Breast cancer screening in women with chronic kidney disease: the unrecognized effects of metastatic soft-tissue calcification

Systemic oncological therapy in breast cancer patients on dialysis

The advancement of renal replacement therapy has significantly enhanced the survival rates of patients with end-stage renal disease (ESRD) over time. However, this prolonged survival has also been associated with a higher likelihood of cancer diagnoses among these patients including breast cancer. Breast cancer treatment typically involves surgery, radiation, and systemic therapies, with approaches tailored to cancer type, stage, and patient preferences. However, renal replacement therapy complicates systemic therapy due to altered drug clearance and the necessity for dialysis sessions. This review emphasizes the need for optimized dosing and administration strategies for systemic breast cancer treatments in dialysis patients, aiming to ensure both efficacy and safety. Additionally, challenges in breast cancer screening and diagnosis in this population, including soft-tissue calcifications, are highlighted.

Associations of Breast Arterial Calcifications with Cardiovascular Disease

Cardiovascular diseases (CVD), including coronary artery disease (CAD), continue to be the leading cause of global mortality among women. While traditional CVD/CAD prevention tools play a significant role in reducing morbidity and mortality among both men and women, current tools for preventing CVD/CAD rely on traditional risk factor-based algorithms that often underestimate CVD/CAD risk in women compared with men. In recent years, some studies have suggested that breast arterial calcifications (BAC), which are benign calcifications seen in mammograms, may be linked to CVD/CAD. Considering that millions of women older than 40 years undergo annual screening mammography for breast cancer as a regular activity, innovative risk prediction factors for CVD/CAD involving mammographic data could offer a gender-specific and convenient solution. Such factors that may be independent of, or complementary to, current risk models without extra cost or radiation exposure are worthy of detailed investigation. This review aims to discuss relevant studies examining the association between BAC and CVD/CAD and highlights some of the issues related to previous studies' design such as sample size, population types, method of assessing BAC and CVD/CAD, definition of cardiovascular events, and other confounding factors. The work may also offer insights for future CVD risk prediction research directions using routine mammograms and radiomic features other than BAC such as breast density and macrocalcifications.

Mammographic features are associated with cardiometabolic disease risk and mortality

AIMS

In recent years, microcalcifications identified in routine mammograms were found to be associated with cardiometabolic disease in women. Here, we aimed to systematically evaluate the association of microcalcifications and other mammographic features with cardiometabolic disease risk and mortality in a large screening cohort and to understand a potential genetic contribution.

METHODS AND RESULTS

This study included 57 867 women from a prospective mammographic screening cohort in Sweden (KARMA) and 49 583 sisters. Cardiometabolic disease diagnoses and mortality and medication were extracted by linkage to Swedish population registries with virtually no missing data. In the cardiometabolic phenome-wide association study, we found that a higher number of microcalcifications were associated with increased risk for multiple cardiometabolic diseases, particularly in women with pre-existing cardiometabolic diseases. In contrast, dense breasts were associated with a lower incidence of cardiometabolic diseases. Importantly, we observed similar associations in sisters of KARMA women, indicating a potential genetic overlap between mammographic features and cardiometabolic traits. Finally, we observed that the presence of microcalcifications was associated with increased cardiometabolic mortality in women with pre-existing cardiometabolic diseases (hazard ratio and 95% confidence interval: 1.79 [1.24-2.58], P = 0.002) while we did not find such effects in women without cardiometabolic diseases.

CONCLUSIONS

We found that mammographic features are associated with cardiometabolic risk and mortality. Our results strengthen the notion that a combination of mammographic features and other breast cancer risk factors could be a novel and affordable tool to assess cardiometabolic health in women attending mammographic screening.

Perspectives From an Onconephrology Interest Group: Conference Report

INTRODUCTION AND OBJECTIVE

Onconephrology is a new and evolving field that deals with kidney complications in patients with cancer as well as the management of cancer in patients with preexisting kidney disease. With increasing numbers of patients with cancer with kidney-related complications, the field has garnered increased attention. Thus, an annual Greater Toronto Area Onconephrology Interest Group symposium was held in May 2019. The objective of the meeting was to demonstrate the junctures between oncology and nephrology by highlighting recent data regarding (1) kidney impairment in solid organ malignancies, (2) management and treatment of kidney cancer, (3) kidney impairment in hematologic malignancies, (4) malignancy and kidney transplantation, and (5) hyponatremia in patients with cancer.

METHODS AND SOURCES OF INFORMATION

Through a structured presentation, the group explored key topics discussed at a Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference on Onconephrology. Expert opinions, clinical trial findings, and publication summaries were used to illustrate patient and treatment-related considerations in onconephrology.

