Statin use is associated with improved survival in multiple myeloma: A Swedish population-based study of 4315 patients

Discovering Potential in Non-Cancer Medications: A Promising Breakthrough for Multiple Myeloma Patients

MM is a common type of cancer that unfortunately leads to a significant number of deaths each year. The majority of the reported MM cases are detected in the advanced stages, posing significant challenges for treatment. Additionally, all MM patients eventually develop resistance or experience relapse; therefore, advances in treatment are needed. However, developing new anti-cancer drugs, especially for MM, requires significant financial investment and a lengthy development process. The study of drug repurposing involves exploring the potential of existing drugs for new therapeutic uses. This can significantly reduce both time and costs, which are typically a major concern for MM patients. The utilization of pre-existing non-cancer drugs for various myeloma treatments presents a highly efficient and cost-effective strategy, considering their prior preclinical and clinical development. The drugs have shown promising potential in targeting key pathways associated with MM progression and resistance. Thalidomide exemplifies the success that can be achieved through this strategy. This review delves into the current trends, the challenges faced by conventional therapies for MM, and the importance of repurposing drugs for MM. This review highlights a noncomprehensive list of conventional therapies that have potentially significant anti-myeloma properties and anti-neoplastic effects. Additionally, we offer valuable insights into the resources that can help streamline and accelerate drug repurposing efforts in the field of MM.

Unraveling lipid metabolism reprogramming for overcoming drug resistance in melanoma

Cutaneous melanoma is the deadliest form of skin cancer, and its incidence is continuing to increase worldwide in the last decades. Traditional therapies for melanoma can easily cause drug resistance, thus the treatment of melanoma remains a challenge. Various studies have focused on reversing the drug resistance. As tumors grow and progress, cancer cells face a constantly changing microenvironment made up of different nutrients, metabolites, and cell types. Multiple studies have shown that metabolic reprogramming of cancer is not static, but a highly dynamic process. There is a growing interest in exploring the relationship between melanoma andmetabolic reprogramming, one of which may belipid metabolism. This review frames the recent research progresses on lipid metabolism in melanoma.In addition, we emphasize the dynamic ability of metabolism during tumorigenesis as a target for improving response to different therapies and for overcoming drug resistance in melanoma.

DHCR24 in Tumor Diagnosis and Treatment: A Comprehensive Review

As an important nutrient in the human body, cholesterol can not only provide structural components for the body's cells, but also can be transformed into a variety of active substances to regulate cell signaling pathways. As an important cholesterol synthase, DHCR24 participates in important regulatory processes in the body. The application of DHCR24 in tumor clinical diagnosis and treatment also attracts much attention. This article reviews the structure and regulatory characteristics of DHCR24, and the research of DHCR24 on tumor progression. We summarize the possible mechanisms of DHCR24 promoting tumor progression through reactive oxygen species (ROS), p53, Ras and PI3K-AKT pathways. Through our review, we hope to provide more research ideas and reference value for the application of DHCR24 in tumor prevention and treatment.

Low cholesterol levels are associated with increasing risk of plasma cell neoplasm: A UK biobank cohort study

BACKGROUND

Plasma cell neoplasms are a group of hematologic neoplasms that often develop in the elderly population. The relationship between cholesterol levels and hematologic malignancy has been identified in population studies. However, it is still unclear if there is a relationship between cholesterol levels and plasma cell neoplasm in European ancestry.

METHODS

Prospective cohorts included 502,507 individuals from the UK Biobank who were followed up to 2019 and assessed total cholesterol(TC) levels, low-density lipoprotein (LDL) levels, high-density lipoprotein (HDL) levels, apolipoprotein A (ApoA) and apolipoprotein B (ApoB) as risk factors for plasma cell neoplasms with Cox proportional hazard regression and restricted cubic spline model. We also used two-sample Mendelian randomization to determine if the cholesterol level has a causal effect on developing plasma cell neoplasms.

RESULTS

We observed 1819 plasma cell neoplasm cases during 14.2 years of follow-up in the UK Biobank. We found higher blood serum cholesterol levels at baseline were associated with a lower risk of plasma cell neoplasm in our study. All lipid profiles we analyzed in this study were inversely associated with plasma cell neoplasm risk (all ptrend  <0.005) but triglycerides did not have such association. However, there was no suggestive association of genetically predicted serum LDL, HDL, and total cholesterol levels with multiple myeloma.

