Variation in Cancer Incidence among Patients with ESRD during Kidney Function and Nonfunction Intervals

Cancer in kidney transplant recipients

Cancer is the second most common cause of mortality and morbidity in kidney transplant recipients after cardiovascular disease. Kidney transplant recipients have at least a twofold higher risk of developing or dying from cancer than the general population. The increased risk of de novo and recurrent cancer in transplant recipients is multifactorial and attributed to oncogenic viruses, immunosuppression and altered T cell immunity. Transplant candidates and potential donors should be screened for cancer as part of the assessment process. For potential recipients with a prior history of cancer, waiting periods of 2-5 years after remission - largely depending on the cancer type and stage of initial cancer diagnosis - are recommended. Post-transplantation cancer screening needs to be tailored to the individual patient, considering the cancer risk of the individual, comorbidities, overall prognosis and the screening preferences of the patient. In kidney transplant recipients diagnosed with cancer, treatment includes conventional approaches, such as radiotherapy and chemotherapy, together with consideration of altering immunosuppression. As the benefits of transplantation compared with dialysis in potential transplant candidates with a history of cancer have not been assessed, current clinical practice relies on evidence from observational studies and registry analyses.

Long-Term Outcomes after Acute Rejection in Kidney Transplant Recipients: An ANZDATA Analysis

BACKGROUND

Declining rates of acute rejection (AR) and the high rate of 1-year graft survival among patients with AR have prompted re-examination of AR as an outcome in the clinic and in trials. Yet AR and its treatment may directly or indirectly affect longer-term outcomes for kidney transplant recipients.

METHODS

To understand the long-term effect of AR on outcomes, we analyzed data from the Australia and New Zealand Dialysis and Transplant Registry, including 13,614 recipients of a primary kidney-only transplant between 1997 and 2017 with at least 6 months of graft function. The associations between AR within 6 months post-transplant and subsequent cause-specific graft loss and death were determined using Cox models adjusted for baseline donor, recipient, and transplant characteristics.

RESULTS

AR occurred in 2906 recipients (21.4%) and was associated with graft loss attributed to chronic allograft nephropathy (hazard ratio [HR], 1.39; 95% confidence interval [95% CI], 1.23 to 1.56) and recurrent AR beyond month 6 (HR, 1.85; 95% CI, 1.39 to 2.46). Early AR was also associated with death with a functioning graft (HR, 1.22; 95% CI, 1.08 to 1.36), and with death due to cardiovascular disease (HR, 1.30; 95% CI, 1.11 to 1.53) and cancer (HR, 1.35; 95% CI, 1.12 to 1.64). Sensitivity analyses restricted to subgroups with either biopsy-proven, antibody-mediated, or vascular rejection, or stratified by treatment response produced similar results.

CONCLUSIONS

AR is associated with increased risks of longer-term graft failure and death, particularly death from cardiovascular disease and cancer. The results suggest AR remains an important short-term outcome to monitor in kidney transplantation and clinical trials.

Aristolochic Acid and Immunotherapy for Urothelial Carcinoma: Directions for unmet Needs

Urothelial carcinoma of the bladder (UCB) and upper tracts (UTUC) used to share management with similar principles. However, their genetic and epigenetic differences along with different responses to immunotherapy were recently identified, which are reminiscent of their distinct etiologies. Different from the variety of environmental factors relating to UCB, UTUC is best known for its close relationship with exposure to aristolochic acid (AA). AA is believed to cause its carcinogenicity through forming DNA adducts of deoxyadenosine-aristolactam, as well as A:T → T:A transversions in the TP53 tumor suppressor gene. Since recent findings suggested that cancers with higher somatic mutations are associated with better treatment responses upon immune checkpoint blockade, UTUC and AA-related biomarkers reasonably serve as good candidates, as well as a potential prognostic predictor for the flourishing immunotherapy. This review covers the current state of the literature on the clinical response of UTUC and UCB receiving immunotherapy and points out directions for refinement regarding patient selection.

