relationship between preoperative serum Cys-C levels and prognostic overall survival in patients with PRCC. Cys-C may be a useful biomarker for preoperative screening of high-risk patients who may require adjuvant therapy.

The role of cystatin C in multiple myeloma

INTRODUCTION

Renal insufficiency is one of the common complications in multiple myeloma (MM) and an independent factor indicating a poor prognosis. Cystatin C (Cys C) is considered to be expected to replace creatinine to calculate glomerular filtration rate due to its own characteristics. Gene expression analysis suggested that cystatin C is up-regulated nearly 50-fold in patients with multiple myeloma.

METHODS

To further clarify the role of cystatin C in multiple myeloma, we retrospectively evaluated pretreatment cystatin C levels in 195 newly diagnosed patients through statistical analysis.

RESULTS

The elevation of serum cystatin C was positively related to the elevation of serum creatinine (P < .001), LDH (P = .006), β2-microglobulin (P < .001), bone marrow plasma cell proportion (P = .005) and the reduction of hemoglobin levels (P < .001). Patients with serum cystatin C levels >1.6 mg/L had a significantly shorter progression-free survival (PFS) or overall survival (OS) than patients with serum cystatin C levels <1.6 mg/L (median PFS: median unreached vs 16.7 months, P < .001; median OS: 68 months vs 42 months, P = .014). Although serum cystatin C is not an independent prognostic factor of OS and PFS in patients with multiple myeloma, serum cystatin C can be considered as a sensitive indicator to differentiate well OS and PFS in the group of ISS II patients.

CONCLUSION

Serum cystatin C is associated with tumor burden of multiple myeloma and cystatin C can further differentiate the prognosis of ISS II patients. More prospective studies are required to explore the role of serum cystatin C in multiple myeloma.

Prognostic Value of Pretreatment Serum Cystatin C Level in Nasopharyngeal Carcinoma Patients in the Intensity-modulated Radiotherapy Era

Purpose

Serum cystatin C has been considered as a significant prognostic factor for various malignancies. This study aimed to evaluate the relationship between serum cystatin C level before antitumor treatment and the prognosis of nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT).

Patients and Methods

A cohort of 2077 NPC patients were enrolled between April 2009 and September 2012. The Kaplan–Meier curves and log rank tests were used to determine the differences of overall survival (OS) and disease-free survival (DFS). Univariate and multivariate Cox regression analyses were used to determine independent prognostic factors.

Results

Overall, 362/2077 (17.4%) patients had high serum cystatin C level, and they were older and more male (both P<0.001), and they had higher TNM stage (all P<0.05). Kaplan–Meier analysis revealed that patients with high serum cystatin C had worse OS (P<0.001) and DFS (P<0.001). Univariate and multivariate Cox regression analysis showed that high serum cystatin C level was an independent prognostic predictor of OS (HR: 1.56, 95%CI: 1.25–1.95) and DFS (HR: 1.38, 95%CI: 1.13–1.68). Subgroup analysis based on TNM stage revealed that advanced-stage NPC patients with high serum cystatin C had poorer OS (P<0.001) and DFS (P<0.001).

Conclusion

Our results revealed that high serum cystatin C level before antitumor treatment can predict clinical outcomes of NPC patients treated with IMRT, and it can guide clinicians to formulate more personalized therapy for NPC patients.

The role of cystatin C as a proteasome inhibitor in multiple myeloma

Objectives: Bone destruction and renal impairment are two frequent complications of multiple myeloma (MM). Cystatin C, an extracellular cysteine proteinase inhibitor, is encoded by the housekeeping gene CST3 and associated with human tumors. The role of cystatin C in multiple myeloma has been revealed recently. The purpose of this study was to explore the role of cystatin C as a proteasome inhibitor in multiple myeloma. Methods : A comprehensive literature review was conducted through Pubmed to summarize the published evidence on cystatin C in multiple myeloma. English literature sources since 1999 were searched, using the terms cystatin C, multiple myeloma. Results: cystatin C is a sensitive indicator for the diagnosis of myeloma nephropathy and has a dual role in myeloma bone disease. Also, cystatin C reflects tumor burden and is strongly associated with prognosis in patients with multiple myeloma. Conclusion: Cystatin C have great diagnostic and prognostic value in multiple myeloma. It can provide a new treatment direction for MM by designing and searching for antagonists of cystatin C or cysteine protease agonists using cystatin C as a therapeutic target.

Evaluating the Relationship of GDF-15 with Clinical Characteristics, Cardinal Features, and Survival in Multiple Myeloma

Growth differentiation factor 15 (GDF-15), a member of the transforming growth factor-β superfamily, participates in processes associated with myeloma development and its end-organ complications. It plays a significant role in both physiological and abnormal erythropoiesis and regulates iron homeostasis through modulation of hepcidin. It is abnormally secreted in marrow stromal cells of patients with multiple myeloma (MM), which may reflect the tumor microenvironment. We analyzed the associations of serum GDF-15 with clinical characteristics of 73 MM patients (including asymptomatic MM) and the laboratory indices of renal function, anemia, and inflammation. Baseline serum GDF-15 was studied as the predictor of two-year survival. We defined five clinically relevant subgroups of patients (symptomatic MM only, patients with and without remission, patients on chemotherapy, and without treatment). Increased GDF-15 concentrations were associated with more advanced MM stage, anemia, renal impairment (lower glomerular filtration and higher markers of tubular injury), and inflammation. Most of the results were confirmed in the subgroup analysis. Serum cystatin C and urine neutrophil gelatinase-associated lipocalin were associated with GDF-15 independently of other variables. In the studied MM patients, GDF-15 did not significantly predict survival (p = 0.06). Our results suggest that serum GDF-15 reflects myeloma burden and shares a relationship with several markers of prognostic significance, as well as major manifestations.

Circulating Soluble Urokinase-Type Plasminogen Activator Receptor Levels Reflect Renal Function in Newly Diagnosed Patients with Multiple Myeloma Treated with Bortezomib-Based Induction

(1) Background: Soluble urokinase-type plasminogen activator receptor (suPAR) has been implicated in the pathogenesis of kidney disease in different disease settings. The aim of this study was to investigate a possible link between suPAR circulating levels and renal impairment (RI) in newly diagnosed patients with symptomatic multiple myeloma (NDMM) before and after frontline therapy with bortezomib-based regimens. (2) Methods: We studied 47 NDMM patients (57% males, median age 69.5 years) before the administration of anti-myeloma treatment and at best response to bortezomib-based therapy. suPAR was measured in the serum of all patients and of 24 healthy matched controls, using an immuno-enzymatic assay (ViroGates, Denmark). (3) Results: suPAR levels were elevated in NDMM patients at diagnosis compared to healthy individuals (p < 0.001). suPAR levels strongly correlated with disease stage (p-ANOVA < 0.001). suPAR levels both at diagnosis and at best response negatively correlated with estimated glomerular filtration rate (eGFR) values (p < 0.001). Interestingly, no significance changes in suPAR levels were observed at best response compared to baseline values (p = 0.31) among 18 responding patients with baseline eGFR < 50 mL/min/1.73 m². (4) Conclusions: SuPAR levels reflect renal function in NDMM patients treated with bortezomib-based induction. Responders may have elevated circulating suPAR levels, possibly reflecting persistent kidney damage, despite their renal response.

