Gender differences in cancer risk after kidney transplantation

Gender and kidney transplantation

Kidney transplantation provides the best form of kidney replacement therapy with improvement in quality of life and longevity. However, disparity exists in its availability, utilisation and outcomes, not only due to donor availability or financial constraints but also arising from the influence of biological sex and its sociocultural attribute i.e., Gender. Women make up the majority of kidney donors but are less likely to be counselled regarding transpantation, be waitlisted or receive living/deceased donor kidney. Biological differences also contribute to differences in kidney transplantation among the sexes. Women are more likely to be sensitised owing to pregnancy, especially in multiparous individuals, complicating donor compatibility. A heightened immune system in women, evidenced by more autoimmune illnesses, increases the risk of allograft rejection and loss. Differences in the pharmacokinetics of transplant drugs owing to biological variances could also contribute to variability in outcomes. Transgender medicine is also increasingly becoming a relevant topic of study, providing greater challenges in the form of hormonal manipulations and anatomic changes. It is thus important to determine and study transplantation and its nuances in this backdrop to be able to provide relevant sex and gender-specific interventions and design better practices for optimum kidney transplant utilisation and outcomes.

Sex differences in cancer incidence among solid organ transplant recipients

BACKGROUND

Males have 2-3-fold greater risk of cancer than females at most shared anatomic sites, possibly reflecting enhanced immune surveillance against cancer in females. We examined whether these sex differences remained among immunocompromised adults.

METHODS

Using the Transplant Cancer Match (TCM) study, we estimated the male-to-female incidence rate ratio in TCM (M:F IRRTransplant) for 15 cancer sites diagnosed between 1995 and 2017 using Poisson regression. Male to female IRRs in the general population (M:F IRRGP) were calculated using expected cancer counts from the Surveillance, Epidemiology, and End Results Program, standardized to the transplant population on age, race and ethnicity, and diagnosis year. Male to female IRRs were compared using a chi-square test.

RESULTS

Among 343 802 solid organ transplants, 211 206 (61.4%) were among men and 132 596 (38.6%) among women. An excess cancer incidence in males was seen in transplant recipients, but the sex difference was attenuated for cancers of the lip (M:F IRRTransplant: 1.81 vs M:F IRRGP: 3.96; P < .0001), stomach (1.51 vs 2.09; P = .002), colorectum (0.98 vs 1.43; P < .0001), liver (2.39 vs 3.44; P = .002), kidney (1.67 vs 2.24; P < .0001), bladder (2.02 vs 4.19; P < .0001), Kaposi sarcoma (1.79 vs 3.26; P = .0009), and non-Hodgkin lymphoma (1.34 vs 1.64; P < .0001). The M:F IRRTransplant was not statistically different from the M:F IRRGP for other cancer sites.

CONCLUSIONS

Although male solid organ transplant recipients have higher cancer incidence than female recipients, the attenuation in the male to female ratio for many cancers studied relative to the general population might suggest the importance of immunosurveillance, with some loss of advantage in female recipients due to immunosuppression after transplantation.

Temporal trends of de novo urological malignancy in renal transplant recipients without a cancer history: A longitudinal cohort study

BACKGROUND

The incidence of malignancies after successful kidney transplantation has historically been higher than in the general population, with adverse impact on clinical outcomes. However, uncertainty remains as to which cancers occur at what time points after kidney transplantation.

METHODS

We conducted a longitudinal cohort study to investigate the temporal trends and topographic patterns of de novo malignancies to optimize surveillance protocols and improve transplant outcome in renal transplant recipients. Measurement of death and cancer events was performed to calculate the cumulative risk of events of interest.

RESULTS

Between 2000 and 2013, 3169 renal transplant recipients were retrospectively screened; 3035 (96%) of them met eligibility criteria and were evaluated with a follow-up of 27612 person-years. There was suboptimal overall survival and malignancy-free survival in renal transplant recipients compared to reference groups (HR: 1.65; 95% CI: 1.50-1.82; p < .001; HR: 2.33; 95% CI: 2.04-2.66; p < .001, respectively). Among renal transplant recipients, urological malignancies were predominant (57.5%), followed by digestive tract malignancies (21.4%). The cancer risks of the urinary bladder and upper urinary tract were lower in male subjects (HR: .48; 95% CI: .33-.72; p < .001; HR: .34; 95% CI: .20-.59; p < .001, respectively). The temporal trends of urological malignancies among renal transplant recipients were expressed in a bimodal pattern, with M-shaped peaks at 3 and 9 years, with gender disparity.