Gender differences in cancer risk after kidney transplantation

Kidney transplant (KT) recipients are at greater risk of developing some cancers than the general population. Moreover, cancer is the only cause of death that is currently increasing after kidney transplantation. We analyzed incidence, risk factors and characteristics of post-transplant malignancies (solid organ tumors and lymphoproliferative disorders) at our center in 925 KT recipients (1979-2014). Sex differences were particularly assessed. One hundred and eight patients (11.7%) developed solid organ tumors (76.9%) or lymphoma (23.1%). Twenty-one percent of patients who reached 20 years after KT developed cancer, with a median post-KT time to diagnosis of 7.4 years. Most common solid organs affected were lung (30.1%), prostate (10.8%), bladder (9.6%), and native kidney (7.2%). When analyzing standardized incidence ratios (SIR) by gender compared to the general population, relative risk was increased in women (SIR = 1.81; 95%CI, 1.28-2.45) but not significantly increased in men (SIR = 1.22; 0.95-2.52). Regarding specific types, gynecological (SIR = 11.6; 4.2-22.7) and lung (SIR = 10.0; 4.3-18.2) in women, and bladder (SIR = 16.3; 5.9-32.1) in men were the most affected locations. Thymoglobulin, a polyclonal antibody that has been used as an immunosuppressive agent in kidney transplantation over the last decades, was a significant risk factor for developing cancer in adjusted regression analysis [IRR = 1.62, 1.02-2.57; p = 0.041], and was associated with lower patient survival. Compared with the general population, the incidence of post-KT non-skin cancer is almost two-fold higher in women but not significantly higher in men. Lung is the most common solid organ affected. Thymoglobulin induction therapy is associated with a greater risk.

Thyroid disease and cancer in kidney transplantation: a single-center analysis

BACKGROUND

Thyroid diseases are frequent in patients with end-stage renal disease, but data on renal transplant recipients are conflicting. This study evaluated the incidence of thyroid disease and cancer in a population of kidney transplant recipients performed in a single center.

METHODS

Seven hundred sixty patients receiving a kidney transplantation between January 2000 and October 2017 were followed with thyroid ultrasonography to determine nodules together with thyroid hormone levels. Ultrasound-guided fine-needle aspiration citology (FNAc) was performed to the nodules > 10 mm .

RESULTS

Two hundred four patients (26.8%) patients demonstrated functional or morphologic changes in the thyroid gland compared with pre-transplant period. Among the 204 patients with newly diagnosed thyroid disease, 165 patients had single or multiple nodular lesions less than 1 cm in diameter, and were followed yearly. Nodule size progression was observed in 23 patients (13.9%), and they underwent a FNAc. A total of sixty-two patients (30.3%) underwent FNAc. The biopsy samples were cytologically interpreted as benign in 20 patients (32.2%), suspicious in 40 patients (64.5%), or at high risk of cancer in 2 patients (3.2%). Forty-two patients underwent total thyroidectomy. At histological examination, 18 patients had a thyroid cancer (papillary cancer in 17 patients, follicular cancer in one). Thyroid cancer was more frequent in male patients with a mean time from transplant to diagnosis of 5.6 years. At a mean follow-up was 8 ± 1.2 years, all patients are alive with a normal functioning graft.

CONCLUSIONS

Thyroid diseases are common in transplant recipients. Thyroid disease may evolve after transplantation, probably as a consequence of immunosuppression. A complete evaluation of thyroid disease is mandatory in kidney transplant recipients because early diagnosis and appropriate treatment of thyroid disease and cancer may significantly decrease the morbidity and mortality in these patients.

Association between urologic malignancies and end-stage renal disease: A meta-analysis

AIM

Previous studies have suggested a higher incidence of urologic malignancies in end-stage renal disease (ESRD) patients. However, incidence trends of urologic malignancies in ESRD patients remain unclear. The aims of the present study were: (i) to investigate the pooled incidence/incidence trends; and (ii) to assess the risk of urologic malignancies in ESRD patients.

METHODS

A literature search was conducted using MEDLINE, EMBASE and Cochrane Database from inception through April 2017. Studies that reported incidence or odds ratios of urologic malignancies among ESRD patients were included. Pooled odds ratios (OR) and 95%CI were calculated using a random-effect model. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42017067687).

