Sirolimus and secondary skin-cancer prevention in kidney transplantation

Human Beta-papillomavirus infection and keratinocyte carcinomas

Although the role of oncogenic human Alpha-papillomaviruses (HPVs) in the development of mucosal carcinomas at different body sites (eg cervix, anus, oropharynx) is fully recognized, a role for HPV in keratinocyte carcinomas (KCs; basal and squamous cell carcinomas) of the skin is not yet clear. KCs are the most common cancers in Caucasians, with the major risk factor being ultraviolet (UV) light exposure. A possible role for Beta-HPV types (BetaPV) in the development of KC was suggested several decades ago, supported by a number of epidemiological studies. Our current review summarizes the recent molecular and histopathological evidence in support of a causal association between BetaPV and the development of KC, and outlines the suspected synergistic effect of viral gene expression with UV radiation and immune suppression. Further insights into the molecular pathways and protein interactions used by BetaPV and the host cell is likely to extend our understanding of the role of BetaPV in KC.

[Delayed wound healing during therapy of cutaneous graft-versus-host disease with everolimus]

Graft-versus-host-disease (GvHD) is despite improvement in transplantation medicine the major cause for morbidity and mortality after allogeneic stem cell transplantation. We describe a patient with chronic cutaneous GvHD who developed massive skin ulcerations after changing the immunosuppressive therapy to a mammalian target of rapamycin (mTOR)-inhibitor.

Skin cancer in solid organ transplant recipients: are mTOR inhibitors a game changer?

While immunosuppressive agents are necessary to prevent the rejection of transplanted organs, and are a great medical success story for protecting against early allograft loss, graft and patient survival over the long term are diminished by side effects from these same drugs. One striking long-term side effect is a high rate of skin cancer development. The skin cancers that develop in transplant recipients tend to be numerous, as well as particularly aggressive, and are therefore a major contributor to morbidity and mortality in transplant recipients. An apparent reason for the high incidence of skin cancer likely relates to suppression of immune surveillance mechanisms, but other more direct effects of certain immunosuppressive drugs are also bound to contribute to cancers of UV-exposed skin. However, over the past few years, evidence has emerged to suggest that one class of immunosuppressants, mammalian target of rapamycin (mTOR) inhibitors, could potentially inhibit skin tumour formation through a number of mechanisms that are still being studied intensively today. Therefore, in light of the high skin cancer incidence in transplant recipients, it follows that clinical trials have been conducted to determine if mTOR inhibitors can significantly reduce these post-transplant skin malignancies. Here, the problem of post-transplant skin cancer will be briefly reviewed, along with the possible mechanisms contributing to this problem, followed by an overview of the relevant clinical trial results using mTOR inhibitors.

Sirolimus use and cancer incidence among US kidney transplant recipients

Sirolimus has anti-carcinogenic properties and can be included in maintenance immunosuppressive therapy following kidney transplantation. We investigated sirolimus effects on cancer incidence among kidney recipients. The US transplant registry was linked with 15 population-based cancer registries and national pharmacy claims. Recipients contributed sirolimus-exposed time when sirolimus claims were filled, and unexposed time when other immunosuppressant claims were filled without sirolimus. Cox regression was used to estimate associations with overall and specific cancer incidence, excluding nonmelanoma skin cancers (not captured in cancer registries). We included 32,604 kidney transplants (5687 sirolimus-exposed). Overall, cancer incidence was suggestively lower during sirolimus use (hazard ratio [HR] = 0.88, 95% confidence interval [CI] = 0.70-1.11). Prostate cancer incidence was higher during sirolimus use (HR = 1.86, 95% CI = 1.15-3.02). Incidence of other cancers was similar or lower with sirolimus use, with a 26% decrease overall (HR = 0.74, 95% CI = 0.57-0.96, excluding prostate cancer). Results were similar after adjustment for demographic and clinical characteristics. This modest association does not provide strong evidence that sirolimus prevents posttransplant cancer, but it may be advantageous among kidney recipients with high cancer risk. Increased prostate cancer diagnoses may result from sirolimus effects on screen detection.

Skin cancer evaluation in transplant patients: a physician opinion survey with recommendations

BACKGROUND

Non-melanoma skin cancer is the most common malignancy in transplant patients. However, routine skin cancer evaluation is currently not the standard of care.

