Racial/ethnic differences in cancer risk after kidney transplantation

Role of standard HLA mismatch in modifying associations between non-pharmacologic risk factors and solid organ malignancy after kidney transplantation

BACKGROUND

Human leukocyte antigen mismatch(es) (HLA-mm) between donors and recipients has not been extensively studied either as a risk factor for solid organ malignancy (SOM) or as a modifier of associations between nonpharmacologic risk factors and SOM in kidney transplant recipients (KTRs).

METHODS

In a secondary analysis from a previous study, 166,256 adult KTRs in 2000-2018 who survived the first 12 months post-transplant free of graft loss or malignancy were classified into 0, 1-3, and 4-6 standard HLA-mm cohorts. Multivariable cause-specific Cox regressions analyzed the risks of SOM and all-cause mortality (ac-mortality) in 5 years following the first KT year. Comparisons of associations between SOM and risk factors in HLA mismatch cohorts were made by estimating the ratios of adjusted hazard ratios.

RESULTS

Compared with 0 HLA-mm, 1-3 HLA-mm was not associated, and 4-6 HLA-mm was equivocally associated with increased risk of SOM [hazard ratio, (HR) = 1.05, 95%, confidence interval (CI) = 0.94-1.17 and HR = 1.11, 95% CI = 1.00-1.34, respectively]. Both 1-3 HLA-mm and 4-6 HLA-mm were associated with increased risk of ac-mortality compared with 0 HLA mm [hazard ratio (HR) = 1.12, 95%, Confidence Interval (CI) = 1.08-1.18) and (HR = 1.16, 95% CI = 1.09-1.22), respectively]. KTR's history of pre-transplant cancer, age 50-64, and >/=65 years were associated with increased risks of SOM and ac-mortality in all HLA mismatch cohorts. Pre-transplant dialysis >2 years, diabetes as the primary renal disease, and expanded or standard criteria deceased donor transplantation were risk factors for SOM in the 0 and 1-3 HLA-mm cohorts and of ac-mortality in all HLA-mm cohorts. KTRs male sex or history of previous kidney transplant was a risk factor for SOM in the 1-3 and 4-6 HLA-mm cohorts and of ac-mortality in all HLA-mm cohorts.

CONCLUSION

Direct association between SOM and the degree of HLA mismatching is equivocal and limited to the 4-6 HLA-mm stratum; however, the degree of HLA mismatching has significant modifying effects on the associations between specific nonpharmacologic risk factors and SOM in KTRs.

Chronic kidney diseases and the risk of colorectal cancer: A systematic review and meta-analysis

Objective

We conducted this review to offer a comprehensive search and up-to-date overview of the currently available information about the probability risk of colorectal cancer among chronic kidney disease patients.

Method

We performed a systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews (PRISMA) and meta-analysis guidelines. We identified, reviewed, and extracted from Scopus, PubMed, EMBASE, and Komaki Databases for research publications on chronic kidney disease and colorectal cancer published between February 2016 and January 2023. We meta-analyzed the prevalence of colorectal cancer with chronic kidney disease. We ran a random effect meta-regression. Risk-of-bias assessment was evaluated using the Newcastle-Ottawa Scale. The systematic review was registered with PROSPERO (CRD42023400983).

Results

The risk of CRC in chronic kidney diseases was reported in 50 research studies, which included 4,337,966 people from 16 different countries. SIR of CRC was obtained from 14 studies and showed a significant relationship between CRC with CKD patients, with a pooled SIR of 1.33; 95% CI (1.30-1.36), with higher heterogeneity (Q = 121.82, P < 0.001, and I2 = 86.9%). Metaregression showed that there was no significant correlation between the risk of CRC and the proportion of males or age.

Conclusion

Overall, this study shows that patients with chronic kidney disease have a significantly increased risk of colorectal cancer. More studies with larger sample sizes, and robust surveillance are needed.

Risk of Prostate Cancer in Chronic Kidney Disease Patient: A Meta-Analysis using Observational Studies

Background

Both clinical and experimental findings demonstrated a rise in prostate cancer in chronic renal illness. However, the clinical data associated with CKD was not looked at the context of prostate cancer. The study aims to investigate prostate cancer risk in CKD patients using clinical data via systemic review and meta-analysis.