KEY FINDINGS

Kidney complications in patients with cancer are a central theme in onconephrology. An estimated 12% to 25% of patients with solid organ malignancies have chronic kidney disease (CKD), although in certain cancers, the prevalence of CKD is higher. Kidney impairment is also a common complication of some hematologic malignancies. The incidence of renal failure in patients with multiple myeloma is estimated at 18% to 56% and light chain cast nephropathy is seen in approximately 30% of these patients. In addition, there appears to be a bidirectional relationship between kidney cancer and CKD, with some data sets suggesting the risk increases as kidney function declines. Cancer is also of concern in patients with preexisting kidney disease. Kidney transplant recipients have a greater risk of cancer and a higher risk of cancer-related mortality. Kidney complications have also been associated with novel cancer therapies, such as immune checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapy. An estimated 2% to 4% of patients initiating an immune checkpoint inhibitor may develop nephrotoxicity, whereas up to 40% of patients on CAR T-cell therapy experience cytokine release syndrome (CRS). Tumor lysis syndrome and electrolyte abnormalities, such as hyponatremia, have also been reported with CAR T-cell therapy. While the incidence and prevalence of hyponatremia vary depending on the cancer type and serum sodium cutoff point, hyponatremia may be seen in up to 46% of patients hospitalized in cancer centers.

CONCLUSIONS

Onconephrology is a developing field and the themes arising from this meeting indicate a need for greater collaboration between oncologists and nephrologists. Educational symposia and onconephrology fellowship programs may allow for improved cancer care for patients with kidney disease.

Pathological Mineralization: The Potential of Mineralomics

Pathological mineralization has been reported countless times in the literature and is a well-known phenomenon in the medical field for its connections to a wide range of diseases, including cancer, cardiovascular, and neurodegenerative diseases. The minerals involved in calcification, however, have not been directly studied as extensively as the organic components of each of the pathologies. These have been studied in isolation and, for most of them, physicochemical properties are hitherto not fully known. In a parallel development, materials science methods such as electron microscopy, spectroscopy, thermal analysis, and others have been used in biology mainly for the study of hard tissues and biomaterials and have only recently been incorporated in the study of other biological systems. This review connects a range of soft tissue diseases, including breast cancer, age-related macular degeneration, aortic valve stenosis, kidney stone diseases, and Fahr’s syndrome, all of which have been associated with mineralization processes. Furthermore, it describes how physicochemical material characterization methods have been used to provide new information on such pathologies. Here, we focus on diseases that are associated with calcium-composed minerals to discuss how understanding the properties of these minerals can provide new insights on their origins, considering that different conditions and biological features are required for each type of mineral to be formed. We show that mineralomics, or the study of the properties and roles of minerals, can provide information which will help to improve prevention methods against pathological mineral build-up, which in the cases of most of the diseases mentioned in this review, will ultimately lead to new prevention or treatment methods for the diseases. Importantly, this review aims to highlight that chemical composition alone cannot fully support conclusions drawn on the nature of these minerals.

AF1q Contributes to Adriamycin-Induced Podocyte Injury by Activating Wnt/β-Catenin Signaling

BACKGROUND/AIMS

Injury of podocytes plays an important role in decline of glomerular filtration and proteinuria. It is well-known that proteinuria is associated with numerous chronic kidney diseases (CKD). However, the underlying mechanism of podocyte injury remains unclear.

METHODS

We used reverse transcription-quantitative PCR (RT-qPCR) to compare the expression level of the ALL1-fused from the chromosome 1q (AF1q) gene in mice and mouse podocytes (MPC5) with or without Adriamycin (ADR) treatment. The effects of AF1q on Wnt/ β-catenin signaling were investigated by determining the expressions of desmin, snail, WT1, nephrin and E-cadherin using western blotting.

RESULTS

We found that AF1q expression was elevated in podocytes treated with ADR than untreated cells. AF1q overexpression directly led to podocytes injury with increased levels of desmin and snail. Luciferase activity of TOPflash reporter was significantly increased in cells with AF1q overexpression than wild type cells whereas deletion of T-cell-factor-7 (TCF7) eliminated this effect. Immunoprecipitation assay evidenced that AF1q interacted with TCF7 and promoted both transcriptional and translational expressions of TCF7. Overexpression of AF1q increased protein expression of β-catenin. However, in podocytes with deletion of TCF7, AF1q was not able to promote β-catenin expression.

CONCLUSION

Our findings demonstrated that aberrant expression of AF1q may activate Wnt/β-catenin signaling and result in podocyte injury.

Daunting but Worthy Goal: Reducing the De Novo Cancer Incidence After Transplantation

Solid-organ transplant recipients are at increased risk of developing de novo malignancies compared with the general population, and malignancies become a major limitation in achieving optimal outcomes. The prevention and the management of posttransplant malignancies must be considered as a main goal in our transplant programs. For these patients, immunosuppression plays a major role in oncogenesis by both impairement of immunosurveillance, enhancement of chronic viral infection, and by direct prooncogenic effects. It is essential to manage the recipient with a long-term adapted screening program beginning before transplantation to use a prophylaxis to decrease infection-related cancer, to propose a viral monitoring, and to modulate the immunosuppression toward lower doses especially for calcineurin inhibitors. Indeed, strategies to induce tolerance or to allow a dramatic reduction of the immunosuppression burden are the more promising approaches for the reduction of the posttransplant malignancies.