OBJECTIVE

To investigate the current barriers among transplant physicians to skin cancer screening in their patients. To provide recommendations for appropriate routine skin surveillance.

METHODS

A web-based survey was conducted among Baylor, Dallas transplant physicians. Thirty-seven of 46 responses were received, and 13 physicians (28%) were classified as "high screeners."

RESULTS

The univariate analysis revealed three main barriers including the perception of difficulty in seeing a dermatologist (p = 0.017), skin cancer evaluation is not an important aspect of transplant care (p = 0.038), and thirdly, the belief that there is insufficient evidence to warrant universal skin cancer screening in transplant patients (p = 0.013). The fully adjusted multivariable analysis resulted in two significant conclusions; the most important predictor was the perceived lack of medical evidence for skin cancer screening.

LIMITATIONS

The small sample size and all responses being from the same institution in Texas.

CONCLUSION

The dermatologic evidence for regular skin cancer screening in transplant patients needs dissemination to our transplant colleagues. This is a significant practice gap which can be appropriately closed by integrating dermatologists into the transplant team.

Effect of sirolimus on malignancy and survival after kidney transplantation: systematic review and meta-analysis of individual patient data

OBJECTIVE

To examine risk of malignancy and death in patients with kidney transplant who receive the immunosuppressive drug sirolimus.

DESIGN

Systematic review and meta-analysis of individual patient data.

DATA SOURCES

Medline, Embase, and the Cochrane Central Register of Controlled Trials from inception to March 2013.

ELIGIBILITY

Randomized controlled trials comparing immunosuppressive regimens with and without sirolimus in recipients of kidney or combined pancreatic and renal transplant for which the author was willing to provide individual patient level data. Two reviewers independently screened titles/abstracts and full text reports of potentially eligible trials to identify studies for inclusion. All eligible trials reported data on malignancy or survival.

RESULTS

The search yielded 2365 unique citations. Patient level data were available from 5876 patients from 21 randomized trials. Sirolimus was associated with a 40% reduction in the risk of malignancy (adjusted hazard ratio 0.60, 95% confidence interval 0.39 to 0.93) and a 56% reduction in the risk of non-melanoma skin cancer (0.44, 0.30 to 0.63) compared with controls. The most pronounced effect was seen in patients who converted to sirolimus from an established immunosuppressive regimen, resulting in a reduction in risk of malignancy (0.34, 0.28 to 0.41), non-melanoma skin cancer (0.32, 0.24 to 0.42), and other cancers (0.52, 0.38 to 0.69). Sirolimus was associated with an increased risk of death (1.43, 1.21 to 1.71) compared with controls.

CONCLUSIONS

Sirolimus was associated with a reduction in the risk of malignancy and non-melanoma skin cancer in transplant recipients. The benefit was most pronounced in patients who converted from an established immunosuppressive regimen to sirolimus. Given the risk of mortality, however, the use of this drug does not seem warranted for most patients with kidney transplant. Further research is needed to determine if different populations, such as those at high risk of cancer, might benefit from sirolimus.

Incidence and risk factors for skin cancer following lung transplantation

BACKGROUND

Relative to other solid-organ transplantations, limited studies characterize skin cancer among lung-transplant recipients.

OBJECTIVE

We sought to assess the cumulative incidence, tumor burden, and risk factors for skin cancer among patients with lung transplantation.

METHODS

Medical records of patients at Mayo Clinic who had undergone lung transplantation between 1990 and 2011 were reviewed (N = 166).

RESULTS

At 5 and 10 years posttransplantation the cumulative incidence was 31% and 47% for any skin cancer, 28% and 42% for squamous cell carcinoma, 12% and 21% for basal cell carcinoma, and 53% and 86% for death, respectively. Four patients died of metastatic squamous cell carcinoma. The cumulative incidence for a subsequent skin cancer of the same type 4 years after an initial skin cancer was 85% and 43% for squamous and basal cell carcinoma, respectively. Increasing age, male gender, skin cancer history, and more recent year of transplantation were associated with increased risk of skin cancer posttransplantation. Sirolimus was not associated with decreased risk, nor did voriconazole show an increased risk for skin cancer.

LIMITATIONS

Retrospective and tertiary single-center design of the study is a limitation.

CONCLUSIONS

Skin cancers frequently occur in lung-transplant recipients. The risk of subsequent skin cancer is increased substantially in patients who develop a skin cancer after their transplantation.

