Cancer and the kidney: dangereoux liasons or price paid for the progress in medicine?

A randomized controlled trial comparing pioglitazone and metformin prior to in vitro fertilization in polycystic ovary syndrome - associated infertile women: impact on pregnancy rates

Background

Polycystic ovarian syndrome (PCOS) is one of the significant causes of infertility. Impaired glucose metabolism and insulin resistance add chiefly to the pathogenesis of PCOS. This study aimed to evaluate the efficacy of metformin and pioglitazone (insulin sensitizers) on the quality of the ovum and pregnancy rate in the IVF cycle.

Methods

In this randomized clinical trial study, 172 infertile women with PCO were enrolled and randomly assigned to receive either 15 mg pioglitazone (case group) or 1000 mg metformin (control group) twice a day for 6 weeks before IVF, and the pregnancy rate was compared across the groups. The number of ovum and embryos were also accessed and compared between the two groups.

Results

In the study, 172 patients participated. The mean age in the control and case groups was 32.09±3.9 years and 32.12±3.9 years, respectively, with no significant age difference. In both groups, the mean number of IVF eggs retrieved was 11.76±3.7 (control) and 11.86±3.7 (case), and the number of embryos formed was 7.43±2.8 (control) and 7.87±3.5 (case), with no significant disparities (P<0.05). Regarding positive pregnancies, 28 out of 86 (32.6%) occurred in the control group, while 42 out of 86 (48.8%) happened in the case group, demonstrating a significant difference (P=0.03).

Conclusions

According to the results obtained in this study, it may be concluded that pioglitazone is superior to metformin in IVF cycles in PCOS-associated infertile women leading to a higher pregnancy rate.

Malignancy diseases and kidneys: A nephrologist prospect and updated review

Acute kidney injury (AKI), chronic renal failure, and tubular abnormalities represent the kidney disease spectrum of malignancy. Prompt diagnosis and treatment may prevent or reverse these complications. The pathogenesis of AKI in cancer is multifactorial. AKI affects outcomes in cancer, oncological therapy withdrawal, increased hospitalization rate, and hospital stay. Renal function derangement can be recovered with early detection and targeted therapy of cancers. Identifying patients at higher risk of renal damage and implementing preventive measures without sacrificing the benefits of oncological therapy improve survival. Multidisciplinary approaches, such as relieving obstruction, hydration, etc., are required to minimize the kidney injury rate. Different keywords, texts, and phrases were used to search Google, EMBASE, PubMed, Scopus, and Google Scholar for related original and review articles that serve the article's aim well. In this nonsystematic article, we aimed to review the published data on cancer-associated kidney complications, their pathogenesis, management, prevention, and the latest updates. Kidney involvement in cancer occurs due to tumor therapy, direct kidney invasion by tumor, or tumor complications. Early diagnosis and therapy improve the survival rate. Pathogenesis of cancer-related kidney involvement is different and complicated. Clinicians' awareness of all the potential causes of cancer-related complications is essential, and a kidney biopsy should be conducted to confirm the kidney pathologies. Chronic kidney disease is a known complication in malignancy and therapies. Hence, avoiding nephrotoxic drugs, dose standardization, and early cancer detection are mandatory measures to prevent renal involvement.

Machine learning for acute kidney injury: Changing the traditional disease prediction mode

Acute kidney injury (AKI) is a serious clinical comorbidity with clear short-term and long-term prognostic implications for inpatients. The diversity of risk factors for AKI has been recognized in previous studies, and a series of predictive models have been developed using traditional statistical methods in conjunction with its preventability, but they have failed to meet the expectations in limited clinical applications, the rapid spread of electronic health records and artificial intelligence machine learning technology has brought new hope for the construction of AKI prediction models. In this article, we systematically review the definition and classification of machine learning methods, modeling ideas and evaluation methods, and the characteristics and current status of modeling studies. According to the modeling objectives, we subdivided them into critical care medical setting models, all medical environment models, special surgery models, special disease models, and special nephrotoxin exposure models. As the first review article to comprehensively summarize and analyze machine learning prediction models for AKI, we aim to objectively describe the advantages and disadvantages of machine learning approaches to modeling, and help other researchers more quickly and intuitively understand the current status of modeling research, inspire ideas and learn from experience, so as to guide and stimulate more research and more in-depth exploration in the future, which will ultimately provide greater help to improve the overall status of AKI diagnosis and treatment.

Risk of malignancy in patients with chronic kidney disease

Background

Fifteen percent of US adults have chronic kidney disease (CKD). The effect of CKD on the development of different malignancies is unknown. Understanding the effect of CKD on the risk of development of cancer could have important implications for screening and early detection of cancer in these patients.