Materials and Methods

Using pertinent pairing keywords, I carried out a thorough exploration of PubMed/MEDLINE and Web of Science. The pooled HR with 95% CI of the considered clinical findings was estimated involving the general inverse variance outcome type. With RevMan 5.3, the total pooled estimate meta-analysis was evaluated utilizing the random effects model.

Results

Total of six findings were considered for this analysis, with a total of 2,430,246 participants. The age and mean follow-up of the included patients and studies ranged from 55 to 67.4 years and 10.1 to 12 years, respectively. The meta-analysis showed no significant risk of prostate cancer among CKD patients (HR: 0.92; 95% CI: 0.60-1.41; P = 0.70). The results from subgroup analysis based on eGFR levels ranged ≥30-59 ml/min per 1.73 m2 and also found no significant risk of prostate cancer among CKD patients (HR: 1.04; 95% CI: 0.92-1.18; P = 0.52). Here I did not report statistical heterogeneity found (Q = 0.56, I2 = 0%, P = 0.87). As per the Newcastle-Ottawa scale, the included studies suggested good quality.

Conclusion

The results suggest no significant risk of developing prostate cancer among CKD patients. Therefore, well-designed prospective cohort studies with stages of CKD and clear predefined prior history and causative factors are needed to support the present evidence strongly.

Post‐kidney transplant cancers: Racial and ethnic differences in sun‐exposed skin versus non‐sun‐exposed anogenital skin

BACKGROUND

Transplant recipients have a 2- to 4-fold increased risk of developing malignancies over the general population. Cancer is the second most common cause of death for recipients. The magnitude of the risk depends on the cancer type and increases in viral-related malignancies. Skin cancer is the most common. However, data in most cancer registries is limited to cutaneous melanomas, thereby limiting the epidemiologic examination of cancer risk in non-melanoma skin cancer. Our goal was to evaluate post-kidney transplant cancer cases and sites in our population to guide screening recommendations.

METHODS

Between 2009 and 2015, a retrospective study of adult kidney recipients transplanted at East Carolina University was conducted. The first cancer diagnosis after transplant through February 18, 2020, was captured and analyzed. Patient demographics, cancer sites, and histological diagnoses were analyzed and compared. p16 immunohistochemistry was used as a surrogate marker for high-risk human papillomavirus (HPV) infection.

RESULTS

Retrospectively, kidney transplant recipients were analyzed (N = 439), the majority were non-Hispanic Black (NHB) individuals, 312 (71.1%), and 127 (28.9%) were non-Hispanic White (NHW) individuals. Of these, 59 (13.4%) developed a posttransplant malignancy, with the majority on sun-exposed skin found in NHW. NHB had all anogenital/mucosa skin cancers on non-sun-exposed skin. Of these detected in NHB, all were squamous cell carcinomas, with five out of six (83.3%) being positive for p16.

CONCLUSIONS

Posttransplant malignancy differed significantly by race, site, and potential source of etiology. The majority of malignancies are likely explained by acceleration of precursor lesions from prior exposure to ultraviolet rays or HPV.

Changes in cancer incidence and outcomes among kidney transplant recipients in the United States over a thirty-year period

Recipients of kidney transplants have elevated cancer risk compared with the general population. Improvements over time in transplant care and cancer treatment may have affected incidence and outcomes of cancer among recipients of kidney transplant. To evaluate this, we used linked United States transplant and cancer registry data to study 101,014 adult recipients of kidney transplants over three decades (1987-1996, 1997-2006, 2007-2016). Poisson regression was used to assess trends in incidence for cancer overall and seven common cancers. Associations of cancer with risk of death-censored graft failure (DCGF) and death with functioning graft (DWFG) were evaluated with Cox regression. We also estimated absolute risks of DCGF and graft failure following cancer for recipients transplanted in 2007-2016. There was no significant change in the incidence of cancer overall or for six common cancers in recipients across the 1987-2016 period. Only the incidence of prostate cancer significantly decreased across this period after multivariate adjustment. Among recipients of kidney transplants with non-Hodgkin lymphoma, there were significant declines over time in elevated risks for DCGF and DWFG but no significant changes for other combined cancers. For recipients transplanted in the most recent period (2007-2016), risks following cancer diagnosis remained high, with 38% experiencing DWFG and 14% graft failure within four years of diagnosis. Absolute risk of DWFG was especially high following lung cancer (78%), non-Hodgkin lymphoma (38%), melanoma (35%), and colorectal cancer (49%). Thus, across a 30-year period in the United States, there was no overall change in cancer incidence among recipients of kidney transplants. Despite improvements for non-Hodgkin lymphoma, cancer remains a major cause of morbidity and mortality.