RESULTS

Nineteen observational studies with 1 931 073 ESRD patients were enrolled. The pooled estimated incidence of kidney cancer and urothelial cancers (carcinomas of the bladder, ureters, and renal pelvis) in ESRD patients were 0.3% (95%CI: 0.2-0.5%) and 0.5% (95%CI: 0.3-0.8%), respectively. Meta-regression showed significant positive correlation between incidence of urologic malignancies in ESRD patients and year of study (slopes = +0.05 and +0.07, P < 0.001 for kidney cancer and urothelial cancers, respectively). Compared to non-ESRD status, ESRD was significantly associated with both kidney cancer (pooled OR 6.04; 95% CI 4.70-7.77) and urothelial cancers (pooled OR 4.37; 95% CI 2.40-7.96).

CONCLUSION

Our study demonstrates a significant association between ESRD and urologic malignancies. The overall estimated incidence rates of kidney cancer and urothelial cancers are 0.4% and 0.5%, respectively. There is a significant positive correlation between the incidence of urologic malignancies and year of study.

Overall and Site-Specific Cancer Mortality in Patients on Dialysis and after Kidney Transplant

Background Patients with ESRD have a substantially increased cancer risk, but few studies have examined the patterns of cancer mortality along a patient's journey from dialysis to transplantation.

METHODS

We identified all Australian patients on dialysis and patients with transplants from 1980 to 2014 from the Australia and New Zealand Dialysis and Transplant Registry. Using standardized mortality ratios (SMRs), we compared cancer mortality among patients on dialysis and patients with transplants versus the general population (overall and by age, sex, year, and site); we also performed a subgroup analysis excluding patients with preexisting cancers.

RESULTS

We followed 52,936 patients on dialysis and 16,820 transplant recipients for 170,055 and 128,352 patient-years, respectively. There were 2739 cancer deaths among patients on dialysis and 923 cancer deaths among transplant recipients. Overall, cancer SMRs were 2.6 for patients on dialysis and 2.7 for transplant recipients. For patients on dialysis, SMRs were highest for multiple myeloma (30.5), testicular cancer (17.0), and kidney cancer (12.5); for transplant recipients, SMRs were highest for non-Hodgkin lymphoma (10.7), kidney cancer (7.8), and melanoma (5.8). Some 61.0% of patients on dialysis and 9.6% of transplant recipients who experienced cancer death had preexisting cancer. The SMRs for de novo cancer was 1.2 for patients on dialysis and 2.6 for transplant recipients.

CONCLUSIONS

Patients on dialysis and transplant recipients experienced >2.5-fold increased risk of cancer death compared with the general population. This increased risk was largely driven by preexisting cancers in patients on dialysis and de novo cancers in patients with transplants.

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.

Risk factors associated with post-kidney transplant malignancies: an article from the Cancer-Kidney International Network

In kidney transplant recipients, cancer is one of the leading causes of death with a functioning graft beyond the first year of kidney transplantation, and malignancies account for 8-10% of all deaths in the USA (2.6 deaths/1000 patient-years) and exceed 30% of deaths in Australia (5/1000 patient-years) in kidney transplant recipients. Patient-, transplant- and medication-related factors contribute to the increased cancer risk following kidney transplantation. While it is well established that the overall immunosuppressive dose is associated with an increased risk for cancer following transplantation, the contributive effect of different immunosuppressive agents is not well established. In this review we will discuss the different risk factors for malignancies after kidney transplantation.

Comprehensive review of post-organ transplant hematologic cancers

A higher risk for a variety of cancers is among the major complications of posttransplantation immunosuppression. In this part of a continuing series on cancers posttransplantation, this review focuses on the hematologic cancers after solid organ transplantation. Posttransplantation lymphoproliferative disorders (PTLDs), which comprise the great majority of hematologic cancers, represent a spectrum of conditions that include, but are not limited to, the Hodgkin and non-Hodgkin lymphomas. The oncogenic Epstein-Barr virus is a key pathogenic driver in many PTLD cases, through known and unknown mechanisms. The other hematologic cancers include leukemias and plasma cell neoplasms (multiple myeloma and plasmacytoma). Clinical features vary across malignancies and location. Preventive screening strategies have been attempted mainly for PTLDs. Treatments include the chemotherapy regimens for the specific cancers, but also include reduction of immunosuppression, rituximab, and other therapies.