[Modern immunosuppression after solid organ transplantation]

The one common factor in solid organ transplantation is the need for lifelong maintenance immunosuppression. Drug regimens after organ transplantation typically comprise a combination of different immunosuppressive drugs. In most cases a triple drug regimen with different mechanisms of action is used. The aim is to improve both patient and graft survival while minimizing potential side effects of immunosuppressive medication. The basis of most immunosuppressive regimens is calcineurin inhibitors in combination with mycophenolic acid. There are various stages of immunosuppression after solid organ transplantation involving induction therapy, initial and long-term maintenance therapy. In each phase an individual combination of immunosuppressants is set up depending on the risk profile of the individual patient to prevent transplant rejection and organ loss. Based on these considerations, concepts of calcineurin inhibitor or steroid reduction have been established in transplant medicine in recent years. The key role in terms of development of new immunosuppressive strategies is taken by kidney transplantation, the most common solid organ transplantation performed.

Malignant and noninvasive skin tumours in renal transplant recipients

Background. Transplant recipients require immunosuppression to prevent graft rejection. This conveys an increased risk of malignancy, particularly skin tumours. There is a need for up-to-date data for the South of England. Method. Pathology records were reviewed for 709 kidney transplant recipients on immunosuppression at our hospital from 1995 to 2008. Skin tumours were recorded/analysed. Results. Mean age at transplant was 46 years. Mean length of follow-up was 7.2 years and total follow-up was 4926 person-years. 53 (7.5%) patients (39/458 (8.5%) males and 14/251 (5.6%) females) developed ≥1 skin malignancy. Cumulative incidences of 4.0%, 7.5%, and 12.2% were observed for those with <5, <10, and ≥10 years follow-up, respectively. The rate was 45 tumours per 1000 person-years at risk. Additionally, 21 patients (3.0%) only had noninvasive tumours. 221 malignant skin tumours were found: 50.2% were SCCs, 47.1% BCCs, and 2.7% malignant melanomas. Mean years to first tumour were 5.8. Mean number of tumours per patient was 4, with mean interval of 12 months. Conclusions. Despite changes in transplantation practice during the time since the last data were published in this region, these findings are similar to previous studies. This adds to the evidence allowing clinicians to inform patients in this region of their risk.

Risk of metabolic complications in kidney transplantation after conversion to mTOR inhibitor: a systematic review and meta-analysis

Mammalian target of rapamycin (mTOR) inhibitors have been used in transplantation with the hope of minimizing calcineurin inhibitor (CNI)-induced nephrotoxicity. However, mTOR inhibitors are also associated with a range of side effects, including metabolic complications. We aimed to determine the risks of metabolic complications after the conversion from CNI to mTOR inhibitor postkidney transplant. A systematic search in PubMed up to September 2013 identified nine relevant trials (a total of 2323 patients). The primary end points were the relative risks (RRs) of new-onset diabetes after transplant (NODAT) and hypercholesterolemia. The overall RRs of NODAT and hypercholesterolemia associated with mTOR inhibitors were 1.32 (95% confidence interval [CI] 0.92-1.87) and 2.15 (95% CI 1.35-3.41), respectively, compared with CNI-based regimen. Subgroup analyses revealed no differences in the incidence of NODAT or hypercholesterolemia between sirolimus- versus everolimus-based regimen, or between early versus late conversion. Analyses of secondary outcomes revealed a higher risk of acute rejection, proteinuria and anemia, but no difference in the risk of opportunistic infections after mTOR inhibitor conversion. In conclusion, the conversion from CNI to mTOR inhibitor in low-to-moderate risk kidney transplant recipients was associated with nonsignificant trend toward increased risk of NODAT and significant increase in hypercholesterolemia, acute rejection, proteinuria and anemia.

Skin cancers after liver transplantation: retrospective single-center study on 371 recipients

BACKGROUND

The increased risk of skin cancer is well known in heart and kidney transplant recipients, but fewer data exist on liver-transplant recipients (LTRs). The aim of this study was to analyze the prevalence, clinical features and risk factors of skin cancers in LTR treated mainly with tacrolimus.

METHODS

We selected LTR grafted in our hospital between January 1996 and December 2008, aged 20 years or more at the time of the study. Data were collected from the patients' medical files and with a questionnaire.