Patient and allograft outcomes after kidney transplant for the Indigenous patients in the United States

Background

The objective is to assess cardiovascular (CV), malignancy, infectious, graft outcomes and tacrolimus levels for the Indigenous patients compared to Whites after kidney transplant (KTx).

Methods

165 Indigenous and 165 White patients matched for the KTx year at Mayo Clinic Arizona from 2007–2015 were studied over a median follow-up of 3 years. Propensity score was calculated to account for baseline differences.

Results

Compared to Whites, Indigenous patients had the following characteristics: younger age, more obesity, diabetes, hypertension, and required dialysis prior to KTx (p<0.01). Indigenous patients had longer hospital stay for KTx, shorter follow-up and lived further from the transplant center (p<0.05). 210 (63.6%) received deceased donor KTx and more Whites received a living donor KTx compared to Indigenous patients (55.2% vs 17.6%, p<0.0001). Post-KTx, there was no difference in the CV event rates. The cumulative incidence of infectious complications was higher among the Indigenous patients (HR 1.81, p = 0.0005, 48.5% vs 38.2%, p = 0.013), with urinary causes as the most common. Malignancy rates were increased among Whites (13.3% vs 3.0%, p = 0.001) with skin cancer being the most common. There was a significant increase in the dose normalized tacrolimus level for the Indigenous patients compared to Whites at 1 months, 3 months, and 1 year post-KTx. After adjustment for the propensity score, there was no statistical difference in infectious or graft outcomes between the two groups but the mean number of emergency room visits and hospitalizations after KTx was significantly higher for Whites compared to Indigenous patients.

Conclusions

Compared to Whites, Indigenous patients have similar CV events, graft outcomes and infectious complications after accounting for baseline differences.

Risk of renal cancer in patients with inflammatory bowel disease: A pooled analysis of population-based studies

BACKGROUND

Currently, newer epidemiological studies report the association between inflammatory bowel disease (IBD) and risk of renal cancer (RCa). Thus, we conducted a meta-analysis to determine whether IBD patients were associated with RCa risk.

METHODS

Various medical databases were searched from inception to April 2020. Standardized incidence ratio (SIR) or relative risk (RR) with corresponding 95% confidence intervals (CIs) were pooled. The meta-analysis was completed by STATA version 14.2.

RESULTS

A total of 421 articles were identified, and 11 studies met the inclusion criteria. Data from 9 cohort studies showed a significantly increased risk of RCa in IBD patients (pooled SIR: 1.53; 95%CI: 1.25-1.80; I² = 42.4%), especially for patients with Crohn's disease (CD) (pooled SIR: 1.95; 95%CI: 1.45-2.44; I² = 39.9%). We did not observe a significantly increased risk of RCa in patients with ulcerative colitis (UC) (pooled SIR: 1.31; 95%CI: 0.94-1.67; I² = 48.0%) when compared to the background population. Only 2 case-control studies reported the results of RCa risk, showing no significant difference between IBD group and IBD-free group (pooled RR: 1.64; 95%CI: 0.52-5.22; I² = 77.9%).

CONCLUSIONS

Our findings indicate that IBD patients with special reference to CD patients have a significantly higher risk of RCa. Further studies are warranted to enable definite conclusions to be drawn.

Understanding racial disparities in renal cell carcinoma incidence: estimates of population attributable risk in two US populations

PURPOSE

Renal cell carcinoma (RCC) incidence is higher among black than white Americans. The reasons for this disparity remain unclear.