CONCLUSIONS

In renal transplant recipients, cancer occurrences are shown as M-shaped twin peaks. Our study highlights that specific customized 'targeted' strategies for cancer surveillance programs are required to optimize posttransplant care.

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.

Changes over time in the causes of death with a functioning graft in kidney transplantation recipients

INTRODUCTION

Death with a functioning graft (DWFG) is the most frequent cause of loss of kidney transplantation (KT).

OBJECTIVE

To analyze the evolution of the causes of DWFG and the frequency of the types of cancer causing DWFG.

METHODS

Retrospective study of KT in Andalusia from 1984 to 2018. We analyzed the evolution according to eras (1984-1995; 1996-2007; 2008-2018) and according to post-transplant period (early death: first year post-KT; late death: after first year post-KT).

RESULTS

A total of 9905 KT were performed, registering 1861 DWFG. The most frequent causes were cardiovascular disease (25.1%), infections (21.5%) and cancer (19.9%). In early death we did not observe changes, and infections were always the main cause. In late death, cardiovascular death decreased (1984-1995: 35.2%, 1996-2007: 22.6%, 2008-2018: 23.9%), but infections (1984-1995: 12.5%, 1996-2007: 18.3%, 2008-2018: 19.9%) and, above all, cancer-related deaths increased (1984-1995: 21.8%, 1996-2007: 29%, 2008-2018: 26.8%) (P < .001). In the multivariable analysis for late death due to cardiovascular disease, recipient age, retransplantation, diabetes, and the first period were risk factors, while the risk of late death due to cancer and infections was associated with recent eras. In the first year after transplantation, the most frequent neoplasia causing DWFG was post-transplant lymphoproliferative disease, and after the first year, it was lung cancer, without differences when it was analyzed by eras.

CONCLUSIONS

Despite the greater comorbidity of the recipients, cardiovascular deaths have decreased. Cancer has been the main cause of late death in recent years. Lung cancer is the most frequent malignancy that causes DWFG in our transplant patients.

Malignancies in adult kidney transplant candidates and recipients: current status

Posttransplant malignancies, particularly recurrent and de novo, in solid organs including kidney transplant recipients (KTRs) are a significant complication associated with substantial mortality, largely attributed to long-term immunosuppression necessary to maintain allograft tolerance. Older age at transplantation and oncogenic virus infection along with pretransplant malignancies are among the main factors contributing to the risk of cancer in this population. As the mean age of transplant candidates rises, the rate of transplant recipients with pretransplant malignancies also increases. The eligibility criteria for transplantation in patients with prior cancer have recently changed. The overall risk of posttransplant malignancies is at least double after transplantation including KTRs relative to the general population, most pronounced for skin cancers associated with UV radiation and virally-mediated tumors. The risk of renal cell carcinoma is specifically increased in the kidney transplant population. The therapy of cancer in transplant patients is associated with risk of higher toxicity, and graft rejection and/or impairment, which poses a unique challenge in the management. Reduction of immunosuppression and the use of mTOR inhibitors are common after cancer diagnosis, although optimal immunosuppression for transplant recipients with cancer remains undefined. Suboptimal cancer treatment contributing to a worse prognosis has been reported for malignancies in this population. In this article, we focus on the prevalence and outcomes of posttransplant malignancies, cancer therapy including a short overview of immunotherapy, cancer screening and prevention strategies, and immunosuppression as a cancer risk factor. The 2020/2021 recommendations of the Kidney Diseases Improving Global Outcome (KDIGO) and American Society of Transplantation (AST) for transplant candidates with a history of cancer are presented.

An overview of the efficacy and safety of everolimus in adult solid organ transplant recipients

As the risk of graft loss due to acute rejection has declined, the goal of post-transplant management has switched to long-term preservation of organ function. Minimizing calcineurin inhibitor (CNI)-related nephrotoxicity is a key component of this objective. Everolimus is a mammalian target of rapamycin inhibitor/proliferation-signal inhibitor with potent immunosuppressive and anti-proliferative effects. It has been widely investigated in large randomized clinical studies that have shown it to have similar anti-rejection efficacy compared with standard-of-care regimens across organ transplant indications. With demonstrated potential to facilitate the reduction of CNI therapy and preserve renal function, everolimus is an alternative to the current standard-of-care CNI-based regimens used in de novo and maintenance solid organ transplantation recipients. Here, we provide an overview of the evidence from the everolimus clinical study program across kidney, liver, heart, and lung transplants, as well as other key data associated with its use in CNI reduction strategies in adult transplant recipients.