CONCLUSION

Low serum total cholesterol, LDL, HDL, ApoA, and ApoB levels were all associated with increasing the risk of plasma cell neoplasm.

Sex differences in FASN protein concentrations in urinary exosomes related to serum triglycerides levels in healthy adults

BACKGROUND

Dysregulation of lipid metabolism is the most prominent metabolic alteration observed in obesity, cancer, and cardiovascular diseases. The present study aimed to explore the sex differences associated with lipid metabolism in urinary exosome proteins, and evaluate the correlation of urinary exosome proteins with serum lipid biomarkers.

METHODS

The key enzymes regulating lipid metabolism in healthy adults were screened using urinary exosome data. Urinary exosomes were isolated from 120 healthy subjects and the expression of urinary proteins was assessed by Western blotting and ELISA. The correlation between urinary protein concentrations and the levels of serum lipid biomarkers was analyzed using correlation analysis.

RESULTS

Three urinary exosome proteins, namely fatty acid synthase (FASN), phosphoenolpyruvate carboxykinase (PCK1), and ATP-citrate synthase (ACLY) were identified, and only FASN showed sex differences. Sex differences were also observed in the serum triglyceride (TG) levels. Healthy males had higher FASN levels than females, and a moderate positive correlation was found between FASN concentrations and serum TG levels in healthy males (r = 0.479, P < 0.05). FASN concentrations in different age groups were positively correlated with the level of serum TG (18 ~ 30 years, r = 0.502; 31 ~ 44 years, r = 0.587; 45 ~ 59 years, r = 0.654; all P < 0.05). In addition, FASN concentrations was positively related to the increase in serum TG levels (range:1.0 ~ 1.7 mmol/L; r = 0.574, P < 0.05).

CONCLUSIONS

Sex differences were observed in urinary exosome FASN protein levels in healthy adults. FASN protein levels positively correlated with increased serum TG levels. FASN may serve as a novel biomarker to evaluate fatty acid synthesis in the human body.

Functional significance of cholesterol metabolism in cancer: from threat to treatment

Cholesterol is an essential structural component of membranes that contributes to membrane integrity and fluidity. Cholesterol homeostasis plays a critical role in the maintenance of cellular activities. Recently, increasing evidence has indicated that cholesterol is a major determinant by modulating cell signaling events governing the hallmarks of cancer. Numerous studies have shown the functional significance of cholesterol metabolism in tumorigenesis, cancer progression and metastasis through its regulatory effects on the immune response, ferroptosis, autophagy, cell stemness, and the DNA damage response. Here, we summarize recent literature describing cholesterol metabolism in cancer cells, including the cholesterol metabolism pathways and the mutual regulatory mechanisms involved in cancer progression and cholesterol metabolism. We also discuss various drugs targeting cholesterol metabolism to suggest new strategies for cancer treatment.

Proteomic and Metabolomic Analysis of Bone Marrow and Plasma from Patients with Extramedullary Multiple Myeloma Identifies Distinct Protein and Metabolite Signatures

Multiple myeloma (MM) is an incurable haematological malignancy of plasma cells in the bone marrow. In rare cases, an aggressive form of MM called extramedullary multiple myeloma (EMM) develops, where myeloma cells enter the bloodstream and colonise distal organs or soft tissues. This variant is associated with refractoriness to conventional therapies and a short overall survival. The molecular mechanisms associated with EMM are not yet fully understood. Here, we analysed the proteome of bone marrow mononuclear cells and blood plasma from eight patients (one serial sample) with EMM and eight patients without extramedullary spread. The patients with EMM had a significantly reduced overall survival with a median survival of 19 months. Label-free mass spectrometry revealed 225 proteins with a significant differential abundance between bone marrow mononuclear cells (BMNCs) isolated from patients with MM and EMM. This plasma proteomics analysis identified 22 proteins with a significant differential abundance. Three proteins, namely vascular cell adhesion molecule 1 (VCAM1), pigment epithelium derived factor (PEDF), and hepatocyte growth factor activator (HGFA), were verified as the promising markers of EMM, with the combined protein panel showing excellent accuracy in distinguishing EMM patients from MM patients. Metabolomic analysis revealed a distinct metabolite signature in EMM patient plasma compared to MM patient plasma. The results provide much needed insight into the phenotypic profile of EMM and in identifying promising plasma-derived markers of EMM that may inform novel drug development strategies.