RESULTS

Three hundred seventy-one LTR were included. The median follow-up period was 8.2 years. The overall prevalence of skin cancers was 13.5%. The prevalence of melanoma was 1.3%. The squamous cell carcinoma to basal cell carcinoma ratio was 1:3. Both the overall cumulative patient risk of de novo skin malignancies and the squamous cell carcinoma-to-basal cell carcinoma ratio increased with time postgraft. The duration of immunosuppression was a risk factor, in addition to those common in the general population. No association was found between the primary liver disease and the development of skin cancer.

CONCLUSION

Contrasting with previous data of the literature, our findings suggest that, for a similar follow-up time, the risk of skin cancer in LTR is comparable to that of kidney transplant recipients.

Malignancies after pediatric kidney transplantation: more than PTLD?

Post-transplant lymphoproliferative disease (PTLD) is the most frequent malignant complication of transplantation in childhood. Even with modern post-transplant immunosuppressive strategies, 1-2% of all kidney transplant recipients will develop PTLD within the first 5 years after transplantation, and the risk remains high even thereafter as long as immunosuppression is required. In addition to PTLD, adult kidney transplant recipients have an increased incidence of other immunosuppression-related malignancies, such as non-melanoma skin cancer or Kaposi's sarcoma. It is foreseeable that pediatric transplant recipients will face similar complications during their adult life. Not only immunosuppression but also other risk factors have been identified for some of these malignancies. Strategies addressing these risk factors during childhood may contribute to life-long cancer prevention. Furthermore, early recognition and regular screening may facilitate early diagnosis and treatment, thereby reducing transplant-related morbidity. In this review we focus on malignant complications after renal transplantation and discuss known risk factors. We also review current screening strategies for malignancies during post-transplant follow-up.

A systematic review of conversion from calcineurin inhibitor to mammalian target of rapamycin inhibitors for maintenance immunosuppression in kidney transplant recipients

This was a systematic review of randomized controlled trials comparing delayed conversion of mammalian target of rapamycin inhibitors (mTORi) for calcineurin inhibitors (CNIs) versus CNI continuation in kidney transplantation. Databases (2000-2012) and conference abstracts (2009-2012) were searched giving a total of 29 trials. Outcomes analyzed included GFR, graft loss, rejection and adverse events and were expressed as weighted mean differences (WMDs) or as risk ratios (RRs). Patients converted to mTORi up to 1 year posttransplant in intention-to-treat analysis had higher GFR compared with those remaining on CNI (WMD 0.28 mL/min/1.73 m(2) , 95% confidence interval [CI] 0.21-0.36; I(2)  = 68%, p < 0.001). Stratifying trials by time posttransplant or type of mTORi did not change the overall heterogeneity. For on-treatment population, mTORi was associated with higher GFR (14.21 mL/min/1.73 m(2) , 10.34-18.08; I(2)  = 0%, p = 0.970) 2-5 years posttransplant. The risk of rejection at 1 year was higher in mTORi trials (RR 1.72, 1.34-2.22; I(2)  = 12%, p = 0.330). Discontinuation secondary to adverse events was more common in patients on mTORi, whereas the incidence of skin cancers and cytomegalovirus infection was lower in patients on mTORi. Conversion from CNI to mTORi is associated with short-term improvements in GFR in a number of studies but longer-term follow-up data of graft and patient survival are required.

CNI withdrawal for post-transplant lymphoproliferative disorders in kidney transplant is an independent risk factor for graft failure and mortality

Post-transplantation lymphoproliferative disorders (PTLD) are associated with poor patient and graft survival. The risk of rejection and subsequent graft loss are increased by the reduction of immunosuppression therapy, the cornerstone of PTLD treatment. This multicentre, retrospective, nonrandomized cohort study includes 104 adults who developed PTLD after renal or simultaneous renal/pancreatic transplantation between 1990 and 2007. It examines the effect of calcineurin inhibitor (CNI) withdrawal on long-term graft and patient survival. At 10 years postonset of PTLD, the Kaplan-Meier graft loss rate was 43.9% and graft loss or death with functioning graft was 64.4%. Cox multivariate analysis determined risk factors of graft loss as PTLD stage greater than I-II and CNI withdrawal, and for graft loss and mortality, these remained risk factors along with age over 60 years. Type and location of PTLD, year of diagnosis, and chemotherapy regime were not independent risk factors. Multivariate analysis determined CNI withdrawal as the most important risk factor for graft loss (HR = 3.07, CI 95%: 1.04-9.09; P = 0.04) and death (HR: 4.00, CI 95%: 1.77-9.04; P < 0.001). While long-term stable renal function after definitive CNI withdrawal for PTLD has been reported, this review determined that withdrawal is associated with reduced graft and patient survival.