Urologic malignancies in kidney transplantation

With advances in immunosuppression, graft and patient outcomes after kidney transplantation have improved considerably. As a result, long-term complications of transplantation, such as urologic malignancies, have become increasingly important. Kidney transplant recipients, for example, have a 7-fold risk of renal cell carcinoma (RCC) and 3-fold risk of urothelial carcinoma (UC) compared with the general population. While extrapolation of data from the general population suggest that routine cancer screening in transplant recipients would allow for earlier diagnosis and management of these potentially lethal malignancies, currently there is no consensus for posttransplantation RCC or UC screening as supporting data are limited. Further understanding of risk factors, presentation, optimal management of, and screening for urologic malignancies in kidney transplant patients is warranted, and as such, this review will focus on the incidence, surveillance, and treatment of urologic malignancies in kidney transplant recipients.

Risk of Thyroid Cancer Among Solid Organ Transplant Recipients

Solid organ transplant recipients have an elevated incidence of thyroid cancer. We evaluated a wide range of potential risk factors in a cohort of 229 300 U.S. solid organ transplant recipients linked with 15 stage/regional cancer registries (1987-2012). Incidence rate ratios (IRRs) were adjusted for age, sex, race/ethnicity, transplanted organ, year of transplantation, and time since transplantation. Hazard ratios (HRs) for death and/or graft failure were adjusted for age, sex, race/ethnicity, transplanted organ, and year of transplantation. After transplantation, 356 thyroid cancers were diagnosed. Thyroid cancer incidence was 2.50-fold higher in transplant recipients than the general population (95% confidence interval [CI] 2.25-2.77). Among recipients of different organs, kidney recipients had the highest incidence of thyroid cancer (IRR = 1.26, 95% CI 1.03-1.53). Elevated thyroid cancer incidence was associated with cholestatic liver disease/cirrhosis as an indication for liver transplantation (IRR = 1.69, 95% CI 1.09-2.63), hypertensive nephrosclerosis as an indication for kidney transplantation (IRR = 1.41, 95% CI 1.03-1.94), and longer prior dialysis among kidney recipients (5+ vs. <1 year, IRR = 1.92, 95% CI 1.32-2.80; p-trend <0.01). Posttransplantation diagnosis of thyroid cancer was associated with modestly increased risk of death (HR = 1.33, 95% CI 1.02-1.73). Overall, our results suggest that end-stage organ disease and longer duration of dialysis may contribute to higher thyroid cancer incidence in transplant recipients.

Incidence and Predictors of Cancer Following Kidney Transplantation in Childhood

Cancer risk is increased substantially in adult kidney transplant recipients, but the long-term risk of cancer in childhood recipients is unclear. Using the Australian and New Zealand Dialysis and Transplant Registry, the authors compared overall and site-specific incidences of cancer after transplantation in childhood recipients with population-based data by using standardized incidence ratios (SIRs). Among 1734 childhood recipients (median age 14 years, 57% male, 85% white), 289 (16.7%) developed cancer (196 nonmelanoma skin cancers, 143 nonskin cancers) over a median follow-up of 13.4 years. The 25-year cumulative incidences of any cancer were 27% (95% confidence intervals 24-30%), 20% (17-23%) for nonmelanoma skin cancer, and 14% (12-17%) for nonskin cancer (including melanoma). The SIR for nonskin cancer was 8.23 (95% CI 6.92-9.73), with the highest risk for posttransplant lymphoproliferative disease (SIR 45.80, 95% CI 32.71-62.44) and cervical cancer (29.4, 95% CI 17.5-46.5). Increasing age at transplantation (adjusted hazard ratio [aHR] per year 1.10, 95% CI 1.06-1.14), white race (aHR 3.36, 95% CI 1.61-6.79), and having a functioning transplant (aHR 2.27, 95% CI 1.47-3.71) were risk factors for cancer. Cancer risk, particularly for virus-related cancers, is increased substantially after kidney transplantation during childhood.