New Markers of Renal Failure in Multiple Myeloma and Monoclonal Gammopathies

* Correspondence: kasiajanda@op [...].

The preoperative serum cystatin-C as an independent prognostic factor for survival in upper tract urothelial carcinoma

Cystatin-C (Cys-C) has been reported as a valuable prognostic biomarker in various malignancies. However, its effect on upper tract urothelial carcinoma (UTUC) patients has not been investigated before. Thus, to explore the impact of Cys-C on survival outcomes in patients undergoing radical nephroureterectomy (RNU), a total of 538 patients with UTUC who underwent RNU between 2005 and 2014 in our center (West China Hospital, Chengdu, China) were included in this study. Kaplan–Meier method and Cox regression analyses were performed to assess the relationship between Cys-C and survival outcomes using SPSS version 22.0. The cutoff value of Cys-C was set as 1.4 mg l⁻¹ using the receiver operating characteristic (ROC) curves and Youden index. The mean age of patients included was 66.1 ± 11.1 years, and the median follow-up duration was 38 (interquartile range: 19–56) months. Overall, 162 (30.1%) patients had elevated Cys-C, and they were much older and had worse renal function than those with Cys-C <1.4 mg l⁻¹ (both P < 0.001). Meanwhile, Kaplan–Meier analysis revealed that the group with elevated Cys-C had worse cancer-specific survival (CSS, P = 0.001), disease recurrence-free survival (RFS, P = 0.003), and overall survival (OS, P < 0.001). Multivariable Cox analysis suggested that the elevated Cys-C was identified as an independent prognostic predictor of CSS (hazard ratio [HR]: 1.997, 95% confidential interval [CI]: 1.331–2.996), RFS (HR: 1.429, 95% CI: 1.009–2.023), and OS (HR: 1.989, 95% CI: 1.366–2.896). In conclusion, our result revealed that the elevated preoperative serum Cys-C was significantly associated with worse outcomes in UTUC patients undergoing RNU.

Cystatin C: A Primer for Pharmacists

Pharmacists are at the forefront of dosing and monitoring medications eliminated by or toxic to the kidney. To evaluate the effectiveness and safety of these medications, accurate measurement of kidney function is paramount. The mainstay of kidney assessment for drug dosing and monitoring is serum creatinine (SCr)-based estimation equations. Yet, SCr has known limitations including its insensitivity to underlying changes in kidney function and the numerous non-kidney factors that are incompletely accounted for in equations to estimate glomerular filtration rate (eGFR). Serum cystatin C (cysC) is a biomarker that can serve as an adjunct or alternative to SCr to evaluate kidney function for drug dosing. Pharmacists must be educated about the strengths and limitations of cysC prior to applying it to medication management. Not all patient populations have been studied and some evaluations demonstrated large variations in the relationship between cysC and GFR. Use of eGFR equations incorporating cysC should be reserved for drug management in scenarios with demonstrated outcomes, including to improve pharmacodynamic target attainment for antibiotics or reduce drug toxicity. This article provides an overview of cysC, discusses evidence around its use in medication dosing and in special populations, and describes practical considerations for application and implementation.

Cystatins in cancer progression: More than just cathepsin inhibitors

Cystatins are endogenous and reversible inhibitors of cysteine peptidases that are important players in cancer progression. Besides their primary role as regulators of cysteine peptidase activity, cystatins are involved in cancer development and progression through proteolysis-independent mechanisms. Mechanistic studies of cystatin function revealed that they affect all stages of cancer progression including tumor growth, apoptosis, invasion, metastasis and angiogenesis. Recently, the involvement of cystatins in the antitumor immune responses was reported. In this review, we discuss molecular mechanisms and clinical aspects of cystatins in cancer. Altered expression of cystatins in cancer resulting in harmful excessive cysteine peptidase activity has been a subject of several studies in order to find correlations with clinical outcome and therapy response. However, involvement in anti-tumor immune response and signaling cascades leading to cancer progression designates cystatins as possible targets for development of new anti-tumor drugs.

Development of an Initial Conceptual Model of Multiple Myeloma to Support Clinical and Health Economics Decision Making

Background. We aimed to develop and validate a conceptual model of multiple myeloma (MM) that characterizes the attributes affecting disease progression and patient outcomes, and the relationships between them. Methods. Systematic and targeted literature reviews identified disease- and patient-specific attributes of MM that affect disease progression and outcomes. These attributes were validated by a Delphi panel of four international MM experts, and a physician-validated model was constructed. Real-world clinical data from the Czech Registry of Monoclonal Gammopathies (RMG) was used to confirm the relationships between attributes using pairwise correlations and multiple Cox regression analysis. Results. The Delphi panel reached consensus that most cytogenetic abnormalities influenced disease activity, which results in symptoms and complications and affects overall survival (OS). Comorbidities and complications also affect OS. The entire panel agreed that quality of life was influenced by comorbidities, age, complications, and symptoms. Consensus was not reached in some cases, in particular, the influence of del(17p) on complications. The relationships between attributes were confirmed using pairwise analysis of real-world data from the Czech RMG; most of the correlations identified were statistically significant and the strength of the correlations changed with successive relapses. Czech RMG data were also used to confirm significant predictors of OS included in the model, such as age, Eastern Cooperative Oncology Group performance status, and extramedullary disease. Conclusions. This validated conceptual model can be used for economic modeling and clinical decision making. It could also inform the development of disease-based models to explore the impact of disease progression and treatment on outcomes in patients with MM.

Renal Dysfunction and Recovery following Initial Treatment of Newly Diagnosed Multiple Myeloma

Introduction

Renal insufficiency (RI) in Multiple Myeloma (MM) portends a higher tumor burden and worse prognosis. Reversal of RI in newly diagnosed MM (NDMM) improves patient outcomes, but it is unknown if there is a disparity in renal recovery in NDMM between African Americans (AA) and non-African Americans.

Methods

A retrospective chart review was conducted of 690 patients with NDMM at Rush University Medical Center from 2005 to 2016. 118 patients (59 AA and 59 non-AA) with NDMM and an estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m² at the time of diagnosis were identified and analyzed. The time to best renal response and best eGFR achieved during initial myeloma therapy were tabulated.

Results

Median eGFR at the time of diagnosis was similar between the AA and non-AA groups (47.89 versus 51.95, p=0.56). Median absolute change in eGFR after initial therapy was significantly higher in the AA (+33.64) versus the non-AA group (+21.07, p=0.00183). This difference remained whether the baseline eGFR at diagnosis was <90 or <60 mL/min/1.73 m².

