Uptake of Cancer Screening Tests Among Recipients of Solid Organ Transplantation

A Global Survey of Self-Reported Cancer Screening Practices by Health Professionals for Kidney Transplant Candidates and Recipients

Cancer is a major cause of morbidity and mortality in kidney transplant recipients. Health professionals have a critical role in promoting cancer screening participation. From March 2023 to February 2024, an online survey was distributed to kidney transplant health professionals globally to assess their screening practices. We compared their reported screening practices to recommended guidelines and analyzed factors associated with these practices. We received 97 responses, and most were nephrologists (70%), and around 80% recommended breast, colorectal, and cervical cancer screening for kidney transplant candidates and recipients. About 85% recommended lung cancer screening for higher-risk individuals. Skin cancer screening recommendations varied from 69% for transplant candidates and 84% for recipients. Self-reported cervical cancer screening practices were most concordant with recommended guidelines, followed by breast and skin cancers. Barriers reported included a lack of cancer screening awareness (28%), perceived financial constraints (35%), and deficient structured cancer screening systems (51%). Professionals from high-income countries were more likely to advise screening than those from lower-middle-income countries, with odds ratios ranging from 2.9 to 12.3. Most health professionals reported recommending cancer screening for kidney transplant candidates and recipients. However, recommendations were influenced by costs and service delivery gaps within health systems.

Cervical Cancer Screening Utilization among Kidney Transplant Recipients, 2001 to 2018

BACKGROUND

Kidney transplant recipients (KTR) have elevated risks of cervical precancers and cancers and guidelines recommend more frequent cervical cancer screening exams. However, little is known about current trends in cervical cancer screening in this unique population. We described patterns in the uptake of cervical cancer screening exams among female KTRs and identified factors associated with screening utilization.

METHODS

This retrospective cohort study included female KTRs between 20 and 65 years old, with Texas Medicare fee-for-service coverage, who received a transplant between January 1, 2001, and December 31, 2017. We determined the cumulative incidence of receiving cervical cancer screening post-transplant using ICD-9, ICD-10, and CPT codes and assessed factors associated with screening utilization, using the Fine and Gray model to account for competing events. Subdistribution hazard models were used to assess factors associated with screening uptake.

RESULTS

Among 2,653 KTRs meeting the inclusion and exclusion criteria, the 1-, 2-, and 3-year cumulative incidences of initiating a cervical cancer screening exam post-transplant were 31.7% [95% confidence interval (CI), 30.0%-33.6%], 48.0% (95% CI, 46.2%-49.9%), and 58.5% (95% CI, 56.7%-60.3%), respectively. KTRs who were 55 to 64 years old (vs. <45 years old) and those with a higher Charlson Comorbidity Score post-transplant were less likely to receive cervical cancer screening post-transplant.

CONCLUSIONS

Cervical cancer screening uptake is low in the years immediately following a kidney transplant.

IMPACT

Our findings highlight a need for interventions to improve cervical cancer screening utilization among kidney transplant recipients. See related In the Spotlight, p. 1554.

Immunosuppression and cancer risk in kidney transplant recipients: A retrospective cohort study

We assessed whether contemporary immunosuppression agents were associated with cancer among kidney transplant recipients (KTR), and if this association varied by age and sex. We studied a retrospective province-wide cohort of primary KTR (1997-2016). Employing multivariable Cox models, we estimated associations of cumulative doses of prednisone, mycophenolate and tacrolimus administered over the past 10 years, lagged by 2 years, with the incidence of primary malignant neoplasms (PMN). We assessed interactions with age and sex. To assess the impact of exposure recency, we used weighted cumulative exposure (WCE) modeling. Among 1064 KTR, 108 (10.2%) developed PMN over median follow-up of 73 months (interquartile range: 32-120). Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of 0.96 (0.64-1.43), 1.34 (0.96-1.86), and 1.06 (0.88-1.29) were estimated for cumulative daily doses of prednisone (5 mg), mycophenolate (1000 mg), and tacrolimus (2 mg) administered continuously over the past 10 years, respectively. PMN risk associated with cumulative tacrolimus exposure was modified by age (interaction p = .035) and was more pronounced in 15-year and 30-year-old KTR (aHRs of 1.57 [1.08-2.28] and 1.31 [1.03-1.66], respectively) in comparison to older KTR. PMN risk increase associated with higher cumulative mycophenolate dose was more pronounced in females (aHR = 1.86 [1.15-3.00]) than in males (aHR = 1.16 [0.74-1.81]; interaction p = .131). WCE analyses suggested increased PMN risk the higher the mycophenolate doses taken 5-10 years ago. A trend toward increased PMN risk with long-term mycophenolate exposure, particularly in females, and more pronounced risk with long-term tacrolimus exposure in younger KTR, identify opportunities for tailored immunosuppression to mitigate cancer risk.