Long-term allograft and patient outcomes of kidney transplant recipients with and without incident cancer - a population cohort study

The excess risk for cancer in kidney transplant recipients is substantial, but the allograft and patient survivals after cancer development are under-studied. This is a population-based cohort study of all primary live and deceased donor kidney transplant recipients in Australia and New Zealand between 1990-2012. The risks of overall graft loss and death with a functioning graft in kidney transplant recipients with and without incident cancer were determined using adjusted Cox regression analysis, with incident cancer considered as a time-varying covariate in the models. In those with incident cancer, types and cancer stage at diagnoses were reported. Of 12,545 transplant recipients followed for a median of 6.9 years (91,380 patient-years), 1184 (9.4%) developed incident cancers at a median of 5.8 years post-transplant. Digestive, kidney and urinary tract cancers were the most common cancer types, although digestive and respiratory tract cancers were more aggressive, with 40% reported as advanced cancers at time of cancer diagnosis. Cancer-related deaths accounted for approximately 80% of recipients with a prior cancer history. Compared with recipients with no prior cancer, the adjusted hazard ratios (HR) for overall graft loss and death with functioning graft were 4.34 (95%CI 3.90, 4.82; p<0.001) and 9.53 (95%CI 8.30, 10.95; <0.001) among those with a prior cancer. Incident cancer after kidney transplantation is a significant risk factor for death with a functioning graft, with the majority of deaths attributed to cancer. A greater understanding of the barriers to screening and treatment approaches following cancer diagnosis may lead to improve survival in kidney transplant recipients with cancer.

Breast Cancer and Transplantation

Breast cancer is an important cancer among solid organ transplant recipients. While the incidence of breast cancer in solid organ transplant recipients is comparable to the age-matched general population, the outcomes are generally poor. Interventions such as cancer screening that preclude the development of late-stage disease through early detection are not well studied, and clinical practice guidelines for cancer screening rely solely on recommendations from the general population. Among patients with a prior breast cancer history, disease recurrence after transplantation is a rare but fearful event. Once disease recurs, the risk of death is high. The focus of this review is to present the epidemiology of breast cancer in solid organ transplant recipients, screening and preventive strategies for those who may be at risk, novel genomic profiling for determining tumor progression, and the newer targeted interventions for recipients who have developed breast cancers after solid organ transplantation.

Rediscovering Beta-2 Microglobulin As a Biomarker across the Spectrum of Kidney Diseases

There is currently an unmet need for better biomarkers across the spectrum of renal diseases. In this paper, we revisit the role of beta-2 microglobulin (β₂M) as a biomarker in patients with chronic kidney disease and end-stage renal disease. Prior to reviewing the numerous clinical studies in the area, we describe the basic biology of β₂M, focusing in particular on its role in maintaining the serum albumin levels and reclaiming the albumin in tubular fluid through the actions of the neonatal Fc receptor. Disorders of abnormal β₂M function arise as a result of altered binding of β₂M to its protein cofactors and the clinical manifestations are exemplified by rare human genetic conditions and mice knockouts. We highlight the utility of β₂M as a predictor of renal function and clinical outcomes in recent large database studies against predictions made by recently developed whole body population kinetic models. Furthermore, we discuss recent animal data suggesting that contrary to textbook dogma urinary β₂M may be a marker for glomerular rather than tubular pathology. We review the existing literature about β₂M as a biomarker in patients receiving renal replacement therapy, with particular emphasis on large outcome trials. We note emerging proteomic data suggesting that β₂M is a promising marker of chronic allograft nephropathy. Finally, we present data about the role of β₂M as a biomarker in a number of non-renal diseases. The goal of this comprehensive review is to direct attention to the multifaceted role of β₂M as a biomarker, and its exciting biology in order to propose the next steps required to bring this recently rediscovered biomarker into the twenty-first century.

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.

Cancer and mTOR Inhibitors in Transplant Recipients

Malignancy is the second most common single cause of death observed in organ transplant recipients. The excess cancer risk is related to intensity and duration of immunosuppressive therapy and inversely to recipient age. Immunodeficiency and (chronic/oncogenic) viral infections together constitute a major risk. Nonmelanoma skin cancer, Kaposi sarcoma, and posttransplant lymphoproliferative disease have standardized incidence ratios exceeding 10- or 50-fold. The mammalian target of rapamycin (mTOR) inhibitors, sirolimus and everolimus, are increasingly used after organ transplantation with potential advantages in virus-associated posttransplant malignancies as well as anti-cancer properties. Despite a seemingly clear mechanism of action and solid rationale for their use in cancer therapy, mTORis have met only modest success rates in clinical trials with advanced malignancies except for specific tumors, such as Kaposi sarcoma and mantle cell lymphoma. Because mTORis are primarily cytostatic, not cytotoxic, the observed clinical efficacy is a reflection of disease stabilization rather than tumor regression. Nonmelanoma skin cancers, in particular cutaneous squamous cell carcinoma, have the highest standardized incidence ratios in transplant recipients. Recent meta-analyses and randomized trials on secondary prevention of squamous cell carcinoma observed a reduction in cumulative tumor load, suggesting most benefit to be gained by early conversion to an mTOR inhibitor-based maintenance regime. There is ongoing debate on the mechanisms involved including withdrawal of the carcinogenic effects of calcineurin inhibitors and/or their impact on chronic (oncogenic) viral infections. At present, there is, however, insufficient evidence for the primary use of mTORis as protective agents against most other cancer types.