Discussion

AA patients with NDMM treated in the era of novel agents have greater improvement in renal function in comparison to non-AA patients, regardless of myeloma response. The biological underpinnings for this disparity require further investigation.

Cysteine cathepsins as a prospective target for anticancer therapies-current progress and prospects

Cysteine cathepsins (CTS), being involved in both physiological and pathological processes, play an important role in the human body. During the last 30 years, it has been shown that CTS are highly upregulated in a wide variety of cancer types although they have received a little attention as a potential therapeutic target as compared to serine or metalloproteinases. Studies on the increasing problem of neoplastic progression have revealed that secretion of cell-surface- and intracellular cysteine proteases is aberrant in tumor cells and has an impact on their growth, invasion, and metastasis by taking part in tumor angiogenesis, in apoptosis, and in events of inflammatory and immune responses. Considering the role of CTS in carcinogenesis, inhibition of these enzymes becomes an attractive strategy for cancer therapy. The downregulation of natural CTS inhibitors (CTSsis), such as cystatins, observed in various types of cancer, supports this claim. The intention of this review is to highlight the relationship of CTS with cancer and to present illustrations that explain how some of their inhibitors affect processes related to neoplastic progression.

Cystatin C Is a More Reliable Biomarker for Determining eGFR to Support Drug Development Studies

Glomerular filtration rate (GFR) is routinely used as a surrogate endpoint for the development of investigational drugs in clinical trials. GFR and staging of chronic kidney disease are typically assessed by measuring the concentration of endogenous serum biomarkers such as albumin and creatinine. However, creatinine is subject to high biological variability, and levels of creatinine do not rise until nearly 50% of kidney function is damaged, leading to inaccurate chronic kidney disease staging and false negatives. A newer biomarker for GFR, cystatin C, has been shown to be subject to less biological interference and more sensitive to early declines in kidney function. Cystatin C has also been shown to outperform creatinine as an indicator of true GFR and to add information about the occurrence of acute kidney injury. Comparison studies of cystatin C and creatinine continue to demonstrate its increased accuracy and sensitivity for changes in true GFR. While challenges remain for use of cystatin C, international agencies and working groups continue to validate cystatin C as a biomarker and accompanying GFR estimating equations for diagnostic and drug development use. In this review, we summarize these comparison studies, regulatory and industry guidelines, and clinical trial case studies for use of cystatin C in drug development.

Renal outcomes in patients with AL amyloidosis: Prognostic factors, renal response and the impact of therapy

A staging system for patients with renal AL amyloidosis, based on eGFR (<50 ml/min/1.73 m² ) and proteinuria (≥5 g/day) at diagnosis, as well as criteria for renal progression (≥25% eGFR reduction) and response (≥30% reduction of proteinuria without renal progression) were recently proposed. We validated these criteria in a cohort of 125 patients with renal AL amyloidosis, mostly treated with bortezomib or lenalidomide. We confirmed the prognostic value of the renal staging system but also identified the limitations of renal progression criteria which are based only on eGFR reduction. We identified the ratio of 24h proteinuria to eGFR as a sensitive marker of renal risk which also accounts for changes in both proteinuria and eGFR: 24h proteinuria/eGFR ratio <30 (in mg/ml/min/1.73 m² ) was associated with a 2-year progression to dialysis rate of 0% compared to 9% for a ratio of 31-99 and 35% for a ratio ≥100 (P < .001). In landmark analysis, patients who achieved a reduction of this ratio by at least 25% or ≤100 (if initially >100) at 3 months had a 2-year progression to dialysis of 0% vs 24% for patients who either did not reduce to or still had a ratio >100 (P = .001); similar results were obtained by applying the same criteria at 6 months; thus, the evaluation of treatment effect on renal function may be identified early. Furthermore, primary bortezomib-based therapy was more effective than lenalidomide-based therapy, in terms of renal outcomes, especially in patients at intermediate renal risk, but without affecting overall survival.

Dexamethasone Modifies Cystatin C-Based Diagnosis of Acute Kidney Injury During Cisplatin-Based Chemotherapy

BACKGROUND/AIMS

Plasma cystatin C (pCysC) may be superior to serum creatinine (sCr) as a surrogate of GFR. However, the performance of pCysC for diagnosing acute kidney injury (AKI) after cisplatin-based chemotherapy is potentially affected by accompanying corticosteroid anti-emetic therapy and hydration.

METHODS

In a prospective observational study pCysC, sCr, urinary kidney injury molecule-1 (KIM-1), and urinary clusterin were measured over 2 weeks in 27 patients given first-cycle chemotherapy. The same variables were measured over 2 weeks in Sprague-Dawley rats given a single intraperitoneal injection of dexamethasone, cisplatin, or both, and in controls.

RESULTS

In patients, pCysC increases were greater than sCr 41% vs. 16%, mean paired difference 25% (95% CI: 16-34%)], relative increases were ≥ 50% in 9 patients (35%) for pCysC compared with 2 (8%) for sCr (p = 0.04) and increases in sCr were accompanied by increased KIM-1 and clusterin excretion, but increases in pCysC alone were not. In rats, dexamethasone administration produced dose-dependent increases in pCysC (and augmented cisplatin-induced increases in pCysC), but did not augment histological injury, increases in sCr, or KIM-1 and clusterin excretion.

CONCLUSIONS

In the presence of dexamethasone, elevation of pCysC does not reliably diagnose AKI after cisplatin-based chemotherapy.

Proteomic analysis of bronchoalveolar lavage fluid (BALF) from lung cancer patients using label-free mass spectrometry

BACKGROUND

Lung cancer is the leading cause of cancer-related mortality in both men and women throughout the world. The need to detect lung cancer at an early, potentially curable stage, is essential and may reduce mortality by 20%. The aim of this study was to identify distinct proteomic profiles in bronchoalveolar fluid (BALF) and plasma that are able to discriminate individuals with benign disease from those with non-small cell lung cancer (NSCLC).

METHODS

Using label-free mass spectrometry analysis of BALF during discovery-phase analysis, a significant number of proteins were found to have different abundance levels when comparing control to adenocarcinoma (AD) or squamous cell lung carcinoma (SqCC). Validation of candidate biomarkers identified in BALF was performed in a larger cohort of plasma samples by detection with enzyme-linked immunoassay.

RESULTS

Four proteins (Cystatin-C, TIMP-1, Lipocalin-2 and HSP70/HSPA1A) were selected as a representative group from discovery phase mass spectrometry BALF analysis. Plasma levels of TIMP-1, Lipocalin-2 and Cystatin-C were found to be significantly elevated in AD and SqCC compared to control.

CONCLUSION

The results presented in this study indicate that BALF is an important proximal biofluid for the discovery and identification of candidate lung cancer biomarkers.

GENERAL SIGNIFICANCE

There is good correlation between the trend of protein abundance levels in BALF and that of plasma which validates this approach to develop a blood biomarker to aid lung cancer diagnosis, particularly in the era of lung cancer screening. The protein signatures identified also provide insight into the molecular mechanisms associated with lung malignancy.