Is chronic kidney disease an independent risk factor for mortality in breast cancer?

BACKGROUND

Chronic kidney disease (CKD) is an independent risk factor for morbidity and mortality in multiple disease processes. However, not much is known about the relationship between breast cancer and CKD. CKD is associated with increased difficulty in breast cancer screening or surveillance due to increased calcifications on mammography. In addition, there is concern regarding the optimization of serum levels of chemotherapeutics in patients with CKD or on hemodialysis. We hypothesized that CKD is an independent risk factor for mortality in patients with breast cancer.

METHODS

A case-matched, retrospective review of a prospectively maintained database was conducted on patients treated for breast cancer at an academic medical center between 1998 and 2011. Glomerular filtration rates (GFRs) were calculated for each patient at the time of diagnosis, and patients with CKD (GFR <60 mL/min) were matched in a 1:2 ratio with patients with GFR >60 mL/min, controlling for age, stage at diagnosis, and race. Primary end points measured were disease-free survival and overall survival. Statistical analysis was performed using Student t-test and Kaplan-Meier.

RESULTS

Of the 1223 total patients, 54 (4%) had CKD. One hundred five patients without CKD were matched for age, stage at diagnosis, and race. Mean GFR among patients with and without CKD were 47.6 and 83.2 mL/min, respectively (P < 0.001). The 5-y overall survival was 77% for patients with CKD and 86% for patients without CKD (P = 0.47). Disease-free survival was 64% and 81%, respectively (P = 0.45).

CONCLUSION

Based on our data, CKD does not appear to have a significant impact on outcomes in patients with breast cancer.

Functional SNP in the microRNA-367 binding site in the 3'UTR of the calcium channel ryanodine receptor gene 3 (RYR3) affects breast cancer risk and calcification

We have evaluated and provided evidence that the ryanodine receptor 3 gene (RYR3), which encodes a large protein that forms a calcium channel, is important for the growth, morphology, and migration of breast cancer cells. A putative binding site for microRNA-367 (miR-367) exists in the 3'UTR of RYR3, and a genetic variant, rs1044129 A→G, is present in this binding region. We confirmed that miR-367 regulates the expression of a reporter gene driven by the RYR3 3'UTR and that the regulation was affected by the RYR3 genotype. A thermodynamic model based on base pairing and the secondary structure of the RYR3 mRNA and miR-367 miRNA showed that miR-367 had a higher binding affinity for the A genotype than for the G genotype. The rs1044129 SNP was genotyped in 1,532 breast cancer cases and 1,600 healthy Chinese women. The results showed that compared with the AA genotype, G was a risk genotype for breast cancer development and was also associated with breast cancer calcification and poor survival. Thus, rs1044129 is a unique SNP that resides in a miRNA-gene regulatory loop that affects breast cancer risk, calcification, and survival.

Cancer incidence and risk factors after solid organ transplantation

Iatrogenic immunosuppression is a unique setting for investigating immune-related mechanisms of carcinogenesis. Solid organ transplant recipients have a 3-fold excess risk of cancer relative to the age- and sex-matched general population. Population-based studies utilizing cancer registry records indicate that a wide range of cancers, mostly those with a viral etiology, occur at excess rates. To date, cancer risk has predominantly been examined in adult kidney transplant recipients in Western countries. It is yet to be established whether a similar incidence profile exists in the long-term for other solid organ, pediatric and non-Western transplant recipients. The cancer incidence profile before and after kidney transplantation strongly suggests a relatively minor contribution by both preexisting cancer risk factors and the conditions underlying end-stage kidney disease, and points to a causal role for immunosuppression. Within-cohort risk factor analyses have largely been performed on cohorts with voluntary cancer notification, and very few have incorporated biomarkers of the level of immunosuppression, the current receipt of immunosuppressive agents, or genetic risk factors. Because of their markedly high risk of certain cancers, findings from comprehensive studies in transplant recipients have the potential to raise new avenues for investigation into causal mechanisms and preventive measures against immune-related and infectious causes of cancer.

Managing cancer risk and decision making after kidney transplantation

Kidney transplant recipients are at higher risk of cancer at most sites, and cancer after transplantation causes considerable morbidity and mortality. To optimize long-term patient outcomes, clinicians balance the prospect of graft failure and dialysis, with competing risks of diabetes, cardiovascular and cerebrovascular disease and the risk of malignancy. In this paper we critically examine the assumptions underpinning primary prevention, immunization, chemoprevention and screening programs, and highlight considerations when applying evidence to the kidney transplant population, and suggest a clinical research agenda that aims to define a rational approach to managing posttransplant cancer risk.