METHODS

We calculated race- and sex-specific population attributable risk percentages (PAR%) and their 95% confidence intervals (CI) for hypertension and chronic kidney disease (CKD) among black and white subjects ≥  50 years of age from the US Kidney Cancer Study (USKC; 965 cases, 953 controls), a case-control study in Chicago and Detroit, and a nested case-control study in the Kaiser Permanente Northern California health care network (KPNC; 2,162 cases, 21,484 controls). We also estimated PAR% for other modifiable RCC risk factors (cigarette smoking, obesity) in USKC.

RESULTS

In USKC, the PAR% for hypertension was 50% (95% CI 24-77%) and 44% (95% CI 25-64%) among black women and men, respectively, and 29% (95% CI 13-44%) and 27% (95% CI 14-39%) for white women and men, respectively. In KPNC, the hypertension PAR% was 40% (95% CI 18-62%) and 23% (95% CI 2-44%) among black women and men, and 27% (95% CI 20-35%) and 19% (95% CI 14-24%) among white women and men, respectively. The PAR% for CKD in both studies ranged from 7 to 10% for black women and men but was negligible (<1%) for white subjects. In USKC, the PAR% for current smoking was 20% and 8% among black and white men, respectively, and negligible and 8.6% for black and white women, respectively. The obesity PAR% ranged from 12 to 24% across all race/sex strata.

CONCLUSIONS

If the associations found are causal, interventions that prevent hypertension and CKD among black Americans could potentially eliminate the racial disparity in RCC incidence (hypothetical black:white RCC incidence ratio of 0.5).

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.

Risk of Colorectal Cancer in Chronic Kidney Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Association between chronic kidney disease and colorectal cancer (CRC) remains unclear.

GOALS

To assess the risk of CRC in patients with various chronic kidney diseases before and after kidney transplantation.

STUDY

Electronic databases were searched for cohort studies assessing the risk of CRC in patients with chronic kidney diseases. The primary outcome was the risk of CRC among studies that reported the risk as standardized incidence rate (SIR).

RESULTS

Fifty-four studies, including 1,208,767 patients that reported the incidence of CRC in chronic kidney diseases were identified. SIR of CRC were obtained from 17 retrospective cohort studies. Among the 3 studies (4 reports) that included chronic kidney disease patients without kidney transplantation, there was a significant increased risk of CRC (pooled SIR 1.18) (95% confidence interval, 1.01-1.37; P=0.033). High heterogeneity was seen (I=85.6%), and metaregression showed that there were positive correlations between the risk of CRC and the proportions of males, age and follow-up period. Among the 15 studies (17 reports) that included postkidney transplant patients, the pooled SIR was significantly increased at 1.40 (95% confidence interval, 1.15-1.71; P=0.00080). High heterogeneity was seen (I=88.9%), and metaregression showed that the follow-up period correlated with the risk of CRC.

CONCLUSIONS

In the present systematic review and meta-analysis, we demonstrated that patients with chronic kidney disease, regardless of a history of transplant, have a significant increased risk of CRC. A more intensive surveillance for CRC is required in this population.

De novo malignancy in organ transplant recipients in Taiwan: a nationwide cohort population study

Organ transplant recipients appear to have a higher risk of de novo malignancy. The aim of the study was designed to estimate cancer risk in heart, lung, kidney and liver transplant recipients. The cohort study used the Taiwan National Health Insurance Research Database (1996-2011) and followed the outcomes of organ recipients until 2012. De novo cancer and mortality rates after organ transplantation were evaluated using standardized incidence ratios, excess absolute risks of cancer, and standardized mortality ratios in recipients were compared with those in the general population. We identified 40, 231, 2, and 115 patients who developed cancer after heart, kidney, lung, and liver transplantation, which corresponded to a cancer incidence of 878.4, 1101.2, 728.9, and 1361.4 cases per 100,000 person-years, respectively. In heart, kidney, lung, and liver recipients, the overall standardized incidence ratios were 1.65 (1.21-2.24), 3.33 (2.93-3.79), 1.82 (0.45-7.27) and 3.37 (2.81-4.05) and the overall standardized mortality ratios were 5.45 (4.96-5.98), 1.47 (1.34-1.61), 8.92 (7.10-11.20), and 3.83 (3.48-4.20), respectively. These results reveal a three-fold increase in de novo cancer risk in organ transplant patients compared with the general population. This study illustrated the importance of de novo malignancy after organ transplantation.