Access to Cancer Care: Prevention and Screening for Females Post Kidney Transplantation Around the World

Kidney transplantation offers recipients superior outcomes and improved quality of life compared with dialysis. However, the need for ongoing immunosuppression places recipients at increased risk of certain forms of cancer. Screening and early detection of precancerous lesions are one of the few proven ways to lower the risk of cancer morbidity and mortality in the transplant population. Women have additional barriers to cancer screening services globally, especially in low- and middle-income countries as well as within certain disadvantaged groups in high-income countries. There is a dearth of published data on screening guidelines and policies on post-transplant malignancy in female recipients. It is vital that health care providers and patients are educated regarding the risks of cancer at all post-transplant stages and that the recommended screening policies are adhered to in order to reduce associated morbidity and mortality in this at-risk group.

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.

Variations in Risk of Cancer and Death From Cancer According to Kidney Allograft Function, Graft Loss, and Return to Dialysis

BACKGROUND

Cancer incidence and mortality may change with varying kidney allograft function and after graft loss. We aimed to quantify cancer incidence and mortality during periods with a functioning graft and after graft loss.

METHODS

We included all adult Australians aged 20 and above who commenced kidney replacement therapy between 1982 and 2014 using data from Australia and New Zealand Dialysis and Transplant Registry. We calculated the standardized incidence ratios and standardized mortality ratios (standardized against the Australian general population) for dialysis patients and transplant recipients during periods with a functioning graft and after graft loss.

RESULTS

A total of 44 765 dialysis patients without transplants, 13 443 with first kidney transplants, 2951 after first graft loss, 1010 with second transplants, and 279 after second graft loss were followed for 274 660 patient-years. Cancer incidence and mortality (per 100 000 patient-years) were 1564 and 760 in dialysis patients, 1564 and 689 in recipients of first transplants, 1188 and 390 after first graft loss, 1525 and 693 after second transplants, and 1645 and 779 after second graft loss. Cancer standardized incidence ratios and standardized mortality ratios (95% confidence intervals) were 1.15 (1.11-1.20) and 1.29 (1.21-1.36) for dialysis patients, 2.03 (1.94-2.13) and 2.50 (2.33-2.69) for recipients following their first transplant, 1.55 (1.29-1.85) and 1.40 (1.00-1.90) after first graft loss, 2.18 (1.79-2.63) and 3.00 (2.23-3.96) for second transplants, 2.59 (1.56-4.04) and 3.82 (1.75-7.25) after second graft loss.

CONCLUSIONS

In kidney transplant recipients, cancer incidence and mortality are highest during periods with a functioning graft and remained higher than in the general population even after graft loss.

Mortality among solid organ transplant recipients with a pretransplant cancer diagnosis

Little is known about the outcomes among solid organ transplant recipients with a pretransplant cancer diagnosis. We used linked data from the Scientific Registry of Transplant Recipients with 33 US cancer registries. Cox proportional hazards models assessed associations of pretransplant cancer with overall mortality, cancer-specific mortality, and development of a new posttransplant cancer. Among 311 677 recipients, the presence of a single pretransplant cancer was associated with increased overall mortality (adjusted hazard ratio [aHR], 1.19; 95% CI, 1.15-1.23) and cancer-specific mortality (aHR, 1.93; 95% CI, 1.76-2.12); results for 2+ pretransplant cancers were similar. Cancer-specific mortality was not significantly increased for uterine, prostate, or thyroid cancers (aHRs were 0.83, 1.22, and 1.54, respectively) but strongly elevated for lung cancer and myeloma (aHRs were 3.72 and 4.42, respectively). A pretransplant cancer diagnosis was also associated with increased risk of developing posttransplant cancer (aHR, 1.32; 95% CI, 1.23-1.40). Among 306 recipients whose cancer death was confirmed by cancer registry data, 158 deaths (51.6%) were from a de novo posttransplant cancer and 105 (34.3%) from the pretransplant cancer. Pretransplant cancer diagnoses are associated with increased mortality after transplantation, but some deaths are related to posttransplant cancers and other causes. Improved candidate selection and cancer screening and prevention may reduce mortality in this population.