Optimal management of skin cancer in immunosuppressed patients

Skin cancer is the most common malignancy in humans with basal cell carcinoma representing the majority of cases in the general population. The prevalence of skin cancer is increased amongst immunosuppressed patients such as those with lymphoproliferative disorders including non-Hodgkin lymphoma and chronic lymphocytic leukemia or those with iatrogenic immunosuppression following organ transplantation. In addition, these patients experience greater morbidity and mortality associated with skin cancers. The most common skin cancer in immunosuppressed patients is squamous cell carcinoma, which often presents with more aggressive features and has a greater rate of metastasis. This article reviews the risk factors, etiology, clinical presentation, and prevalence of skin cancer amongst immunosuppressed patients, including organ transplant, lymphoproliferative disorders, autoimmune disorders, and human immunodeficiency virus. We also provide a comprehensive review of treatment guidelines for immunosuppressed patients with cutaneous malignancy. Surgical therapy is the cornerstone of treatment; however, we also discuss pharmacologic treatment options, lifestyle modifications, and revision of immunosuppressive regimens.

The role of new immunosuppressive drugs in nonmelanoma skin cancer in renal transplant recipients

INTRODUCTION

Nonmelanoma skin cancer (NMSC) is the most common malignancy in patients who have received a solid organ transplant. Multiple factors are involved in the onset of posttransplant NMSC.

OBJECTIVES

To analyze the relationship between new immunosuppressive drugs and the onset of NMSC in renal transplant recipients.

METHOD

This was a combined retrospective and prospective observational study in which we studied 289 patients who received a kidney transplant between January 1996 and December 2010 at Hospital Universitario Doctor Peset in Valencia, Spain.

RESULTS

Seventy-three patients (25.2%) developed 162 NMSCs over a median follow-up of 72 months. There were no statistically significant differences in the onset of NMSC on comparing different induction therapy strategies involving monoclonal and polyclonal antibodies. NMSCs occurred less frequently in patients treated with mammalian target of rapamycin (mTOR) inhibitors than in those treated with other immunosuppressive regimens, although the differences were not statistically significant. Three of 5 patients with recurrent NMSC who were switched from calcineurin inhibitors to mTOR inhibitors developed additional NMSCs despite the change.

CONCLUSIONS

Induction therapy with monoclonal and polyclonal antibodies in renal transplant recipients is not associated with an increased risk of NMSC. While mTOR inhibitors are associated with a lower risk of posttransplant NMSC, it remains to be determined whether a switch to these drugs is useful in the management of patients who develop multiple NMSCs.

Merkel cell carcinoma in immunosuppressed patients

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous malignancy. The infectivity of Merkel cell polyomavirus (MCPyV), an apparent agent in MCC development, may be exacerbated with impaired immune responses. This paper reviews relevant data regarding the role of immunosuppression in the development of MCC and describes modes of immunodeficient states. Because of the inherently low incidence rate of MCC, several case studies and series are also briefly mentioned to provide a more comprehensive summary of MCC in the setting of immunosuppression. We describe immunosuppressed patients who have experienced excessive UV radiation, organ transplantation, human immunodeficiency virus infection/AIDS, autoimmune diseases, and lymphoproliferative disorders. Iatrogenic forms of immunosuppression are also highlighted. Studies that quantify risks consistently report that individuals with a history of solid organ transplantation, autoimmune diseases, AIDS, and/or lymphoproliferative diseases have a significantly elevated risk of developing MCC. Overall, immunocompromised patients also appear to have an early onset and more aggressive course of MCC, with poorer outcomes. Recommendations for multidisciplinary approaches are proposed to effectively prevent and manage MCC in these patients.