Prognostic value of cystatin C in patients with nasopharyngeal carcinoma: a retrospective study of 1063 patients

OBJECTIVE

Patients with nasopharyngeal carcinoma experience highly variable outcomes despite receiving similar therapeutic regimens. Identifying biomarkers that predict survival and guide individualized therapy is urgently needed. Cystatin C has been explored as a valuable prognostic marker in several malignancies. We retrospectively assessed the relationship between serum cystatin C levels and nasopharyngeal carcinoma prognosis in a large cohort of nasopharyngeal carcinoma patients receiving long-term follow-up.

METHODS

A total of 1063 consecutive patients diagnosed with nasopharyngeal carcinoma from June 2006 to December 2010 were retrospectively analyzed. The serum levels of cystatin C at the time of diagnosis were collected. Receiver operating characteristic curve analysis, the Kaplan-Meier method and multivariate analyses using a Cox regression model were performed to assess the correlation of cystatin C levels with overall survival, progression-free survival, distant metastasis-free survival and loco-regional recurrence-free survival.

RESULTS

The median follow-up duration was 68.3 months. The optimal cut-off value of cystatin C levels for predicting death was 0.945 mg/L. Compared with the low cystatin C group, the high cystatin C group experienced significantly shorter overall survival (hazard ratio=1.47, p=0.050), progression-free survival (hazard ratio=1.65, p=0.004), distant metastasis-free survival (hazard ratio=2.37, p<0.001) and loco-regional recurrence-free survival (hazard ratio=2.40, p=0.002). Based on multivariate analysis, a high cystatin C level was identified as a significant and independent negative predictor of overall survival (hazard ratio=1.47, p=0.050), progression-free survival (hazard ratio=1.65, p=0.004), distant metastasis-free survival (hazard ratio=2.37, p<0.001), and loco-regional recurrence-free survival (hazard ratio=2.40, p=0.002).

CONCLUSION

Cystatin C levels are associated with the prognosis of nasopharyngeal carcinoma patients. A high cystatin C level is an independent indicator of poor prognosis for nasopharyngeal carcinoma patients.

International Myeloma Working Group Recommendations for the Diagnosis and Management of Myeloma-Related Renal Impairment

Purpose

The aim of the International Myeloma Working Group was to develop practical recommendations for the diagnosis and management of multiple myeloma–related renal impairment (RI).

Methods

Recommendations were based on published data through December 2015, and were developed using the system developed by the Grading of Recommendation, Assessment, Development, and Evaluation Working Group.

Recommendations

All patients with myeloma at diagnosis and at disease assessment should have serum creatinine, estimated glomerular filtration rate, and electrolytes measurements as well as free light chain, if available, and urine electrophoresis of a sample from a 24-hour urine collection (grade A). The Chronic Kidney Disease Epidemiology Collaboration, preferably, or the Modification of Diet in Renal Disease formula should be used for the evaluation of estimated glomerular filtration rate in patients with stabilized serum creatinine (grade A). International Myeloma Working Group criteria for renal reversibility should be used (grade B). For the management of RI in patients with multiple myeloma, high fluid intake is indicated along with antimyeloma therapy (grade B). The use of high-cutoff hemodialysis membranes in combination with antimyeloma therapy can be considered (grade B). Bortezomib-based regimens remain the cornerstone of the management of myeloma-related RI (grade A). High-dose dexamethasone should be administered at least for the first month of therapy (grade B). Thalidomide is effective in patients with myeloma with RI, and no dose modifications are needed (grade B). Lenalidomide is effective and safe, mainly in patients with mild to moderate RI (grade B); for patients with severe RI or on dialysis, lenalidomide should be given with close monitoring for hematologic toxicity (grade B) with dose reduction as needed. High-dose therapy with autologous stem cell transplantation (with melphalan 100 mg/m2 to 140 mg/m2) is feasible in patients with RI (grade C). Carfilzomib can be safely administered to patients with creatinine clearance > 15 mL/min, whereas ixazomib in combination with lenalidomide and dexamethasone can be safely administered to patients with creatinine clearance > 30 mL/min (grade A).

Current Trends of Renal Impairment in Multiple Myeloma

BACKGROUND

Renal impairment (RI) is a common complication of multiple myeloma (MM). Around 50% of patients with MM have RI at presentation, and up to 5% require dialysis treatment. Severe acute kidney injury (AKI) as a cause of RI is a particular challenge as historically the survival of patients who sustain this complication and require dialysis is very poor. However, in this current period, survival is improving and the focus is on optimum use of novel chemotherapies and the evaluation of extra-corporeal therapies for removal of serum immunoglobulin light chains.

SUMMARY

RI in patients with MM is commonly associated with excess monoclonal free light chain (FLC) production; myeloma cast nephropathy is the predominant renal pathology in patients presenting with severe RI secondary to AKI. The majority of patients have mild to moderate RI and recover renal function. However, patients with more severe RI, in particular those with a requirement for dialysis, are less likely to recover renal function. Rapid diagnosis and prompt institution of anti-myeloma therapy is an important determinant of renal function recovery, through targeting early and sustained reduction of involved monoclonal FLC. Novel agents are associated with excellent disease response, and bortezomib is now widely used as a first-line agent in the management of MM in patients with severe RI. Extended haemodialysis using high cut-off dialysers is more effective for extracorporeal removal of FLC than plasma exchange, and clinical trials are in process. High-dose chemotherapy with autologous stem cell transplantation does have a role in patients with severe RI but requires careful patient selection.

KEY MESSAGES

RI is very common in patients with MM, and renal function recovery is associated with improved clinical outcomes. We summarise the epidemiology of MM in the UK, present the impact of RI and renal function recovery on patient outcome, and describe the current management of MM in western countries.

FACTS FROM EAST AND WEST

(1) A serum creatinine level >2 mg/dl has been reported in 16, 21, 24, and 33% of patients with MM in cohort studies from Japan, Europe, China, and Korea, respectively. A creatinine clearance rate <30 ml/min was observed in 30 and 15% of patients in Chinese and Western MM cohorts, respectively. The commonest cause of severe RI in patients with MM is myeloma cast nephropathy. (2) The efficacy of novel treatments (bortezomib, carfilzomib, thalidomide, and lenalidomide) has predominantly been assessed in Western patients. Bortezomib and dexamethasone are the current standard of care for MM and severe RI in the West. Severe RI is not a contraindication to autologous stem cell transplantation (ASCT). Most of the data are from the West; there are case reports from China describing good outcomes with ASCT. The removal of FLC by high-cut-off hemodialysis is under evaluation in randomized controlled trials (RCTs) in the West. Studies in this area are not yet conducted in China. In China, new treatments, such as bortezomib, are more widely used than before, and favorable results are being reported; however, RCT studies are still needed in this area to confirm the efficacy and safety of this and other novel treatments.