Emerging Concepts in Managing Malignancy in Kidney Transplant Patients

Cancer remains a significant cause of morbidity and mortality in kidney transplant recipients, due to long-term immunosuppression. Salient issues to consider in decreasing the burden of malignancy among kidney transplant recipients include pretransplant recipient evaluation, post-transplant screening and monitoring, and optimal treatment strategies for the kidney transplant recipients with cancer. In this review, we address cancer incidence and outcomes, approaches to cancer screening and monitoring pretransplant and post-transplant, as well as treatment strategies, immunosuppressive management, and multidisciplinary approaches in the kidney transplant recipients with cancer.

Cancer Screening in Solid Organ Transplant Recipients: A Focus on Screening Liver, Lung, and Kidney Recipients for Cancers Related to the Transplanted Organ

Over the last few decades, the life expectancy of solid organ transplant recipients (SOTRs) has improved significantly. With SOTRs living longer, more recipients are dying from cancer. There is a reported 2- to 3-fold increased risk of cancer-specific mortality in SOTRs compared with the general population. Cancer in an SOTR can be de novo, recurrent, or donor-derived. Cancer screening in this population is crucial, as early detection and treatment may improve outcomes. In the absence of randomized controlled trials dedicated to SOTRs, clinicians rely on clinical practice guidelines from regional and national transplant societies; however, these may vary considerably across jurisdictions and transplanted organ. At present, no widely accepted consensus exists for cancer screening protocols in SOTRs, particularly with regard to screening for malignancy related to transplanted organ. Some SOTRs may be at higher risk of malignancies within the allograft. This is particularly the case in lung and liver recipients, though less common in kidney recipients who are at increased risk of developing renal cell cancer in their native kidneys. This increased risk has not been uniformly incorporated into screening recommendations for SOTRs. In this review, we summarize the cancer screening recommendations for SOTRs from various transplant organizations based on transplanted organ. This review also discusses the complexity and controversies surrounding screening of cancer in the allograft and future avenues to improve cancer detection in this context. More studies specific to SOTRs are required to form generalizable and evidence-based cancer screening guidelines, particularly with respect to cancer screening in the allograft.

Periodic screening for breast and cervical cancer in women with diabetes: a population-based cohort study

PURPOSE

Diabetes is associated with poorer cancer outcomes. Screening for breast and cervical cancer is recommended by clinical guidelines; however, utilization of these tests in people with diabetes has been unclear due to methodological limitations in the evidence base. We used administrative data to determine the association between diabetes and the rates of becoming up-to-date with periodic breast and cervical cancer screening over a 20-year period.

METHODS

Healthcare databases from Ontario, Canada, were linked to assemble two population-based cohorts of 50-70 and 21-70 year-olds between 1994 and 2011, eligible for breast and cervical cancer screening, respectively. Using age as the time scale, multivariable recurrent events models were implemented to examine the association between the presence of diabetes and the rates of becoming up-to-date with the recommended cancer screenings.

RESULTS

In each of the breast and cervical cancer screening cohorts, there were, respectively, 1,516,302 (16% had diabetes at baseline) and 4,751,220 (9.5% had diabetes at baseline) screen-eligible women. In multivariable models, prevalent diabetes (duration ≥ 2 years) was associated with lower rates of becoming up-to-date with cervical (hazard ratio, HR 0.85, 95% confidence interval, CI 0.84-0.85) and breast (HR 0.94, CI 0.93-0.94) cancer screening, compared to no diabetes.

CONCLUSIONS

Having diabetes is associated with decreased rates of becoming up-to-date with two recommended periodic cancer screenings, with a bigger reduction in the rates of becoming up-to-date with cervical cancer screening. Greater attention to cervical cancer preventive services is needed in women with diabetes.