Artificial intelligence-enabled screening strategy for drug repurposing in monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is a benign hematological condition with the potential to progress to malignant conditions including multiple myeloma and Waldenstrom macroglobulinemia. Medications that modify progression risk have yet to be identified. To investigate, we leveraged machine-learning and electronic health record (EHR) data to screen for drug repurposing candidates. We extracted clinical and laboratory data from a manually curated MGUS database, containing 16,752 MGUS patients diagnosed from January 1, 2000 through December 31, 2021, prospectively maintained at Mayo Clinic. We merged this with comorbidity and medication data from the EHR. Medications were mapped to 21 drug classes of interest. The XGBoost module was then used to train a primary Cox survival model; sensitivity analyses were also performed limiting the study group to those with non-IgM MGUS and those with M-spikes >0.3 g/dl. The impact of explanatory features was quantified as hazard ratios after generating distributions using bootstrapping. Medication data were available for 12,253 patients; those without medications data were excluded. Our model achieved a good fit of the data with inverse probability of censoring weights concordance index of 0.883. The presence of multivitamins, immunosuppression, non-coronary NSAIDS, proton pump inhibitors, vitamin D supplementation, opioids, statins and beta-blockers were associated with significantly lower hazard ratio for MGUS progression in our primary model; multivitamins and non-coronary NSAIDs remained significant across both sensitivity analyses. This work could inform subsequent prospective studies, or similar studies in other disease states.

Metabolic switch in cancer - Survival of the fittest

Cell metabolism is characterised by the highly coordinated conversion of nutrients into energy and biomass. In solid cancers, hypoxia, nutrient deficiencies, and tumour vasculature are incompatible with accelerated anabolic growth and require a rewiring of cancer cell metabolism. Driver gene mutations direct malignant cells away from oxidation to maximise energy production and biosynthesis while tumour-secreted factors degrade peripheral tissues to fuel disease progression and initiate metastasis. As it is vital to understand cancer cell metabolism and survival mechanisms, this review discusses the metabolic switch and current drug targets and clinical trials. In the future, metabolic markers may be included when phenotyping individual tumours to improve the therapeutic opportunities for personalised therapy.

Targeting the Isoprenoid Biosynthetic Pathway in Multiple Myeloma

Multiple myeloma (MM) is a plasma cell malignancy for which there is currently no cure. While treatment options for MM have expanded over the last two decades, all patients will eventually become resistant to current therapies. Thus, there is an urgent need for novel therapeutic strategies to treat MM. The isoprenoid biosynthetic pathway (IBP) is responsible for the post-translational modification of proteins belonging to the Ras small GTPase superfamily, such as Ras, Rho and Rab family members. Given the important roles these GTPase proteins play in various cellular processes, there is significant interest in the development of inhibitors that disturb their prenylation and consequently their activity in MM cells. Numerous preclinical studies have demonstrated that IBP inhibitors have anti-MM effects, including the induction of apoptosis in MM cells and inhibition of osteoclast activity. Some IBP inhibitors have made their way into the clinic. For instance, nitrogenous bisphosphonates are routinely prescribed for the management MM bone disease. Other IBP inhibitors, including statins and farnesyltransferase inhibitors, have been evaluated in clinical trials for MM, while there is substantial preclinical investigation into geranylgeranyl diphosphate synthase inhibitors. Here we discuss recent advances in the development of IBP inhibitors, assess their mechanism of action and evaluate their potential as anti-MM agents.