Bortezomib for the treatment of multiple myeloma

Bortezomib is the first proteasome inhibitor drug tested in human patients. Bortezomib demonstrates a particular clinical utility in the treatment of multiple myeloma (MM), where it is the only one of the new drugs administered as mono-therapy that prolongs survival. The significant problem for the consistent pursuit of bortezomib was neurotoxicity, which has been significantly reduced by registering subcutaneous administration or being administered once per week. Bortezomib is currently approved for the treatment of patients with progressive MM in mono-therapy and in combination with prednisone and melphalan in cases of untreated patients who are not candidates for autologous hematopoietic stem cell transplantation (AHSCT) and in combination with dexamethasone or dexamethasone and thalidomide in untreated MM patients, who are candidates for treatment AHSCT. Clinical research is focused on the combination of bortezomib with other new drugs with the hope of further optimizing the treatment of patients with multiple myeloma.

Optimizing the treatment of patients with multiple myeloma and renal impairment

Renal impairment is a common complication of multiple myeloma. It is found in about 20% to 25% of patients at diagnosis and in ≤ 50% at some point during the disease course. The presence of renal insufficiency diminishes patients' quality of life and has been associated with increased mortality, although the outcomes of patients after successful induction therapy have been comparable to those with normal renal function. Therefore, the treatment of patients with multiple myeloma and renal impairment is a major challenge and should aim to achieve remission in a large proportion of patients. New drugs introduced to treat multiple myeloma during the past decade have an established place in the treatment of patients with renal failure. Bortezomib appears to be most beneficial in this setting and, combined with other drugs, provides a chance for rapid remission and related improvement of renal function. Immunomodulatory drugs such as thalidomide and lenalidomide have also been used successfully in patients with renal insufficiency, although for the latter drug appropriate dose adjustments are necessary. The presence of renal failure is not a contraindication to autologous bone marrow transplantation in patients eligible for this procedure. Among the classic cytotoxic agents, bendamustine, in particular, should be considered for patients with renal insufficiency. Appropriate supportive care is also extremely important in the treatment of patients with multiple myeloma and renal failure. It can include plasmapheresis and removal of free light chains with high cut-off hemodialysis, adapted dosages of bisphosphonates, and avoidance of drugs and conditions that can impair renal function.

Case report on renal failure reversal in lambda chain multiple myeloma with bortezomib and dexamethasone

Renal failure (RF) reversal in multiple myeloma (MM) is associated with an improved prognosis. Light chain myeloma, serum creatinine (SCr) > 4 mg/dL, extensive proteinuria, early infections, and certain renal biopsy findings are associated with lower rates of RF reversal. Our patient is a 67-year-old female with multiple poor prognostic factors for RF reversal who demonstrated a rapid renal response with bortezomib and dexamethasone (BD) regimen. She presented initially with altered mental status. On exam, she appeared lethargic and dehydrated and had generalized tenderness. She had been taking ibuprofen as needed for pain for a few weeks. Labs showed a white cell count—18,900/μL with no bandemia, hemoglobin 10.8 gm/dL, potassium—6.7 mEq/L, bicarbonate—15 mEq/L, blood urea nitrogen—62 mg/dL, SCr—5.6 mg/dL (baseline: 1.10), and corrected calcium—11.8 mg/dL. A rapid flu test was positive. Imaging studies were unremarkable. Her EKG showed sinus tachycardia and her urinalysis was unremarkable. The unexplained RF in an elderly individual in conjunction with hypercalcemia and anemia prompted a MM work-up; eventually, lambda variant MM was diagnosed. An immediate (4 days) renal response defined as 50% reduction in SCr was noticed after initiation of the BD regimen.

Multiple myeloma international staging system: "staging" or simply "aging" system?

Because of the wide variation in multiple myeloma (MM) survival, numerous studies have focused over the past 40 years on the biological and cytogenetic prognostic values in MM patients. Since 2005, the MM International Staging System (ISS) has recognized the combination of beta-2 microglobulin (β2M) with serum albumin (SA) concentrations as the most simple and potent combination to determine the prognosis in MM patients. Curiously, the reasons for the efficiency of the combination of β2M with SA remain not clear-cut. In 2007, Fonseca and San Miguel (Prognostic factors and staging in multiple myeloma. Hematol Oncol Clin North Am 2007; 21:1115-40) underlined that cytogenetic assessment might also be useful for evaluating MM prognosis. Furthermore, new perspectives recently appeared with the genomic approach. Here, we (1) question the specific rationale for β2M and SA as prognostic markers in MM, (2) emphasize the well-documented prognostic implications of β2M and SA as potent biomarkers of comorbidity in older adults, and (3) conclude that the current MM-ISS is rather a staging system for age-related comorbidity burden (ie, aging system) than a specific MM staging system, and should not be used alone. Thus, we suggest that: (1) cytogenetics with the superscript MM-ISS could be the standard method; (2) some factors discovered using genomics could reflect the comorbidity burden and the intrinsic malignancy of MM clone, and thus needs more investigation; and (3) while waiting for standard genomic classification.

The Chronic Kidney Disease Epidemiology Collaboration cystatin C (CKD-EPI-CysC) equation has an independent prognostic value for overall survival in newly diagnosed patients with symptomatic multiple myeloma; is it time to change from MDRD to CKD-EPI-CysC equations?

OBJECTIVES

The estimation of glomerular filtration rate (eGFR) in multiple myeloma (MM) is based on equations that use serum creatinine (sCr), such as the Modification of Diet in Renal Disease (MDRD) equation. However, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) group has suggested that eGFR based on both sCr and cystatin C (CKD-EPI-sCr-CysC) is more accurate than other formulae for the estimation of kidney dysfunction. The aim of this study was to prospectively evaluate, for the first time in the literature, the CKD-EPI-sCR-CysC formula in newly diagnosed patients with symptomatic MM.

METHODS

We studied 220 newly diagnosed, previously untreated, patients with symptomatic myeloma and calculated eGFR using the MDRD, the CKD-EPI-sCR, the CKD-EPI-CysC, and the CKD-EPI-sCr-CysC equations.

RESULTS

CKD-EPI-sCr-CysC equation detected more myeloma patients with stage 3-5 renal impairment than the MDRD, CKD-EPI, or CKD-EPI-CysC equations: 45% vs. 39.5%, 42.2%, and 43.1%, respectively (P < 0.01). This was also observed in the elderly patients (>70 yrs), while in patients ≤70 yrs, the CKD-EPI-CysC equation managed to identify higher number of patients with stage 3-5 renal impairment (RI) than the other equations. Furthermore, 63 (28.6%) patients with eGFR values by the MDRD formula were reclassified to higher CKD stages according to CKD-EPI-CysC equation. The median overall survival for all patients was 52 months. In the multivariate analysis, that included International Staging System stage, lactate dehydrogenase (LDH) ≥300 U/L and eGFR for each different equation (as a continuous variable), only eGFR that included CysC, but not sCr had independent prognostic value (P = 0.013) along with high LDH (P = 0.029).