Sex differences in cancer risk and outcomes after kidney transplantation

Kidney transplant recipients (KTRs) experience a two- to four-fold increased risk of developing and dying from cancer compared with the general population. High cancer risk results from the interaction of both modifiable and non-modifiable factors. This mapping review explores the impact of sex disparity on cancer's increased incidence and mortality after kidney transplantation (KT). In terms of age, population-based studies indicate that younger recipients of both sexes experience a higher risk of cancer, but this is more pronounced in young women. On the contrary, older men are more likely to be diagnosed with cancer, although their increased risk is not statistically significant compared with the general population. Regarding cancer type, studies show an increased risk of Kaposi sarcoma, gynecologic and lung cancer in women, and bladder and kidney cancer in men. Immune-related cancers such as pos-transplant lymphoproliferative disorders and melanoma are increased in both sexes. Mortality also shows differences between sexes. Although cancer is the second cause of death in both male and female KTRs, studies show higher overall mortality in men and elderly recipients. However, the relative risk of cancer mortality compared with the general population is higher at a younger age, with disparate results regarding sex. Female KTRs appear to die at a younger age than males when compared with the general population. Differences in cancer rates by sex after renal transplantation need further studies. A better understanding of sex-specific differences in cancer epidemiology after KT could help nephrologists to better address pre-transplant counseling, to establish early surveillance programs, and to plan modifiable risk factors such as immunosuppression.

De-novo malignancies after kidney transplantation: A long-term observational study

Background

De-novo malignancies after kidney transplantation represent one major cause for mortality after transplantation. However, most of the studies are limited due to small sample size, short follow-up or lack of information about cancer specific mortality.

Methods

This long-term retrospective analysis included all adult patients with complete follow-up that underwent kidney transplantation between 1995 and 2016 at our centre. All patients with diagnosis of malignancy excluding non-melanoma skin cancer (NMSC) were identified and a matched control group was assigned to the kidney transplant recipients with post-transplant malignancies.

Results

1417 patients matched the inclusion criteria. 179 malignancies posttransplant were diagnosed in 154 patients (n = 21 with two, n = 2 patients with three different malignancies). Mean age at cancer diagnosis was 60.3±13.3 years. Overall incidence of de-novo malignancies except NMSC was 1% per year posttransplant. Renal cell carcinoma was the most common entity (n = 49, incidence 4.20 per 1000 patient years; cancer specific mortality 12%), followed by cancer of the gastro-intestinal tract (n = 30, 2.57; 50%), urinary system (n = 24, 2.06; 13%), respiratory system (n = 18, 1.54; 89%), female reproductive system (n = 15, 1.29; 13%), posttransplant lymphoproliferative disorders and haematological tumours (n = 14, 1.20; 21%), cancers of unknown primary (n = 7, 0.60 100%) and others (n = 22, 1.89; 27%). Male sex, re-transplantation and time on dialysis were associated with de-novo malignancies after transplantation.

Conclusion

De-novo malignancies continue to be a serious problem after kidney transplantation. To improve long-term outcome after Kidney transplantation, prevention and cancer screening should be more tailored and intensified.

Cancer Risks in Solid Organ Transplant Recipients: Results from a Comprehensive Analysis of 72 Cohort Studies