Methods

Adult CKD patients [estimated GFR (eGFR) <60ml/min/1.73m²] between January 2001 and December 2020 were identified in this single institution study. Patients were divided into four stages of CKD by eGFR. The incidence of cancer and time to development of the first cancer were identified. Multivariable models were used to compare the overall cancer incidence while considering death as a competing risk event and adjusting for relevant covariates (sex, race, diabetes, hypertension, CAD, smoking or not, BMI, and CKD stages). Separate multivariable models of the incidence of cancers were conducted in each age group. Multivariable Cox models were used to fit the overall death adjusting for relevant covariates. Patients were censored at the conclusion of the study period (December 31, 2020). Statistical analysis was performed with SAS software (version 9.4).

Results

Of the 13,750 patients with a diagnosis of CKD in this cohort, 2,758 (20.1%) developed a malignancy. The median time to development of cancer following a diagnosis of CKD was 8.5 years. Factors associated with the risk of developing cancer in CKD patients included increasing age, male sex and worsening chronic kidney disease, while diabetes was associated with a lower risk of malignancy. On multivariate analysis, the factors associated with increased mortality in patients who developed cancer included increasing age, diabetes and lower eGFR.

Conclusion

CKD is an increased risk factor for the development of various malignancies. Age appropriate cancer screening should be aggressively pursued in those with progressive CKD.

Molecular Mechanisms and Biomarkers Associated with Chemotherapy-Induced AKI

Acute kidney injury (AKI) is a life-threatening condition characterized by a rapid and transient decrease in kidney function. AKI is part of an array of conditions collectively defined as acute kidney diseases (AKD). In AKD, persistent kidney damage and dysfunction lead to chronic kidney disease (CKD) over time. A variety of insults can trigger AKI; however, chemotherapy-associated nephrotoxicity is increasingly recognized as a significant side effect of chemotherapy. New biomarkers are urgently needed to identify patients at high risk of developing chemotherapy-associated nephrotoxicity and subsequent AKI. However, a lack of understanding of cellular mechanisms that trigger chemotherapy-related nephrotoxicity has hindered the identification of effective biomarkers to date. In this review, we aim to (1) describe the known and potential mechanisms related to chemotherapy-induced AKI; (2) summarize the available biomarkers for early AKI detection, and (3) raise awareness of chemotherapy-induced AKI.

KDIGO Controversies Conference on onco-nephrology: kidney disease in hematological malignancies and the burden of cancer after kidney transplantation

The bidirectional relationship between cancer and chronic kidney disease (CKD) is complex. Patients with cancer, particularly those with hematological malignancies such as multiple myeloma and lymphoma, are at increased risk of developing acute kidney injury and CKD. On the other hand, emerging evidence from large observational registry analyses have consistently shown that cancer risk is increased by at least 2- to 3-fold in kidney transplant recipients, and the observed increased risk occurs not only in those who have received kidney transplants but also in those on dialysis and with mild- to moderate-stage CKD. The interactions between cancer and CKD have raised major therapeutic and clinical challenges in the management of these patients. Given the magnitude of the problem and uncertainties, and current controversies within the existing evidence, Kidney Disease: Improving Global Outcomes (KDIGO) assembled a global panel of multidisciplinary clinical and scientific expertise for a controversies conference on onco-nephrology to identify key management issues in nephrology relevant to patients with malignancy. This report covers the discussed controversies in kidney disease in hematological malignancies, as well as cancer after kidney transplantation. An overview of future research priorities is also discussed.

Protective effect of tolvaptan against cyclophosphamide-induced nephrotoxicity in rat models