Thyroid dysfunction and kidney disease: An update

Thyroid hormones influence renal development, kidney hemodynamics, glomerular filtration rate and sodium and water homeostasis. Hypothyroidism and hyperthyroidism affect renal function by direct renal effects as well as systemic hemodynamic, metabolic and cardiovascular effects. Hypothyroidism has been associated with increased serum creatinine and decreased glomerular filtration rate. The reverse effects have been reported in thyrotoxicosis. Most of renal manifestations of thyroid dysfunction are reversible with treatment. Kidney disease may also cause thyroid dysfunction by several mechanisms. Nephrotic syndrome has been associated to changes in serum thyroid hormone concentrations. Different forms of glomerulonephritis and tubulointerstitial disease may be linked to thyroid derangements. A high prevalence of thyroid hormone alteration has been reported in acute kidney injury. Thyroid dysfunction is highly prevalent in chronic kidney disease patients. Subclinical hypothyroidism and low triiodothyronine syndrome are common features in patients with chronic kidney disease. Patients treated by both hemodialysis and peritoneal dialysis, and renal transplantation recipients, exhibit thyroid hormone alterations and thyroid disease with higher frequency than that found in the general population. Drugs used in the therapy of thyroid disease may lead to renal complications and, similarly, drugs used in kidney disorders may be associated to thyroid alterations. Lastly, low thyroid hormones, especially low triiodothyronine levels, in patients with chronic kidney disease have been related to a higher risk of cardiovascular disease and all-cause mortality. Interpretation of the interactions between thyroid and renal function is a challenge for clinicians involved in the treatment of patients with thyroid and kidney disease.

Risk of Renal Cell Carcinoma Among Kidney Transplant Recipients in the United States

Renal cell carcinoma (RCC) is a common malignancy following kidney transplantation. We describe RCC risk and examine RCC risk factors among US kidney recipients (1987-2010). The Transplant Cancer Match Study links the US transplant registry with 15 cancer registries. Standardized incidence ratios (SIRs) were used to compare RCC risk (overall and for clear cell [ccRCC] and papillary subtypes) to the general population. Associations with risk factors were assessed using Cox models. We identified 683 RCCs among 116 208 kidney recipients. RCC risk was substantially elevated compared with the general population (SIR 5.68, 95% confidence interval 5.27-6.13), especially for papillary RCC (SIR 13.3 versus 3.98 for ccRCC). Among kidney recipients, RCC risk was significantly elevated for blacks compared to whites (hazard ratio [HR] 1.50) and lower in females than males (HR 0.56). RCC risk increased with prolonged dialysis preceding transplantation (p-trend < 0.0001). Risk was variably associated for RCC subtypes with some medical conditions that were indications for transplantation: ccRCC risk was reduced with polycystic kidney disease (HR 0.54), and papillary RCC was increased with hypertensive nephrosclerosis (HR 2.02) and vascular diseases (HR 1.86). In conclusion, kidney recipients experience substantially elevated risk of RCC, especially for papillary RCC, and multiple factors contribute to these cancers.

Vertebral bone density associates with coronary artery calcification and is an independent predictor of poor outcome in end-stage renal disease patients

OBJECTIVE

Chronic kidney disease-mineral bone disorder (CKD-MBD) is a major complication of end-stage renal disease (ESRD). Reduced bone mineral density (BMD) is associated with vascular calcification. Here we investigated associations between vertebral bone density (VBD) and coronary artery calcification (CAC), quantified by cardiac computed tomography (CT), and BMD quantified by dual-energy X-ray absorptiometry (DXA), and their relations with mortality.