Risk Factors for Melanoma in Renal Transplant Recipients

Importance

Melanoma risk factors and incidence in renal transplant recipients can inform decision making for both patients and clinicians.

Objective

To determine risk factors and characteristics of renal transplant recipients who develop melanoma.

Design, Setting, and Participants

This cohort study of a large national data registry used a cohort of renal transplant recipients from the United States Renal Data System (USRDS) database from the years 2004 through 2012. Differences in baseline characteristics between those who did and did not develop melanoma were examined, and a survival analysis was performed. Patients with renal transplants who received a diagnosis of melanoma according to any inpatient or outpatient claim associated with a billing code for melanoma were included. A history of pretransplant melanoma, previous kidney transplantation, or transplantation after 2012 or before 2004 were exclusion criteria. The data analysis was conducted from 2015 to 2016.

Exposure

Receipt of a renal transplant.

Main Outcomes and Measures

Incidence and risk factors for melanoma.

Results

Of 105 174 patients (64 151 [60.7%] male; mean [SD] age, 49.6 [15.3] years) who received kidney transplants between 2004 and 2012, 488 (0.4%) had a record of melanoma after transplantation. Significant risk factors for developing melanoma vs not developing melanoma included older age among recipients (mean [SD] age, 60.5 [10.2] vs 49.7 [15.3] years; P < .001) and donors (42.6 [15.0] vs 39.2 [15.1] years; P < .001), male sex (71.5% vs 60.7%; P < .001), recipient (96.1% vs 66.5%; P < .001) and donor (92.4% vs 82.9%; P < .001) white race, less than 4 HLA mismatches (44.9% vs 37.1%; P = .001), living donors (44.7% vs 33.7%; P < .001), and sirolimus (22.3% vs 13.2%; P < .001) and cyclosporine (4.9% vs 3.2%; P = .04) therapy. Risk factors significant on survival analysis included older recipient age (hazard ratio [HR] per year, 1.06; 95% CI, 1.05-1.06; P < .001), recipient male sex (HR, 1.53; 95% CI, 1.25-1.88; P < .001), recipient white race, living donors (HR, 1.35; 95% CI, 1.11-1.64; P = .002), and sirolimus (HR, 1.54; 95% CI, 1.22-1.94; P < .001) and cyclosporine (HR, 1.93; 95% CI, 1.24-2.99; P = .004) therapy. The age-standardized relative rate of melanoma in USRDS patients compared with Surveillance, Epidemiology, and End Results patients across all years was 4.9. A Kaplan-Meier estimate of the median time to melanoma among those patients who did develop melanoma was 1.45 years (95% CI, 1.31-1.70 years).

Conclusions and Relevance

Renal transplant recipients had greater risk of developing melanoma than the general population. We believe that the risk factors we identified can guide clinicians in providing adequate care for patients in this vulnerable group.

Overall Graft Loss Versus Death-Censored Graft Loss: Unmasking the Magnitude of Racial Disparities in Outcomes Among US Kidney Transplant Recipients

BACKGROUND

Black kidney transplant recipients experience disproportionately high rates of graft loss. This disparity has persisted for 40 years, and improvements may be impeded based on the current public reporting of overall graft loss by US regulatory organizations for transplantation.

METHODS

Longitudinal cohort study of kidney transplant recipients using a data set created by linking Veterans Affairs and US Renal Data System information, including 4918 veterans transplanted between January 2001 and December 2007, with follow-up through December 2010. Multivariable analysis was conducted using 2-stage joint modeling of random and fixed effects of longitudinal data (linear mixed model) with time to event outcomes (Cox regression).