Cyclophosphamide (CP) is a chemotherapeutic agent which is extensively used in the treatment of multiple neoplastic and nonneoplastic diseases like breast cancer, lymphomas, systemic lupus erythematosus, and multiple sclerosis. Dose-limiting side effects, mainly nephrotoxicity is a major problem hindering its use in the clinical practice. CP induces nephrogenic syndrome of inappropriate antidiuresis mostly via the activation of arginine vasopressin V2 receptors. Moreover, CP produces reactive metabolites which is responsible for augmentation of lipid peroxidation and oxidative stress. Tolvaptan (TOL) is a selective vasopressin V2 receptor antagonist used in the treatment of clinically significant hyponatremia, volume overload in heart failure, and liver cirrhosis with edema. The present study aimed to investigate the potential protective effect of TOL in CP-induced nephrotoxicity. Twenty-four adult male albino rats were randomly divided into four groups: the control group, TOL group that treated daily with tolvaptan (10 mg/kg/d, orally), CP group where CP was administered intraperitoneally 75 mg/kg on days 3, 4, 5, 19, 20, and 21 of study, and the CP + TOL group where animals were treated with TOL daily with (10 mg/kg/d, orally) for 22 days with concomitant administration of CP as described before. Coadministration of TOL with CP induces significant improvement in the level of urine volume, serum Na+, serum osmolarity, urinary creatinine, and free water clearance in addition to significant reduction of body weight, serum creatinine, urea, serum K+, blood pressure, urine osmolarity, and the fractional excretion of sodium as compared to CP-treated group. In addition, coadministration of TOL significantly reduced MDA, the marker of lipid peroxidation, and different pro-inflammatory cytokines. Histopathological changes showed improvement in the signs of nephrotoxicity with the coadministration of TOL. Also, co-treatment with TOL significantly decreased the level of markers of apoptosis as caspase-3 and Bax with increased expression of antiapoptotic Bcl-2 in renal tissue as compared to CP-treated group.

Prediction models for acute kidney injury in patients with gastrointestinal cancers: a real-world study based on Bayesian networks

Background

This study attempts to establish a Bayesian networks (BNs) based model for inferring the risk of AKI in gastrointestinal cancer (GI) patients, and to compare its predictive capacity with other machine learning (ML) models.

Methods

From 1 October 2014 to 30 September 2015, we recruited 6495 inpatients with GI cancers in a tertiary hospital in eastern China. Data on demographics, clinical and laboratory indicators were retrospectively extracted from the electronic medical record system. Predictors of AKI were selected in gLASSO regression, and further incorporated into BNs analysis.

Results

The incidences of AKI in patients with esophagus, stomach, and intestine cancer were 20.5%, 13.9%, and 12.5%, respectively. Through gLASSO, 11 predictors were screened out, including diabetes, cancer category, anti-tumor treatment, ALT, serum creatinine, estimated glomerular filtration rate (eGFR), serum uric acid (SUA), hypoalbuminemia, anemia, abnormal sodium, and potassium. BNs model revealed that cancer category, treatment, eGFR, and hypoalbuminemia had direct connections with AKI. Diabetes and SUA were indirectly linked to AKI through eGFR, and anemia created connections with AKI through affecting album level. Compared with other ML models, BNs model maintained a higher AUC value in both the internal and external validation (AUC: 0.823/0.790).

Conclusion

BNs model not only delineates the qualitative and quantitative relationship between AKI and its associated factors but shows the more robust generalizability in AKI prediction.

Immune Dysfunction in Uremia 2020

Cardiovascular disease and infections are major causes for the high incidence of morbidity and mortality of patients with chronic kidney disease. Both complications are directly or indirectly associated with disturbed functions or altered apoptotic rates of polymorphonuclear leukocytes, monocytes, lymphocytes, and dendritic cells. Normal responses of immune cells can be reduced, leading to infectious diseases or pre-activated/primed, giving rise to inflammation and subsequently to cardiovascular disease. This review summarizes the impact of kidney dysfunction on the immune system. Renal failure results in disturbed renal metabolic activities with reduced renin, erythropoietin, and vitamin D production, which adversely affects the immune system. Decreased kidney function also leads to reduced glomerular filtration and the retention of uremic toxins. A large number of uremic toxins with detrimental effects on immune cells have been identified. Besides small water-soluble and protein-bound compounds originating from the intestinal microbiome, several molecules in the middle molecular range, e.g., immunoglobulin light chains, retinol-binding protein, the neuropeptides Met-enkephalin and neuropeptide Y, endothelin-1, and the adipokines leptin and resistin, adversely affect immune cells. Posttranslational modifications such as carbamoylation, advanced glycation products, and oxidative modifications contribute to uremic toxicity. Furthermore, high-density lipoprotein from uremic patients has an altered protein profile and thereby loses its anti-inflammatory properties.

Why is renal impairment associated with poorer cancer specific survival in breast cancer patients?: a comparison with patients with other comorbidities

Background

Our aim is to assess whether the poor breast cancer specific survival (BCSS) seen in women with breast cancer and impaired renal function can be explained by associations with other prognostic factors.