METHODS

In 231 ESRD patients (median age 56years, 63% males) comprising incident dialysis patients, prevalent peritoneal dialysis patients and recipients of living donor kidney transplant, VBD (Hounsfield units, HUs) and CAC scores (Agatston units, AUs) were quantified by cardiac CT, and, in 143 of the patients, BMD was measured by DXA of total body. Metabolic and inflammation biomarkers potentially linked to CKD-MBD were also analysed.

RESULTS

Patients with low tertile of VBD were older and had more often cardiovascular disease (CVD), and higher HbA1c (non-diabetics), interleukin-6 and CAC score. Low VBD was independently associated with higher CAC score (>100 AUs) after adjustment for age, gender, diabetes, CVD, inflammation and cohorts. In Cox proportional hazards analysis, low VBD was independently associated with all-cause mortality after adjustment for age, gender, diabetes, CVD, inflammation and subjective global assessment (SGA). The root mean-squared error of prediction (RMSE) showed a good degree of association between VBD and BMD evaluated from DXA. In receiver-operator characteristics curve (ROC) analysis, lower VBD was more strongly associated with higher CAC score and all-cause mortality than BMD evaluated from DXA.

CONCLUSIONS

While assessments of BMD by DXA and CT showed good degree of agreement, associations of high CAC, and mortality, with low VBD were stronger than those based on low BMD by DXA. The strong independent associations of low VBD with high CAC score and increased mortality risk suggest that VBD may serve as an important prognosticator in ESRD patients.

Risk of skin cancer in patients on chronic haemodialysis: a nationwide, population-based study in Taiwan

BACKGROUND

Patients on chronic haemodialysis (HD) have a higher incidence of cancer. However, the risk of skin cancer in this population has rarely been investigated.

OBJECTIVES

To investigate the risk of nonmelanoma skin cancer (NMSC) and cutaneous melanoma in patients on chronic HD and to explore the associated risk factors.

METHODS

We performed retrospective cohort and nested case-control studies using records in the Taiwanese National Health Insurance Research Database between 1999 and 2013. The HD cohort included 79 668 incident patients on HD, for whom the standardized incidence ratios (SIRs) for incident NMSC and cutaneous melanoma were determined. In the nested case-control study, patients on HD with NMSC were matched to those without skin cancers. The impact of various factors on the development of NMSC was determined by conditional logistic regression analysis.

RESULTS

Among the 79 668 patients on HD, 248 cases of NMSC and 22 cases of cutaneous melanoma occurred after a mean 4·95 years of follow-up. The SIRs for NMSC and cutaneous melanoma in patients on HD were 1·58 (95% confidence interval 1·39-1·79) and 1·44 (95% confidence interval 0·91-2·19), respectively. Of the patients on HD, a higher risk of NMSC was found in men (1·5-fold), South Taiwan residents (twofold) and patients with uraemic pruritus after long-term antihistamine treatment (1·53-fold). However, the incidence of NMSC was not increased in patients with uraemic pruritus receiving ultraviolet B phototherapy.

CONCLUSIONS

Patients on chronic HD are at higher risk of NMSC. Uraemic pruritus further increases the risk of NMSC, which might be prevented by ultraviolet B phototherapy.

The Nephrologist's Tumor: Basic Biology and Management of Renal Cell Carcinoma

Kidney cancer, or renal cell carcinoma (RCC), is a disease of increasing incidence that is commonly seen in the general practice of nephrology. However, RCC is under-recognized by the nephrology community, such that its presence in curricula and research by this group is lacking. In the most common form of RCC, clear cell renal cell carcinoma (ccRCC), inactivation of the von Hippel-Lindau tumor suppressor is nearly universal; thus, the biology of ccRCC is characterized by activation of hypoxia-relevant pathways that lead to the associated paraneoplastic syndromes. Therefore, RCC is labeled the internist's tumor. In light of this characterization and multiple other metabolic abnormalities recently associated with ccRCC, it can now be viewed as a metabolic disease. In this review, we discuss the basic biology, pathology, and approaches for treatment of RCC. It is important to distinguish between kidney confinement and distant spread of RCC, because this difference affects diagnostic and therapeutic approaches and patient survival, and it is important to recognize the key interplay between RCC, RCC therapy, and CKD. Better understanding of all aspects of this disease will lead to optimal patient care and more recognition of an increasingly prevalent nephrologic disease, which we now appropriately label the nephrologist's tumor.