Understanding the cancer risks in different transplant recipients helps early detection, evaluation, and treatment of post-transplant malignancies. Therefore, we performed a meta-analysis to determine the cancer risks at multiple sites for solid organ transplant recipients and their associations with tumor mutation burden (TMB), which reflects the immunogenicity. A comprehensive search of PubMed, Web of Science, EMBASE, Medline, and Cochrane Library was conducted. Random effects models were used to calculate the standardized incidence ratios (SIRs) versus the general population and determine the risks of different cancers. Linear regression (LR) was used to analyze the association between the SIRs and TMBs. Finally, seventy-two articles met our criteria, involving 2,105,122 solid organ transplant recipients. Compared with the general population, solid organ transplant recipients displayed a 2.68-fold cancer risk (SIR 2.68; 2.48–2.89; P <.001), renal transplant recipients displayed a 2.56-fold cancer risk (SIR 2.56; 2.31–2.84; P <.001), liver transplant recipients displayed a 2.45-fold cancer risk (SIR 2.45; 2.22–2.70; P <.001), heart and/or lung transplant recipients displayed a 3.72-fold cancer risk (SIR 3.72; 3.04–4.54; P <.001). The correlation coefficients between SIRs and TMBs were 0.68, 0.64, 0.59, 0.79 in solid organ recipients, renal recipients, liver recipients, heart and/or lung recipients, respectively. In conclusion, our study demonstrated that solid organ transplant recipients displayed a higher risk of some site-specific cancers, providing individualized guidance for clinicians to early detect, evaluate, and treat cancer among solid organ transplantation recipients. In addition, the increased cancer risk of solid organ transplant recipients is associated with TMB, suggesting that iatrogenic immunosuppression may contribute to the increased cancer risk in transplant recipients. (PROSPERO ID CRD42020160409).

Nutrition Trends in Patients Over the Long Term After Kidney Transplantation

OBJECTIVES

Nutritional behaviors may exert important influence on morbidity and graft function in patients after kidney transplantation (KT). Nutritional status is closely related to potential risk factors of developing posttransplant complications, including diabetes mellitus, weight gain, and negative effects on immunosuppressive therapy. The aim of this study was to assess the dietary intake in patients after KT.

DESIGN AND METHODS

Nutritional intake of 154 (61 women and 93 men) patients was assessed based on a questionnaire regarding food intake (proteins, fats, carbohydrates, cholesterol, sugar, phosphorus, calorific value) within 3 working days preceding the routine outpatient posttransplant visit. Patient medical history, concomitant medications, and estimated glomerular filtration rate (eGFR) was obtained from medical charts.

RESULTS

The mean age (years) ± SD of patients was 51.9 ± 14.1. The patients were evaluated 94 ± 67 months after KT, with a median eGFR of 53 (range, 41.2-64.1) mL/min/1.73 m². Sixty-two percent of patients had increased body mass index values. The mean total energy intake was 2159.4 ± 551.9 kcal/day. The patients reported elevated salt (8.5 ± 2.4 g per day) and fat intake (99.4 ± 3.2 g per day) including 57% saturated fatty acids. The patients consumed products containing high amounts of sugars (108.2 ± 107.0 g per day), carbohydrates (238.3 ± 64.3 g per day), and cholesterol (303.6 ± 11.1 mg per day). The diet among kidney recipients consisted predominantly of fats, meat, cured meat, and sweets.

CONCLUSIONS

The nutritional behaviors of patients after KT are in most cases poor. Improvement of eating habits in these patients seems to be a simple method to preserve kidney function over the long term.

Pelvic radiation therapy with volumetric modulated arc therapy and intensity-modulated radiotherapy after renal transplant: A report of 3 cases

Aim

Describe characteristics and outcomes of three patients treated with pelvic radiation therapy after kidney transplant.

Background

The incidence of pelvic cancers in kidney transplant (KT) recipients is rising. Currently it is the leading cause of death. Moreover, treatment is challenging because anatomical variants, comorbidities, and associated treatments, which raises the concern of using radiotherapy (RT). RT has been discouraged due to the increased risk of urethral/ureteral stricture and KT dysfunction.

Materials and methods

We reviewed the electronic health records and digital planning system of patients treated with pelvic RT between December 2013 and December 2018 to identify patients with previous KT.

Cases description

We describe three successful cases of KT patients in which modern techniques allowed full standard RT for pelvic malignances (2 prostate and 1 vaginal cancer) with or without elective pelvic nodal RT, without allograft toxicity at short and long follow-up (up to 60 months).

Conclusion

When needed, RT modern techniques remain a valid option with excellent oncologic results and acceptable toxicity. Physicians should give special considerations to accomplish all OAR dose constraints in the patient's specific setting. Recent publications recommend KT mean dose <4 Gy, but graft proximity to CTV makes this unfeasible. We present 2 cases where dose constraint was not achieved, and to a short follow-up of 20 months renal toxicity has not been documented. We recommend the lowest possible mean dose to the KT, but never compromising the CTV coverage, since morbimortality from recurrent or progressive cancer disease outweighs the risk of graft injury.