RESULTS

Three thousand three hundred six non-Hispanic whites (67%) were compared with 1612 non-Hispanic black (33%) recipients with 6.0 ± 2.2 years of follow-up. In the unadjusted analysis, black recipients were significantly more likely to have overall graft loss (hazard ratio [HR], 1.19; 95% confidence interval [95% CI], 1.07-1.33), death-censored graft loss (HR, 1.67; 95% CI, 1.45-1.92), and lower mortality (HR, 0.83; 95% CI, 0.72-0.96). In fully adjusted models, only death-censored graft loss remained significant (HR, 1.38; 95% CI, 1.12-1.71; overall graft loss [HR, 1.08; 95% CI, 0.91-1.28]; mortality [HR, 0.84; 95% CI, 0.67-1.06]). A composite definition of graft loss reduced the magnitude of disparities in blacks by 22%.

CONCLUSIONS

Non-Hispanic black kidney transplant recipients experience a substantial disparity in graft loss, but not mortality. This study of US data provides evidence to suggest that researchers should focus on using death-censored graft loss as the primary outcome of interest to facilitate a better understanding of racial disparities in kidney transplantation.

Cancer-related outcomes in kidney allograft recipients in England versus New York State: a comparative population-cohort analysis between 2003 and 2013

It is unclear whether cancer‐related epidemiology after kidney transplantation is translatable between countries. In this population‐cohort study, we compared cancer incidence and all‐cause mortality after extracting data for every kidney‐alone transplant procedure performed in England and New York State (NYS) between 2003 and 2013. Data were analyzed for 18,493 and 11,602 adult recipients from England and NYS respectively, with median follow up 6.3 years and 5.5 years respectively (up to December 2014). English patients were more likely to have previous cancer at time of transplantation compared to NYS patients (5.6% vs. 3.5%, P < 0.001). Kidney allograft recipients in England versus NYS had increased cancer incidence (12.3% vs. 5.9%, P < 0.001) but lower all‐cause mortality during the immediate postoperative stay (0.7% vs. 1.0%, P = 0.011), after 30‐days (0.9% vs. 1.8%, P < 0.001) and after 1‐year post‐transplantation (3.0% vs. 5.1%, P < 0.001). However, mortality rates among patients developing post‐transplant cancer were equivalent between the two countries. During the first year of follow up, if patients had an admission with a cancer diagnosis, they were more likely to die in both England (Odds Ratio 4.28 [95% CI: 3.09–5.93], P < 0.001) and NYS (Odds Ratio 2.88 [95% CI: 1.70–4.89], P < 0.001). Kidney allograft recipients in NYS demonstrated higher hazard ratios for developing kidney transplant rejection/failure compared to England on Cox regression analysis. Our analysis demonstrates significant differences in cancer‐related epidemiology between kidney allograft recipients in England versus NYS, suggesting caution in translating post‐transplant cancer epidemiology between countries.

De Novo Malignancies After Transplantation: Risk and Surveillance Strategies

De novo malignancies are one of the leading causes of late mortality after liver and kidney transplantation. Nonmelanoma skin cancer is the most common malignancy, followed by posttransplant lymphoproliferative disorder and solid organ tumors. Immunosuppression is a key factor for cancer development, although many other transplant-related and traditional risk factors also play a role. In this review, the authors summarize risk factors and outcomes of frequently encountered de novo malignancies after liver and kidney transplantation to stratify recipients at highest risk. Future efforts in prospectively validated, cost-effective surveillance strategies that improve survival of these complex patients are greatly needed.

Racial disparities in overall survival among renal cell carcinoma patients with young age and small tumors