Sebaceous carcinoma of the suprapubic area in a liver transplant recipient

Sebaceous carcinoma is a very rare and potentially aggressive carcinoma originating from the epithelial lining of the sebaceous gland. More than 70% of all cases are in the head and neck region, especially the periorbita; therefore, they are classified into ocular and extraocular sebaceous carcinoma. The reported risk factors are advanced age, male sex, previous irradiation, and genetic predisposition for Muir-Torre syndrome. The current case is of sebaceous carcinoma found in the suprapubic area of a 67-year-old male patient who had received liver transplantation 6 years before, and had been receiving oral tacrolimus. Examination of the gastrointestinal system did not reveal any other malignancies. Although nonmelanoma skin cancers may occur as a complication after liver transplantation, there have been no previous reports of sebaceous carcinoma after liver transplantation. Furthermore, the sebaceous carcinoma in this case occurred in an uncommon location. We report this case along with a review of the literature.

Beyond calcineurin inhibitors: emerging agents in kidney transplantation

PURPOSE OF REVIEW

Despite their effectiveness, calcineurin inhibitors (CNIs) represent a major obstacle in the improvement of long-term graft survival in transplantation. The identification of new agents to implement CNI-free regimens is the focus of current transplant research. The purpose of this review is to summarize the novel immunosuppressive agents, including details about their mechanisms of action, stages of development, potential benefits and challenges.

RECENT FINDINGS

Targeting costimulation with belatacept is now an option for controlling the alloimmune response and has proved to be more effective in preserving long-term allograft function than CNIs despite an increased rate of acute rejection in some studies. mTOR inhibitors are also promising with their remarkable antineoplastic properties, though frequent side-effects may limit their broader use. Other agents under development include JAK inhibitors, CD40 blockade and leukocyte adhesion blockers, with unique potential benefits and side-effects in transplantation.

SUMMARY

Novel immunosuppressive agents are now available for use in CNI-free regimens in solid organ transplantation. Timing of initiation as well as long-term efficacy and safety are questions that remain to be answered in future clinical trials.

[Contraindications to lung transplantation: evolving limits?]

In France, the higher frequency of pulmonary sample in organ donors and the enhancement of surgical and perioperative life support techniques, have increased the number procedures and the short term prognosis of lung transplantation (LT). In this setting, the classical contraindications of LT need to be reconsidered. In this article, some of the classical contraindication of LT are confronted to the experience acquired in other solid organ transplantations or from some LT centers. Specific situations such as LT in patients with previous cancer, HIV infection, viral hepatitis, nutritional disorders, acutely ill LT candidates and aging candidates are addressed. Surgical contraindications are not reviewed.

Non-melanoma skin cancer is reduced after switch of immunosuppression to mTOR-inhibitors in organ transplant recipients

BACKGROUND

Organ transplant recipients are prone to the development of non-melanoma skin cancer. Organ transplant recipients often develop multiple non-melanoma skin cancers and the tumors show an aggressive growth pattern, therefore surgical therapy can be difficult. Switch of the immunosuppressive regimen to mTOR-inhibitors such as everolimus or sirolimus can have an antitumor effect.

PATIENTS AND METHODS

In a monocentric retrospective study we evaluated organ transplant recipients who presented with non-melanoma skin cancer in the years 2008-2010. Experience with patients who were switched to an mTOR-inhibitor due to non-melanoma skin cancer are reported in detail, and recent clinical studies are reviewed.

RESULTS

60 organ transplant recipients with non-melanoma skin cancer were evaluated. Due to the development of multiple non-melanoma skin cancer within a few years, the immunosuppressive regimen was switched to everolimus in 7 patients and to sirolimus in 5 patients. Eight patients were evaluable for the effect of mTOR-inhibitors on the development of non-melanoma skin cancer; 4 patients had to discontinue the medication with mTOR-inhibitors early due to various side effects. In the year before the switch to mTOR-inhibitors, 8 patients developed 16 squamous cell carcinomas, 3 Basal cell carcinomas and 22 cases of Bowen's disease. All tumors were histologically confirmed. In the year after switch of immunosuppression, the rate of squamous cell carcinomas (n = 2) and Bowen's disease (n = 3), but not of basal cell carcinomas (n = 2) was significantly reduced. Moreover, 5 prospective randomized trials recently have demonstrated a reduced number of non-melanoma skin cancers in organ transplant recipients after switch of the immunosuppressive regimen to mTOR-inhibitors.

CONCLUSION

Switch of the immunosuppressive regimen to mTOR-inhibitors should be considered for organ transplant recipients suffering from multiple non-melanoma skin cancers.