Influence of chronic comorbidities on periodic colorectal cancer screening participation: A population-based cohort study

Guidelines recommend regular screening for colorectal cancer (CRC). We examined the effects of chronic comorbidities on periodic CRC testing. Using linked healthcare databases from Ontario, Canada, we assembled a population-based cohort of 50-74-year olds overdue for guideline-recommended CRC screening between April 1, 2004 and March 31, 2016. We implemented multivariable recurrent events models to determine the association between comorbidities and the rate of becoming up-to-date with periodic CRC tests. The cohort included 4,642,422 individuals. CRC testing rates were significantly lower in persons with renal disease on dialysis (hazard ratio, HR 0.66, 95% confidence interval, CI 0.63 to 0.68), heart failure (HR 0.75, CI 0.75 to 0.76), respiratory disease (HR 0.84, CI 0.83 to 0.84), cardiovascular disease (HR 0.85, CI 0.84 to 0.85), diabetes (HR 0.86, 95% CI 0.86 to 0.87) and mental illness (HR 0.88, CI 0.87 to 0.88). There was an inverse association between the number of medical conditions and the rate of CRC testing (5 vs. none: HR 0.30, CI 0.25 to 0.36; 4 vs. none: HR 0.48, CI 0.47 to 0.50; 3 vs. none: HR 0.59, CI 0.58 to 0.60; 2 vs. none: HR 0.72, CI 0.71 to 0.72; 1 vs. none: HR 0.85, CI 0.84 to 0.85). Having both medical and mental comorbidities was associated with lower testing rates than either type of comorbidity alone (HR 0.72, CI 0.71 to 0.72). In summary, chronic comorbidities present a barrier to periodic guideline-recommended CRC testing. Exploration of cancer prevention gaps in these populations is warranted.

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.

Low participation in preventative health measures in a cohort of liver transplant recipients: A cross-sectional analysis

BACKGROUND

Despite high rates of infection and malignancy post-solid organ transplant, there are little data on patient participation in preventative health care.

METHODS

We conducted a cross-sectional survey of post-liver transplant patients to evaluate insight into transplant-associated infective and neoplastic risks, and receipt of vaccination and cancer surveillance in accordance with Australian and local institution-specific guidelines. Descriptive analyses were used to assess characteristics potentially influencing adherence.

RESULTS

Of 219 patients surveyed, adherence to bowel cancer surveillance was significantly reduced in those distant from transplantation compared with those recently transplanted (95.8% if transplanted ≤ 5 years ago vs. 68.3% if transplanted > 5 years ago, P < .001). Skin cancer surveillance participation with annual physician-directed examination was low (42.9%), particularly in younger patients (29.5% in < 50yo vs. 48.1% in ≥ 50yo, P = .01), who were also less adherent to vaccination recommendations (72.1% in < 50yo vs. 87.3% in ≥ 50yo, P = .008).

CONCLUSIONS

This is the first analysis of preventative healthcare participation in a cohort of Australian liver transplant recipients, revealing concerning adherence to bowel and skin cancer surveillance recommendations. Major interventions to avoid preventable disease in this high-risk cohort are warranted.

Post-transplant malignancies in pediatric organ transplant recipients

The majority of cancer diagnoses in pediatric solid organ transplant recipients (SOTRs) are post-transplantation lymphoproliferative disorders (PTLD) or skin cancers. However, pediatric SOTRs are also at significantly elevated risk for multiple other solid and hematological cancers. The risks of specific cancers vary by transplanted organ, underlying disease, and immunosuppression factors. More than one-quarter of pediatric SOTRs develop cancer within 30 years of transplantation and their risk of solid cancer is 14 times greater than the general population. Pediatric SOTRs are at significantly higher risk of cancer-associated death. Improving patient survival among pediatric SOTRs puts them at risk of adult epithelial cancers associated with environmental carcinogenic exposures. Vaccination against oncogenic viruses and avoidance of excessive immunosuppression may reduce the risk of solid cancers following transplantation. Patient and family education regarding photoprotection is an essential component of skin cancer prevention. There is significant variability in cancer screening recommendations for SOTRs and general population approaches are typically not validated for transplant populations. An individualized approach to cancer screening should be developed based on estimated cancer risk, patient life expectancy, and screening test performance.

Medication adherence is associated with an increased risk of cancer in kidney transplant recipients: a cohort study

Background

Nonadherence to posttransplant immunosuppressive medication is associated with increased rates of rejection and graft loss, yet it is unknown to what degree ideal adherence is associated with the sequelae of overimmunosuppression. Specifically, we questioned whether excellent adherence increased the posttransplant cancer risk.

Methods

Between August 1998 and August 2006, 195 consenting kidney transplant recipients had electronic monitoring of theirimmunosuppressive medication adherence.