Methods

The study group was a consecutive series of patients undergoing breast ultrasound (US) who had invasive breast cancer (n = 1171). All women had their US diameter and mean stiffness (kPa) at shear wave elastography (SWE) recorded. The core biopsy grade and receptor status were noted. Core biopsy of abnormal axillary nodes and the patient referral source was also noted. Survival including cause of death was ascertained. Comorbidities at diagnosis were recorded. Patients were divided into those with a GFR<60 (“renal group”), those with other comorbidities and those with none. BCSS was assessed using Kaplan–Meier survival curves and Cox proportional hazards regression.

Results

One thousand, one hundred and forty-one patients constituted the study group. 107 (9%) patients had impaired renal function, 182 (16%) had other comorbidities while 852 (75%) had no comorbidities. Mean follow-up was 5.8 years. 109 breast cancer and 122 non-breast cancer deaths occurred. BCSS in the renal group was significantly worse than the other groups. Women with renal comorbidity were older, more likely to present symptomatically, have a pre-operative diagnosis of axillary metastases, and have larger and stiffer cancers. Cox proportional hazards regression showed that renal impairment maintained independent significance.

Conclusion

The poor BCSS in women with impaired renal function is partially explained by advanced tumour stage at presentation. However, impaired renal function maintains an independent prognostic effect.

Children of a lesser god: exclusion of chronic kidney disease patients from clinical trials

The exclusion of chronic kidney disease (CKD) patients from clinical trials-particularly cardiovascular trials-remains a long-standing, unsolved problem, which prevents the optimization of clinical care in these patients. The situation recalls the insufficient recruitment of women in cardiovascular trials until the 1980s, a problem that was only resolved following regulatory interventions. Regulatory agencies are in a unique position to promote recruitment of CKD patients in clinical trials. The main stakeholders, namely patients' associations and scientific societies, should make major lobbying efforts to persuade these agencies that the issue is an absolute public health priority.

Epidemiology of acute kidney injury and associated factors among patients with malignancy: Analysis of hospital inpatient database in Shanghai, China

Objective:

This study aimed to understand the incidence of acute kidney injury in cancer patients, to figure out which clinical factors could increase the risks of acute kidney injury, and then to assess the effect of acute kidney injury on in-hospital mortality, length of stay, and hospital cost.

Methods:

This study was designed as a retrospective cohort study based on the hospital inpatient database in Zhongshan Hospital, Shanghai, China. Patients with malignancy and admitted to the hospital between 1 October 2014 and 30 September 2015 were recruited. Data on demographics, comorbidities, and clinical records were exported for analysis. Acute kidney injury was diagnosed using KDIGO (Kidney Disease: Improving Global Outcomes) criteria and stratified into community-acquired and hospital-acquired acute kidney injury. Multivariate model and survival analysis were applied to discover the influencing factors of acute kidney injury among cancer patients.

Results:

Of the 26,914 eligible cancer admissions, 3326 acute kidney injury cases were identified with an incidence of 12.4%. Of them, 2961 patients located in acute kidney injury stage 1 and another 365 cases developed to stage 2–3. The highest rates were localized to renal cancer (27.3%), multiple myeloma (24.1%), and leukemia (23.9%). Patients with older age and hematologic cancer shared a higher acute kidney injury incidence. Pre-existing chronic kidney disease (adjusted odds ratio = 7.14), heart failure (adjusted odds ratio = 4.20), surgery/chemotherapy (adjusted odds ratio = 0.99/2.28), hyponatremia (adjusted odds ratio = 2.84), hypokalemia (adjusted odds ratio = 2.42), and hyperuricemia (adjusted odds ratio = 2.62) were the major factors associated with acute kidney injury. In-hospital mortality for acute kidney injury patients was 5.1% as compared with those without acute kidney injury (0.8%). Survival analysis reveals that the risk of death was higher among patients with hospital-acquired acute kidney injury (adjusted hazard ratio = 4.50) and severe acute kidney injury stage (adjusted hazard ratio = 2.68/3.91). Furthermore, the length of stay (13.5 days) and hospital cost (45,066 CNY) were significantly greater in patients with community-acquired acute kidney injury.

Conclusion:

Acute kidney injury was common in cancer patients and associated with an ominous outcome. Pre-existing comorbidities, electrolyte disturbances, and abnormal biochemical were the predicting factors for acute kidney injury incidence. Better monitoring of electrolytes, identification of high-risk patients, and early acute kidney injury diagnosis should be considered as a priority during anti-cancer treatment.

Progression to chronic kidney disease in patients undergoing nephrectomy for small renal masses: a price to pay for a therapeutic success?