Genetic Alterations and Deregulation of Hippo Pathway as a Pathogenetic Mechanism in Bone and Soft Tissue Sarcoma

The Hippo pathway is an evolutionarily conserved modulator of developmental biology with a key role in tissue and organ size regulation under homeostatic conditions. Like other signaling pathways with a significant role in embryonic development, the deregulation of Hippo signaling contributes to oncogenesis. Central to the Hippo pathway is a conserved cascade of adaptor proteins and inhibitory kinases that converge and regulate the activity of the oncoproteins YAP and TAZ, the final transducers of the pathway. Elevated levels and aberrant activation of YAP and TAZ have been described in many cancers. Though most of the studies describe their pervasive activation in epithelial neoplasms, there is increasing evidence pointing out its relevance in mesenchymal malignancies as well. Interestingly, somatic or germline mutations in genes of the Hippo pathway are scarce compared to other signaling pathways that are frequently disrupted in cancer. However, in the case of sarcomas, several examples of genetic alteration of Hippo members, including gene fusions, have been described during the last few years. Here, we review the current knowledge of Hippo pathway implication in sarcoma, describing mechanistic hints recently reported in specific histological entities and how these alterations represent an opportunity for targeted therapy in this heterogeneous group of neoplasm.

Immunometabolism in the tumor microenvironment and its related research progress

The tumor immune microenvironment has been a research hot spot in recent years. The cytokines and metabolites in the microenvironment can promote the occurrence and development of tumor in various ways and help tumor cells get rid of the surveillance of the immune system and complete immune escape. Many studies have shown that the existence of tumor microenvironment is an important reason for the failure of immunotherapy. The impact of the tumor microenvironment on tumor is a systematic study. The current research on this aspect may be only the tip of the iceberg, and a relative lack of integrity, may be related to the heterogeneity of tumor. This review mainly discusses the current status of glucose metabolism and lipid metabolism in the tumor microenvironment, including the phenotype of glucose metabolism and lipid metabolism in the microenvironment; the effects of these metabolic methods and their metabolites on three important immune cells Impact: regulatory T cells (Tregs), tumor-associated macrophages (TAM), natural killer cells (NK cells); and the impact of metabolism in the targeted microenvironment on immunotherapy. At the end of this article,the potential relationship between Ferroptosis and the tumor microenvironment in recent years is also briefly described.

Lipoproteins and cancer: The role of HDL-C, LDL-C, and cholesterol-lowering drugs

Cholesterol is an amphipathic sterol molecule that is vital for maintaining normal physiological homeostasis. It is a relatively complicated molecule with 27 carbons whose synthesis starts with 2-carbon units. This in itself signifies the importance of this molecule. Cholesterol serves as a precursor for vitamin D, bile acids, and hormones, including estrogens, androgens, progestogens, and corticosteroids. Although essential, high cholesterol levels are associated with cardiovascular and kidney diseases and cancer initiation, progression, and metastasis. Although there are some contrary reports, current literature suggests a positive association between serum cholesterol levels and the risk and extent of cancer development. In this review, we first present a brief overview of cholesterol biosynthesis and its transport, then elucidate the role of cholesterol in the progression of some cancers. Suggested mechanisms for cholesterol-mediated cancer progression are plentiful and include the activation of oncogenic signaling pathways and the induction of oxidative stress, among others. The specific roles of the lipoprotein molecules, high-density lipoprotein (HDL) and low-density lipoprotein (LDL), in this pathogenesis, are also reviewed. Finally, we hone on the potential role of some cholesterol-lowering medications in cancer.

Optimising cardiovascular care of patients with multiple myeloma

Multiple myeloma (MM) is the third most common haematological malignancy, with increasing prevalence over recent years. Advances in therapy have improved survival, changing the clinical course of MM into a chronic condition and meaning that management of comorbidities is fundamental to improve clinical outcomes. Cardiovascular (CV) events affect up to 7.5% of individuals with MM, due to a combination of patient, disease and treatment-related factors and adversely impact survival. MM typically affects older people, many with pre-existing CV risk factors or established CV disease, and the disease itself can cause renal impairment, anaemia and hyperviscosity, which exacerabate these further. Up to 15% of patients with MM develop systemic amyloidosis, with prognosis determined by the extent of cardiac involvement. Management of MM generally involves administration of multiple treatment lines over several years as disease progresses, with many drug classes associated with adverse CV effects including high rates of venous and arterial thrombosis alongside heart failure. Recommendations for holistic management of patients with MM now include routine baseline risk stratification including ECG and echocardiography and administration of thromboprophylaxis drugs for patients treated with immunomodulatory drugs. Close surveillance of high-risk patients with collaboration between haematology and cardiology is required, with prompt investigation in the event of CV symptoms, in order to identify and treat complications early. Decisions regarding discontinuation of cardiotoxic therapies should be made in a multidisciplinary setting, taking into account the severity of the complication, prognosis, expected benefits and the availability of effective alternatives.