We examined the overall survival of a population‐based cohort of black and white patients with renal cell carcinoma (RCC) to better understand the paradox of poorer RCC survival despite more frequent diagnosis at lower stage among blacks. Renal cell carcinoma patients (699 white, 252 black) diagnosed between 2002 and 2007 in metropolitan Detroit were followed for vital status in the Detroit Surveillance, Epidemiology and End Results (SEER) registry. Hazard ratios (HR) of death for black versus white race and 95% confidence intervals (CIs) were calculated using Cox proportional hazard models stratified by demographic and prognostic factors, and in models successively adjusted for clinical factors, comorbidities, and socioeconomic factors. Mean follow‐up time was 88.4 months for white patients and 89.6 months for black patients (P = 0.49), with 202 white deaths and 89 black deaths (P = 0.06). While black race was weakly associated with poorer overall survival (P = 0.053), black patients <65 years at diagnosis or with tumors <4 cm in size had significantly poorer survival than their white counterparts (HR = 1.46, 95% CI 1.06–2.01 and HR = 2.15, 95% CI 1.51–3.06, respectively). The racial disparities within these two subgroups were minimally affected by adjustment for clinical/treatment factors (HR = 1.49, 95% CI 1.01–2.19 and HR = 1.95, 95% CI 1.27–2.99), but were substantially reduced when renal‐relevant comorbidities were added (HR = 1.30, 95% CI 0.89–1.91 and HR = 1.76, 95% CI 1.16–2.66). After further adjustment for socioeconomic factors, the survival disparities were essentially null (HR = 1.14, 95% CI 0.71–1.85 and HR = 1.15, 95% CI 0.67–1.98). In this population‐based sample of RCC patients, younger black patients and those with small tumors had poorer overall survival than whites. The disparity was explained primarily by racial differences in renal‐relevant comorbidities, particularly chronic renal failure, and socioeconomic deprivation. Future research should focus on younger patients and those with smaller tumors to better understand how these factors may contribute to the survival disparity.

[Incidence of skin and non-skin cancers in Afro-Caribbean renal transplant recipients: Guadeloupe data from 2004 to 2011]

BACKGROUND

Cancer is the main complication of transplantation surgery. The literature concerning renal transplant recipients among the Afro-Caribbean population is scant. The aim of this study was to determine the incidence of cancer in these patients, with the secondary objective being to identify predisposing factors for cancer.

PATIENTS AND METHODS

This was an epidemiological and retrospective study that included all Guadeloupians of phototype V-VI undergoing renal transplantation from 01/01/2004 to 31/12/2011. Skin cancer screening was performed before transplantation and during an annual dermatological consultation following transplantation. Screening for non-cutaneous cancers was guided by clinical symptoms or by the results of the screening examinations recommended in the current guidelines. At the study time-point (31/12/2011), all patients were examined by a dermatologist.

RESULTS

One hundred and two patients were included : 42 women and 60 men (mean age: 52.1±11.6 years at transplantation). Eight cancers were diagnosed. The cumulative incidence of cancer was 7.8% at 3 years. Three factors were associated with more rapid onset of cancer: personal history or familial history of cancer, and genital lesion induced by HPV.

CONCLUSION

Our results suggest a low incidence of cancer in Afro-Caribbean renal transplant patients. Personal or family history of cancer and HPV-induced genital lesions would appear to accelerate the onset of cancer in this population.

Chronic kidney disease and risk of renal cell carcinoma: differences by race

BACKGROUND

The incidence of renal cell carcinoma in the United States differs by race/ethnicity. To better understand these disparities, we conducted a nested case-control study investigating renal cell carcinoma risk factors across racial/ethnic groups within the Kaiser Permanente Northern California health care network.

METHODS

Our study included 3136 renal cell carcinoma cases (2152 whites, 293 blacks, 425 Hispanics, and 255 Asians) diagnosed between 1998 and 2008 and 31031 individually matched controls (21478 whites, 2836 blacks, 4147 Hispanics, and 2484 Asians). Risk of renal cell carcinoma was assessed in relation to smoking status, body mass index (BMI), hypertension, and chronic kidney disease. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression, and population attributable risk (PAR) to estimate by race the proportion of cases attributable to hypertension and chronic kidney disease.

RESULTS

The association between chronic kidney disease and renal cell carcinoma differed markedly by race (Pinteraction < 0.001), with associations observed among blacks (OR = 10.4 [95% CI = 6.0-17.9]), Asians (5.1 [2.2-11.7]), and Hispanics (2.3 [1.1-4.6]) but not whites (1.1 [0.6-1.9]). Hypertension, high BMI, and smoking were associated with renal cell carcinoma, but findings generally did not differ by race. Relative to other racial/ethnic groups, blacks had the highest proportion of renal cell carcinoma incidence attributable to hypertension and chronic kidney disease (combined, PAR = 37%; hypertension only, PAR = 27%; chronic kidney disease, PAR = 10%).

CONCLUSIONS

Our findings suggest that hypertension and chronic kidney disease likely have contributed to the observed excess in renal cell carcinoma incidence among blacks compared with whites.