CONCLUSIONS

Our results suggest that equations based on CysC reveal higher number of MM patients with RI compared with equations based only in sCr. Furthermore, the CKD-EPI-CysC formula independently predicted for survival. Based on these data, we suggest that CKD-EPI equations based on CysC should substitute MDRD, as it has been suggested for patients with several other renal disorders.

Cystatin C and lactoferrin concentrations in biological fluids as possible prognostic factors in eye tumor development

Objectives

To investigate the possible role of cystatin C in eye biological fluids locally and in serum and lactoferrin revealing anti-tumor activity in eye tumor development.

Background

The increased number of eye tumors was registered recently not only in the countries with high insolation, but also in the northern countries including Russia (11 cases per million of population). Search for new biological markers is important for diagnosis and prognosis in eye tumors. Cystatin C, an endogenous inhibitor of cysteine proteases, plays an important protective role in several tumors. Lactoferrin was shown to express anti-tumor and antiviral activities. It was hypothesized that cystatin C and lactoferrin could serve as possible biomarkers in the diagnosis of malignant and benign eye tumors.

Study design

A total of 54 patients with choroidal melanoma and benign eye tumors were examined (part of them undergoing surgical treatment). Serum, tear fluid and intraocular fluid samples obtained from the anterior chamber of eyes in patients with choroidal melanoma were studied.

Methods

Cystatin C concentration in serum and eye biological fluids was measured by commercial ELISA kits for human (BioVendor, Czechia); lactoferrin concentration – by Lactoferrin-strip D 4106 ELISA test systems (Vector-BEST, Novosibirsk Region, Russia).

Results

Cystatin C concentration in serum of healthy persons was significantly higher as compared to tear and intraocular fluids. In patients with choroidal melanoma, increased cystatin C concentration was similar in tear fluid of both the eyes. Lactoferrin level in tear fluid of healthy persons was significantly higher than its serum level. Significantly increased lactoferrin concentration in tear fluid was noted in patients with benign and malignant eye tumors.

Conclusion

Increased level of cystatin C in tear fluid seems to be a possible diagnostic factor in the eye tumors studied. However, it does not allow us to differentiate between malignant and benign eye tumors. Similar changes were noted for lactoferrin in tear fluid.

Evaluation of serum procathepsin B, cystatin B and cystatin C as possible biomarkers of ovarian cancer

Objectives

To evaluate procathepsin B, as well as endogenous inhibitors of cysteine proteases (cystatin B and cystatin C) in biological fluids as possible biomarkers of ovarian cancer. To observe levels of serum procathepsin B in different age groups.

Study design

The sample (N=27) of women with gynaecological tumours included 18 patients with ovarian cancer (n=18) and 9 patients with benign ovarian tumours (n=9); 72 healthy women were in the control group. All patients were treated in Novosibirsk Regional Oncological Center, Russia. Serum samples of healthy women (n=40) aged 18–70 years were used as controls for common biomarker of ovarian cancer CA-125. In the Procathepsin B study, serum samples of healthy women (n=32) aged 18–40 years (n=14), 41–55 years (n=10) and 56–80 (n=8) years were used as controls.

Methods

Common biomarker of ovarian cancer, CA-125, was assayed by using a commercial kit (Vector, Koltsovo, Novosibirsk Region, Russia). Procathepsin B was measured by means of a commercial kit for human procathepsin B (R&D, USA); cystatin C was measured by commercial ELISA kits for human (BioVendor, Czechia); cystatin B was measured by ELISA kits for human (USCN Life Science Inc., Wuhan, China). Statistical analysis was performed by one-way ANOVA (Statistica 10 Program).

Results

In the control group, serum procathepsin B concentration did not reveal age dependency. In the ovarian cancer group, both levels of serum procathepsin B and standard biomarker CA-125 increased significantly (both p<0.001) compared with the control group. In the benign ovarian tumour group, serum procathepsin B (p<0.001) and CA-125 (p=0.004) increased about 2.5- and 8-fold compared to the control group. Serum cystatin B level increased up to 1.7-fold in the ovarian cancer group compared to the control group. The increase of serum CA-125 was about 3.5-fold higher (p=0.017) and procathepsin B was 1.8-fold higher (p<0.05) in the ovarian cancer group compared to the benign tumour group. Cystatin B in ascites fluid increased equally in both ovarian cancer (p<0.001) and benign ovarian tumours group (p<0.05). Cystatin C concentration in ascites fluid increased only in patients with ovarian cancer (p<0.05) and did not change in the benign tumours group. Large increases of procathepsin B level (about 13-fold, p<0.001) and to a lesser degree of cystatin C (1.8-fold, p<0.05) and cystatin B levels (1.4 fold, p<0.001) were revealed in ascites fluids of patients with ovarian cancer compared to the control serum.

The significant difference in serum procathepsin B levels was noted between the ovarian cancer and benign tumour groups (p<0.05), which could be used in differential diagnostics between malignant and benign gynaecological tumours.

Conclusion

Serum procathepsin B demonstrated significant promise as a new biomarker of ovarian cancer.

Bortezomib, dexamethasone plus thalidomide for treatment of newly diagnosed multiple myeloma patients with or without renal impairment

OBJECTIVE

To investigate the efficacy and safety of the treatment of the newly diagnosed multiple myeloma (MM) with or without renal impairment receiving the therapy of bortezomib, dexamethasone plus thalidomide (BTD) regimen in order to analyze the effects of BTD regimen on the prognosis of the MM patients with renal impairment compared with the patients without renal impairment.

METHODS

Seventy-two newly diagnosed MM patients entered into our study and all the patients belonged to International Stage System (ISS) 3 in which transplantation patients were excluded or the patients refused receiving transplantation therapy. According to the level of serum creatinine (Scr), the patients were divided into two groups including group 1 (n=42) (Scr <2 mg/dL) and group 2 (n=30) (Scr ≥2 mg/dL). All the patients received the therapy of BTD regimen as induction therapy, and the median treatment time was 5 (range, 2-8) cycles. The outcome was analyzed retrospectively.

RESULTS

The overall remission (OR) rates were 81.0% (group 1) and 80.0% (group 2). There was no statistical difference between the two groups (P>0.05). In group 2, 10 patients (33.3%) got renal function reversal, 14 patients (46.7%) got improved renal function and the median time to renal function reversal was 1.4 (range, 0.7-3.0) months. Among 12 patients with hemodialysis at diagnosis, 8 patients got rid of hemodialysis after median 4 cycles of therapy (range, 3-6 cycles). After a median follow-up period of 16 (range, 2-31) months, 5 patients (11.9%) in group 1 died and 9 patients (30.0%) in group 2 died (P=0.056). The 2-year estimate of overall survival was 77.3% in group 1 and 63.8% in group 2, respectively (P=0.188). During a median follow-up time of 13.0 months (range, 2-25 months), 15 patients (35.7%) in group 1 progressed and 13 patients (43.3%) in group 2 progressed (P=0.513). The 2-year estimate of response duration was 50.6% in group 1 and 42.1% in group 2, respectively (P=1). The main toxicities in the two groups included thrombocytopenia, peripheral neuropathy (PN), infection, herpes zoster and so on. The incidence of grade 3 and 4 adverse events was low.