Lipid metabolism and cancer

Dysregulation in lipid metabolism is among the most prominent metabolic alterations in cancer. Cancer cells harness lipid metabolism to obtain energy, components for biological membranes, and signaling molecules needed for proliferation, survival, invasion, metastasis, and response to the tumor microenvironment impact and cancer therapy. Here, we summarize and discuss current knowledge about the advances made in understanding the regulation of lipid metabolism in cancer cells and introduce different approaches that have been clinically used to disrupt lipid metabolism in cancer therapy.

Statin use and survival in 16 098 patients with non-Hodgkin lymphoma or chronic lymphocytic leukaemia treated in the rituximab era

Statin use has been associated with reduced mortality from several cancers but also suggested, in vitro, to diminish the effectiveness of lymphoma treatments including rituximab. The present study aimed to assess the association of statin use with mortality in patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukaemia (CLL). We identified all incident NHLs and CLLs in Sweden from 2007 to 2013 with subtype information in the Swedish Lymphoma and Cancer Registers. Using Cox regression, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of pre- or post-diagnosis statin use (yes/no, intensity) with lymphoma-specific, cardiovascular, or all-cause mortality; and for follicular lymphoma (FL) by initial treatment strategy (active/watch-and-wait). Among 16 098 incident NHL/CLL patients, 20% used statins at diagnosis. Pre- and post-diagnosis statin use, and statin intensity were not consistently associated with any mortality outcome in patients with NHL, overall or for any subtype. For actively treated patients with FL, statin use did not appear to increase lymphoma-specific mortality (vs. non-users, HR [95% CI]_{after diagnosis} 0·87 [0·45-1·67]). For CLL, statin use was associated with all-cause and cardiovascular but not consistently with lymphoma-specific mortality. In conclusion, statin use was not associated with improved lymphoma survival but appears safe to use during lymphoma treatment.

Cholesterol Metabolic Reprogramming in Cancer and Its Pharmacological Modulation as Therapeutic Strategy

Cholesterol is a ubiquitous sterol with many biological functions, which are crucial for proper cellular signaling and physiology. Indeed, cholesterol is essential in maintaining membrane physical properties, while its metabolism is involved in bile acid production and steroid hormone biosynthesis. Additionally, isoprenoids metabolites of the mevalonate pathway support protein-prenylation and dolichol, ubiquinone and the heme a biosynthesis. Cancer cells rely on cholesterol to satisfy their increased nutrient demands and to support their uncontrolled growth, thus promoting tumor development and progression. Indeed, transformed cells reprogram cholesterol metabolism either by increasing its uptake and de novo biosynthesis, or deregulating the efflux. Alternatively, tumor can efficiently accumulate cholesterol into lipid droplets and deeply modify the activity of key cholesterol homeostasis regulators. In light of these considerations, altered pathways of cholesterol metabolism might represent intriguing pharmacological targets for the development of exploitable strategies in the context of cancer therapy. Thus, this work aims to discuss the emerging evidence of in vitro and in vivo studies, as well as clinical trials, on the role of cholesterol pathways in the treatment of cancer, starting from already available cholesterol-lowering drugs (statins or fibrates), and moving towards novel potential pharmacological inhibitors or selective target modulators.

Association between statin use and second cancer risk in breast cancer patients: a nationwide population-based cohort study

PURPOSE

Many studies have revealed that statin therapy reduced mortality in cancer patients, especially in breast cancer, but the effect for second cancer was unclear. We, therefore, performed a comparable cohort study to determine the risk of second cancer in breast cancer patients with statin therapy.

METHODS

Using claims data from Taiwan's National Health Insurance Program, this study enrolled newly diagnosed breast cancer patients from 2000 to 2007 with and without statin therapy as the statin (n = 1222) and nonstatin (n = 4888) cohorts, respectively. The nonstatin cohort was propensity score matched by cohort entry year, age, and randomly selected comorbidities. These two cohorts were followed up until the diagnosis of second cancer, death, or the end of 2011. Cox proportional hazard models were used to estimate the hazard ratios.