Nephrectomy, which constitutes a gold-standard procedure for the treatment of renal-cell carcinoma (RCC), has been widely discussed in the past decade as a significant risk factor of the development of chronic kidney disease (CKD). RCC is the third most common genitourinary cancer in the United States, with an estimated more than 65,000 new cases and 14,970 deaths. The aim of this review was to precisely and comprehensively summarize the status of current knowledge in CKD risk factors after nephrectomy, the advantages of minimally invasive vs. radical nephrectomy, post-nephrectomy biomarkers of CKD, ways of post-operative CKD prevention and, therefore, better understand why various aspects of CKD after nephrectomy. The majority of current studies indicated a better long-term kidney function preservation in patients undergoing partial nephrectomy in comparison to those after radical nephrectomy. Furthermore, a nephron-sparing surgery should be a preferred first-line procedure among young patients with small renal masses. As partial nephrectomy is followed by a greater risk of adverse outcomes relative to radical nephrectomy, a potential survival benefit should always be considered especially in the elderly or patients with comorbidities.

Adhesion GPCRs in Kidney Development and Disease

Chronic kidney disease (CKD) represents the fastest growing pathology worldwide with a prevalence of >10% in many countries. In addition, kidney cancer represents 5% of all new diagnosed cancers. As currently no effective therapies exist to restore kidney function after CKD- as well as cancer-induced renal damage, it is important to elucidate new regulators of kidney development and disease as new therapeutic targets. G protein-coupled receptors (GPCRs) represent the most successful class of pharmaceutical targets. In recent years adhesion GPCRs (aGPCRs), the second largest GPCR family, gained significant attention as they are present on almost all mammalian cells, are associated to a plethora of diseases and regulate important cellular processes. aGPCRs regulate for example cell polarity, mitotic spindle orientation, cell migration, and cell aggregation; all processes that play important roles in kidney development and/or disease. Moreover, polycystin-1, a major regulator of kidney development and disease, contains a GAIN domain, which is otherwise only found in aGPCRs. In this review, we assess the potential of aGPCRs as therapeutic targets for kidney disease. For this purpose we have summarized the available literature and analyzed data from the databases The Human Protein Atlas, EURExpress, Nephroseq, FireBrowse, cBioPortal for Cancer Genomics and the National Cancer Institute Genomic Data Commons data portal (NCIGDC). Our data indicate that most aGPCRs are expressed in different spatio-temporal patterns during kidney development and that altered aGPCR expression is associated with a variety of kidney diseases including CKD, diabetic nephropathy, lupus nephritis as well as renal cell carcinoma. We conclude that aGPCRs present a promising new class of therapeutic targets and/or might be useful as diagnostic markers in kidney disease.

Renal Impairment Hampers Bisphosphonate Treatment in a Quarter of Lung Cancer Patients with Bone Metastasis

Renal function impairment in lung cancer patients with bone metastases was investigated, as this can limit the application of bisphosphonates representing the gold standard in the management of such cases. Clinicopathological data of 570 lung cancer patients were retrospectively analysed for changes in renal function parameters. Comorbidities included hypertension (50%), COPD (33%) and diabetes mellitus (15%). Statistical analysis was performed with Fisher's exact tests and a Cox proportional hazards model. In patients suffering from hypertension, both median serum creatinine and blood urea nitrogen (BUN) were higher (81.9 versus 75.8 μmol/L, p < 0.001 and 6.0 versus 5.7 mmol/L, p = 0.005, respectively). Such a difference could not be observed in patients with diabetes. In patients with COPD, only serum creatinine was higher (81.1 versus 77.3 μmol/L, p = 0.004). In the whole cohort, we found that while at the time of lung cancer diagnosis the ratio of patients in the pathological range (PRR) was 8.67% for serum creatinine (median: 75 μmol/L) and 14.16% for BUN (median: 5.4 mmol/L), at the time of bone metastasis the PRR for serum creatinine increased to 16.11% (median: 77.0 μmol/L) and for BUN to 24.07% (median: 6.0 mmol/L), which is a significant increase for both parameters (p < 0.001). For the whole cohort, the last laboratory results showed a 26.37% PRR for serum creatinine and 45.66% PRR for BUN (significant increase for both, p < 0.001). Multivariate analysis revealed that patients with hypertension had a higher chance for switching to the pathological range sooner (p = 0.033, HR: 1.372, CI: 1.025-1.835). Also, the appearance of the bone metastasis correlated with an acceleration of the onset of such a switch (p < 0.001, HR: 2.655, CI: 1.581-4.456). Our results suggest that renal function is impaired in a significant proportion of patients with lung cancer and highlight the importance of non-nephrotoxic drug in the management of bone metastases.