CONCLUSIONS

BTD regimen may become the front-line therapy for the newly diagnosed MM patients with renal impairment because BTD regimen can improve the prognosis of the patients with renal impairment as good as the patients without renal impairment.

Management of myeloma-associated renal dysfunction in the era of novel therapies

Multiple myeloma (MM) is a plasma cell neoplasm often associated with renal impairment (RI), with myeloma cast nephropathy recognized as the most common cause. While RI is present in over 50% of MM patients at some point in their disease course, it is associated with higher tumor burden, more aggressive disease, diminished quality of life, development of complications and increased mortality. The introduction of novel therapies, including bortezomib, lenalidomide and thalidomide, has revolutionized the management of MM. They are now considered first-line therapies in induction, maintenance and salvage therapy for MM. In addition to their anti-MM effect, they can improve outcome in patients with RI, especially when combined, and bortezomib with dexamethasone may have a renal protective effect. This review focuses on the use of these agents in patients with MM and RI, and evaluates their efficacy, safety, need for dose adjustment and impact on RI.

Prognostic significance of serum cystatin C in multiple myeloma

Multiple myeloma (MM) is frequently complicated by renal insufficiency, which is associated with an unfavorable prognosis. Serum cystatin C is a new and accurate marker of glomerular filtration rate. Global gene expression analysis has revealed serum cystatin C as one of the most highly upregulated genes in MM. Recent data have shown serum cystatin C as an independent prognostic marker in MM. To further elucidate the prognostic significance of serum cystatin C, we investigated pretreatment serum cystatin C levels in 68 newly diagnosed patients homogeneously treated with high-dose melphalan followed by autologous stem cell transplantation. Median serum cystatin C level in MM patients was significantly higher than in the 66 healthy controls (1.07 vs. 0.74 mg/L [p = 0.002]). Median serum cystatin C levels significantly increased with higher International Staging System (ISS) stages (stage I 0.72 mg/L; stage II 0.89 mg/L; stage III 1.28 mg/L; p < 0.0001). Higher serum cystatin C was positively correlated with higher serum levels of creatinine (r = 0.84; p < 0.0001), β2-microglobulin (r = 0.72; p < 0.0001), LDH (r = 0.43; p = 0.0003), white blood cell counts (r = 0.61; p < 0.0001) and calcium (r = 0.29; p = 0.016), and negatively correlated with lower serum albumin levels (r = 0.44; p < 0.0001) and hemoglobin levels (r = 0.31; p = 0.01). Using ROC analysis, patients with serum cystatin C levels ≥0.95 mg/L (n = 24) had a significantly shorter event-free survival (EFS) and overall survival (OS) than patients with serum cystatin C levels <0.95 mg/L (median EFS: 26 vs. 44 months, p < 0.0001; median OS: 54 vs. 68 months, p = 0.05). Moreover, the combination of serum cystatin C level and genomic aberrations further refined the prognostic information (EFS and OS) provided by either one of the factors. The level of serum cystatin C is not only a sensitive marker of renal function, but also reflects tumor burden and delivers prognostic information in MM.

Novel therapeutic agents for the management of patients with multiple myeloma and renal impairment

Renal impairment is a major complication of multiple myeloma. Patients presenting with severe renal impairment represent a greater therapeutic challenge and generally have poorer outcome. However, once patients with renal impairment achieve remission, their outcomes are comparable with those of patients without renal impairment. Therapies that offer substantial activity in this setting are needed. Bortezomib, thalidomide, and lenalidomide have substantially improved the survival of patients with multiple myeloma. Here we review the pharmacokinetics, activity, and safety of these agents in patients with renal impairment. Bortezomib can be administered at the full approved dose and schedule in renally impaired patients; similarly, no dose reductions are required with thalidomide. The pharmacokinetics of lenalidomide is affected by its renal route of excretion, and dose adjustments are recommended for moderate/severe impairment. Substantial evidence has emerged showing that these novel agents improve outcomes of patients with renal impairment, including impairment reversal. Bortezomib, thalidomide, and lenalidomide (at the recommended doses) are active options for patients with mild to moderate impairment, although limited data are available for thalidomide. Information on lenalidomide-based combinations is still emerging, but the available data indicate considerable activity. Substantial evidence indicates that bortezomib-high-dose dexamethasone with or without a third drug (e.g., cyclophosphamide, thalidomide, or doxorubicin) is an appropriate option for patients with any degree of renal impairment.

Safety and efficacy of bortezomib-melphalan-prednisone-thalidomide followed by bortezomib-thalidomide maintenance (VMPT-VT) versus bortezomib-melphalan-prednisone (VMP) in untreated multiple myeloma patients with renal impairment

We assessed efficacy, safety, and reversal of renal impairment (RI) in untreated patients with multiple myeloma given bortezomib-melphalan-prednisone-thalidomide followed by bortezomib-thalidomide (VMPT-VT) maintenance or bortezomib-melphalan-prednisone (VMP). Exclusion criteria included serum creatinine ≥ 2.5 mg/dL. In the VMPT-VT/VMP arms, severe RI (estimated glomerular filtration rate [eGFR] ≤ 30 mL/min), moderate RI (eGFR 31-50 mL/min), and normal renal function (eGFR > 50 mL/min), were 6%/7.9%, 24.1%/24.9%, and 69.8%/67.2%, respectively. Statistically significant improvements in overall response rates and progression-free survival were observed in VMPT-VT versus VMP arms across renal cohorts, except in severe RI patients. In the VMPT group, severe RI reduced overall survival (OS). RI was reversed in 16/63 (25.4%) patients receiving VMPT-VT versus 31/77 (40.3%) receiving VMP. Multivariate analysis showed male sex (P = .022) and moderate RI (P = .003) significantly predicted RI recovery. VMP patients achieving renal response showed longer OS. In both arms, greater rates of severe hematologic adverse events were associated with RI (eGFR < 50 mL/min), however, therapy discontinuation rates were unaffected. VMPT-VT was superior to VMP for cases with normal renal function and moderate RI, whereas VMPT-VT failed to outperform VMP in patients with severe RI, although the relatively low number of cases analyzed preclude drawing definitive conclusions. VMPT-VT had no advantage in terms of RI reversal over VMP. This study is registered at http://www.clinicaltrials.gov as NCT01063179.