RESULTS

The statin cohort had a lower incidence rate than the nonstatin cohort for second cancer (7.37 vs. 8.36 per 1000 person-years), although the difference was not significant (adjusted hazard ratio [aHR] 0.90, 95% confidence interval [CI] 0.65-1.26). Compared with the nonstatin cohort, the second cancer risk was significantly higher for patients taking pravastatin (aHR 2.71, 95% CI 1.19-6.19) but lower for those receiving multiple statin treatment (aHR 0.45, 95% CI 0.25-0.81) and combined lipophilic and hydrophilic type of statin (aHR 0.42, 95% CI 0.20-0.89). The risk was lower for patients receiving a cumulative defined daily dose (cDDD) of > 430 (aHR 0.41, 95% CI 0.19-0.86).

CONCLUSION

This study showed that there is little association between statin use and second cancer risk in breast cancer patients.

Statins Reduce Mortality in Multiple Myeloma: A Population-Based US Study

BACKGROUND

We studied the effect of statins on mortality in a nationally representative sample of patients with multiple myeloma, and explored the benefit of statins in a subgroup of patients treated with novel agents.

METHODS

Patients diagnosed with multiple myeloma between 2007 and 2013 were identified in the SEER-Medicare database using International Classification of Diseases (ICD)-03 codes. ICD-9 and Healthcare Common Procedure Coding System codes were used to identify comorbidities and treatments. We assessed the association of statins with mortality in patients with multiple myeloma using multivariate Cox proportional hazards regression analysis. For subanalysis, we used the same statistical technique to investigate the effect of statins on mortality in myeloma patients treated with novel agents.

RESULTS

A total of 5922 patients were diagnosed with multiple myeloma within the study period. Use of statins was associated with 21% reduction in risk of death (adjusted hazard ratio [aHR] 0.79; 95% confidence interval [CI] 0.74-0.84) among all patients with multiple myeloma. Among the patents treated with novel agents (n = 3603), statins reduced mortality by 10% (aHR = 0.90, 95% CI 0.83-0.98).

CONCLUSIONS

Use of statins is likely associated with lower mortality in patients with multiple myeloma.

The mevalonate pathway is an actionable vulnerability of t(4;14)-positive multiple myeloma

Multiple myeloma (MM) is a plasma cell malignancy that is often driven by chromosomal translocations. In particular, patients with t(4;14)-positive disease have worse prognosis compared to other MM subtypes. Herein, we demonstrated that t(4;14)-positive cells are highly dependent on the mevalonate (MVA) pathway for survival. Moreover, we showed that this metabolic vulnerability is immediately actionable, as inhibiting the MVA pathway with a statin preferentially induced apoptosis in t(4;14)-positive cells. In response to statin treatment, t(4;14)-positive cells activated the integrated stress response (ISR), which was augmented by co-treatment with bortezomib, a proteasome inhibitor. We identified that t(4;14)-positive cells depend on the MVA pathway for the synthesis of geranylgeranyl pyrophosphate (GGPP), as exogenous GGPP fully rescued statin-induced ISR activation and apoptosis. Inhibiting protein geranylgeranylation similarly induced the ISR in t(4;14)-positive cells, suggesting that this subtype of MM depends on GGPP, at least in part, for protein geranylgeranylation. Notably, fluvastatin treatment synergized with bortezomib to induce apoptosis in t(4;14)-positive cells and potentiated the anti-tumor activity of bortezomib in vivo. Our data implicate the t(4;14) translocation as a biomarker of statin sensitivity and warrant further clinical evaluation of a statin in combination with bortezomib for the treatment of t(4;14)-positive disease.

The Innovative Potential of Statins in Cancer: New Targets for New Therapies

Numerous and different types of cancers possess the dysregulation of the mevalonate pathway as a common feature. Statins, traditionally applied in cardiovascular diseases to reduce lipid levels, subsequently have been discovered to exhibit anti-cancer activities also. Indeed, statins influence proliferation, migration, and survival of cancer cells by regulating crucial signaling proteins, such as Rho, Ras, and Rac. Recently, several studies have demonstrated that simvastatin, fluvastatin, and lovastatin are implicated in different pathways that enhance the survival time of patients with cancer under treatment in combination with antineoplastic agents. In this minireview, we present an overview of the most important studies conducted regarding the use of statins in cancer therapy up to date.