Results

Based on their average quantitative adherence to a single immunosuppressant drug over the first 6 months posttransplant, recipients were grouped into adherence tertiles (highest, >97.9% adherence; middle, 91-97.8%; lowest, <91%). The cumulative incidence of cancer was calculated for patients in each tertile, treating death as a competing risk. The association between adherence and cancer rate was calculated after adjusting for recipient risk factors, using a competing risk proportional hazards model. The median duration of follow-up was 10.1 years. The 10-year estimated cumulative cancer incidence was 59.4% in the most adherent, 36.1% in the middle group and 38.1% in the least adherent group (P = 0.006). Excluding nonmelanocytic skin cancers, cancer incidence remained significantly higher in the highest adherence group (P = 0.002).

Conclusions

These data provide additional support for the need to individualize immunosuppression to minimize both rejection and immunosuppressive drug-related complications including cancer.

Nephrologists' perspectives on cancer screening in patients with chronic kidney disease: An interview study

AIM

Patients with chronic kidney disease (CKD) have an increased risk of cancer compared with the general population. Despite this, there is considerable variability in cancer screening practices among nephrologists that may reflect uncertainties about the benefits and harms of screening, the additional costs, and competing priorities among the complex issues that patients are confronted with. We aimed to describe nephrologists' perspectives and approaches to cancer screening in CKD.

METHODS

Semi-structured interviews were conducted with 29 nephrologists from 15 units across Australia and New Zealand. Interviews were transcribed and thematically analyzed.

RESULTS

Five themes were identified: empowering patients to make informed decisions (respecting patient preferences, communicating evidence-based recommendations, creating awareness of consequences, preparing for transplantation); justifiable risk taking (avoiding undue consequences in vulnerable populations, balancing the costs and benefits, warranted by long term immunosuppression, assurance of reasonable survival gains); ambiguity of evidence in supporting decisions (absence of standardized recommendations, limited transferability of population-based data); depending on a shared multidisciplinary approach (collaboration with primary health care, access to coordinated skin cancer clinics); and prioritizing current or imminent complications.

CONCLUSION

Nephrologists approach decisions about cancer screening in patients with CKD based on patient preferences, assessment of risk, justifiable survival gains, and current health priorities. Evidence-based guidelines, communication frameworks and specialist clinics may support informed and shared decision making about cancer screening in CKD.

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.

Gynecologic cancers and solid organ transplantation

Solid organ transplant (SOT) recipients have an approximately 2-fold greater risk of developing and dying from a malignancy compared to the general population. Among the gynecologic cancers, including uterine, cervical, vaginal, vulvar, and ovarian, the HPV-related cancers are known to increase among women posttransplant compared to women in the general population, but less is known about the risk of uterine and ovarian cancers. This review provides an overview of the epidemiology of gynecologic cancers after solid organ transplantation, as well as the pathophysiology, management, and specific risk factors associated with these cancers. Closer surveillance for cervical cancers is warranted and larger studies are needed to assess whether and how uterine and ovarian cancers are associated with excess incidence and mortality. Such studies may lead to improvements in screening, prevention, and treatment before and after transplantation.

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.

Mortality risk after cancer diagnosis in kidney transplant recipients: the limitations of analyzing hospital administration data alone

Administrative data are frequently used for epidemiological studies but its usefulness to analyze cancer epidemiology after kidney transplantation is unclear. In this retrospective population-based cohort study, we identified every adult kidney-alone transplant performed in England (2003-2014) using administrative data from Hospital Episode Statistics. Results were compared to the hospitalized adult general population in England to calculate standardized incidence and mortality ratios. Data were analyzed for 19,883 kidney allograft recipients, with median follow-up 6.0 years' post-transplantation. Cancer incidence was more common after kidney transplantation compared to the general population in line with published literature (standardized incidence ratio 2.47, 95% CI: 2.34-2.61). In a Cox proportional hazards model, cancer development was associated with increasing age, recipients of deceased kidneys, frequent readmissions within 12 months post-transplant and first kidney recipients. All-cause mortality risk for kidney allograft recipients with new-onset cancer was significantly higher compared to those remaining cancer-free (42.0% vs. 10.3%, respectively). However, when comparing mortality risk for kidney allograft recipients to the general population after development of cancer, risk was lower for both cancer-related (standardized mortality ratio 0.75, 95% CI: 0.71-0.79) and noncancer-related mortality (standardized mortality ratio 0.90, 95% CI: 0.85-0.95), which contradicts reported literature. Although some plausible explanations are conceivable, our analysis likely reflects the limitations of administrative data for analyzing cancer data. Future studies require record linkage with dedicated cancer registries to acquire more robust and accurate data relating to cancer epidemiology after transplantation.