Consensus on the utility of bone markers in the malignant bone disease setting

Biochemical markers of bone turnover provide insight into ongoing rates of skeletal metabolism and tumor-bone interactions in patients with malignant bone disease. This article reviews the available recent evidence assessing the potential of bone markers for detecting and monitoring malignant bone lesions in patients with advanced cancers, and for assessing overall skeletal health and response to antiresorptive therapies in patients at all stages of cancer progression. Most data thus far are for urinary N-terminal cross-linked telopeptide of type I collagen (NTX) in predicting risks of skeletal morbidity and death and monitoring response to zoledronic acid in patients with bone metastases. Ongoing studies are evaluating such correlations for other markers and therapies. Emerging evidence suggests that bone markers may help identify patients at high risk for bone metastasis or bone lesion progression, thereby allowing improved follow-up. Results from ongoing clinical trials evaluating such potential applications of bone markers are awaited.

Monitoring bortezomib therapy in multiple myeloma: screening of cyclin D1, D2, and D3 via reliable real-time polymerase chain reaction and association with clinico-pathological features and outcome

Cyclins D1, D2, and D3 (CCND1, 2, 3) are regulated by proteasomal degradation. Their overexpression in multiple myeloma (MM) has prognostic value. We performed this pilot study to analyze a possible association between CCND1-3 overexpression and response to treatment with the proteasome inhibitor bortezomib, since a specific prognostic marker for bortezomib response has not been reported, but would be ideal to predict who benefits most from bortezomib in times of several potentially efficient therapeutic options. Bone marrow (BM) specimens of 20/47 consecutive patients were available for reliable CCND1-3 analyses by real-time PCR. With CCND1 overexpression in 9/20 patients, the risk for progression after bortezomib treatment was significantly decreased (HR 0.102, 95% CI 0.021-0.498, p = 0.0048) and progression-free survival substantially prolonged (p = 0.0011). Our study is the first to suggest that overexpressed CCND1 in MM is an independent prognostic marker associated with a more durable response to bortezomib. These preliminary results warrant a larger study.

Renal Insufficiency and Failure

Renal impairment is a common complication of multiple myeloma. Chronic renal failure is classified according to glomerular filtration rate as estimated by the MDRD (modification of diet in renal disease) formula, while RIFLE (risk, injury, failure, loss and end-stage renal disease) and AKIN (acute renal injury network) criteria may be used for the definition of the severity of acute renal injury. Novel criteria based on estimated glomerular filtration rate measurements are proposed for the definition of the reversibility of renal impairment. Renal complete response (CRrenal) is defined as sustained (i.e., lasting at least 2 months) improvement of creatinine clearance (CRCL) from under 50 mL/min at baseline to 60 mL/min or above. Renal partial response (PRrenal) is defined as sustained improvement of CRCL from under 15 mL/min at baseline to 30 to 59 mL/min. Renal minor response (MRrenal) is defined as sustained improvement of the baseline CRCL of under 15 mL/min to 15 to 29 mL/min or, if baseline CRCL was 15 to 29 mL/min, improvement to 30 to 59 mL/min. Bortezomib with high-dose dexamethasone is considered the treatment of choice for myeloma patients with renal impairment and improves renal function in most patients. Although there is limited experience with thalidomide, this agent can be administered at the standard dosage to patients with renal failure. Lenalidomide, when administered at reduced doses according to renal function, is effective and can reverse renal impairment in a subset of myeloma patients.

Renal Impairment in Patients With Multiple Myeloma: A Consensus Statement on Behalf of the International Myeloma Working Group

Renal impairment is a common complication of multiple myeloma (MM). The estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease formula is the recommended method for the assessment of renal function in patients with MM with stabilized serum creatinine. In acute renal injury, the RIFLE (risk, injury, failure, loss and end-stage kidney disease) and Acute Renal Injury Network criteria seem to be appropriate to define the severity of renal impairment. Novel criteria based on eGFR measurements are recommended for the definition of the reversibility of renal impairment. Rapid intervention to reverse renal dysfunction is critical for the management of these patients, especially for those with light chain cast nephropathy. Bortezomib with high-dose dexamethasone is considered as the treatment of choice for such patients. There is limited experience with thalidomide in patients with myeloma with renal impairment. Thus, thalidomide can be carefully administered, mainly in the context of well-designed clinical trials, to evaluate if it can improve the rapidity and probability of response that is produced by the combination with bortezomib and high-dose dexamethasone. Lenalidomide is effective in this setting and can reverse renal insufficiency in a significant subset of patients, when it is given at reduced doses, according to renal function. The role of plasma exchange in patients with suspected light chain cast nephropathy and renal impairment is controversial. High-dose melphalan (140 mg/m2) and autologous stem-cell transplantation should be limited to younger patients with chemosensitive disease.

Confident assignment of intact mass tags to human salivary cystatins using top-down Fourier-transform ion cyclotron resonance mass spectrometry

A hybrid linear ion-trap Fourier-transform ion cyclotron resonance mass spectrometer was used for top-down characterization of the abundant human salivary cystatins, including S, S1, S2, SA, SN, C, and D, using collisionally activated dissociation (CAD) after chromatographic purification of the native, disulfide intact proteins. Post-translational modifications and protein sequence polymorphisms arising from single nucleotide polymorphisms (SNPs) were assigned from precursor and product ion masses at a tolerance of 10 ppm, allowing confident identification of individual intact mass tags. Cystatins S, S1, S2, SA, and SN were cleaved of a N-terminal 20 amino acid signal peptide and cystatin C a 26-residue peptide, to yield a generally conserved N-terminus. In contrast, cystatin D isoforms with 24 and 28 amino acid residue N-terminal truncations were found such that their N-termini were not conserved. Cystatin S1 was phosphorylated at Ser3, while S2 was phosphorylated at Ser1 and Ser3, in agreement with previous work. Both cystatin D isoforms carried the polymorphism C46R (SNP: rs1799841). The 14,328 Da isoform of cystatin SN previously assigned with polymorphism P31L due to a SNP (rs2070856) was found only in whole saliva. Parotid secretions contained no detectable cystatins while whole saliva largely mirrored the contents of submandibular/sublingual (SMSL) secretions. With fully characterized cystatin intact mass tags it will now be possible to examine the correlation between the abundance of these molecules and human health and disease.

Reversibility of renal failure in newly diagnosed patients with multiple myeloma and the role of novel agents

The purpose of this analysis was to assess the effect of novel agent-based regimens on the improvement of renal impairment (RI) in newly diagnosed patients with multiple myeloma. Ninety-six consecutive patients with RI received conventional chemotherapy (CC)-based regimens (n=32), IMiDs-based regimens (n=47) or bortezomib-based regimens (n=17) as frontline therapy. Improvement of RI was more frequent in patients treated with novel agents (79% in IMiD- and 94% in bortezomib-treated groups versus 59% in CC-treated group; p=0.02). Bortezomib-based regimens and CrCl>30 ml/min at baseline independently correlated with a higher probability of at least renal partial response (PRrenal) and with a shorter time to PRrenal or better. Thus bortezomib-based regimens may be the preferred treatment for newly diagnosed myeloma patients with RI.