Skin cancer in kidney transplant recipients

Morbidity and mortality due to skin cancer is excessively high in renal transplant recipients compared to the general population. This epidemiologic difference is mainly due to the severe immunosuppression that enhances ultraviolet-induced DNA damage and leads to reactivation of potential oncogenic viruses. The most common skin cancer in transplant recipients is squamous cell carcinoma followed by basal cell carcinoma, while in the general population this ratio is reversed. Melanoma and cutaneous lymphoma are relatively rare although they occur more frequently in transplant patients than in the general population. Notably some tumors, such as Kaposi's sarcoma, are seldom encountered in the general population while they are frequently observed in transplant recipients. Local recurrences and visceral spreading are not so uncommon and pose a major issue for quality of life and overall prognosis of these patients. Timely diagnosis is essential and may be challenging, since the accuracy of clinical diagnosis is modest; thus skin biopsy is an essential tool for appropriate management. In this review, we describe the most common types of skin cancer in renal transplant recipients, with a focus on pathogenic issues that account for the different epidemiology and clinical expression of these neoplasms in this population.

The cutting edge of skin cancer in transplant recipients: scientific retreat of international transplant Skin Cancer Collaborative and Skin Cancer in Organ Transplant Patients Europe

The International Transplant Skin Cancer Collaborative (ITSCC) is an organization of more than 300 physicians and scientists focused on the study of dermatologic changes following solid organ transplantation. Transplant patients have a 100-fold increased risk of developing skin cancer. In October 2012, ITSCC and its European counterpart Skin Cancer in Organ Transplant Patients Europe held a joint biennial retreat in Essex, MA to discuss novel findings in the pathogenesis and management of skin cancer in solid organ transplant recipients. This meeting report is a summary of the novel findings discussed.

The role of mammalian target of rapamycin inhibitors in the management of post-transplant malignancy

Post-transplant malignancies, which occur either de novo or as cancer recurrences, are due to chronic exposure to immunosuppressive agents and are often more aggressive than those that develop in the non-transplant setting. Mammalian target of rapamycin (mTOR) inhibitors have antitumor and immunosuppressive effects. The dual effects of this class of agents may provide adequate immunosuppression to prevent organ rejection while simultaneously reducing the risk of post-transplant malignancy. mTOR inhibitors have become established approved agents for treating renal cell carcinoma and other cancers and, as reviewed herein, accumulating experience among organ transplant recipients collectively points toward a potential to prevent the development of de novo malignancies of various types in the post-transplant period. To date, most research efforts surrounding mTOR inhibitors and cancer control in the transplant population have been in the area of skin cancer prevention, but there have also been interesting observations regarding regression of post-transplant Kaposi's sarcoma and post-transplantation lymphoproliferative disorder that warrant further study.

Skin cancer in organ transplant recipients: more than the immune system

Organ transplant recipients (OTRs) are at increased risk of developing nonmelanoma skin cancers. This has long been thought to be caused by immunosuppression and viral infection. However, skin cancer risk among individuals with AIDS or iatrogenic immunodeficiency does not approach the levels seen in OTRs, suggesting other factors play a critical role in oncogenesis. In clinical trials of OTRs, switching from calcineurin inhibitors to mammalian target of rapamycin inhibitors consistently led to a significant reduction in the risk of developing new skin cancers. New evidence suggests calcineurin inhibitors interfere with p53 signaling and nucleotide excision repair. These two pathways are associated with nonmelanoma skin cancer, and squamous cell carcinoma in particular. This finding may help explain the predominance of squamous cell carcinoma over basal cell carcinoma in this population. Mammalian target of rapamycin inhibitors do not appear to impact these pathways. Immunosuppression, viral infection, and impaired DNA repair and p53 signaling all interact in OTRs to create a phenotype of extreme risk for nonmelanoma skin cancer.

The cutting edge of skin cancer in transplant recipients: scientific retreat of international transplant Skin Cancer Collaborative and Skin Cancer in Organ Transplant Patients Europe

The International Transplant Skin Cancer Collaborative (ITSCC) is an organization of more than 300 physicians and scientists focused on the study of dermatologic changes following solid organ transplantation. Transplant patients have a 100-fold increased risk of developing skin cancer. In October 2012, ITSCC and its European counterpart Skin Cancer in Organ Transplant Patients Europe held a joint biennial retreat in Essex, MA to discuss novel findings in the pathogenesis and management of skin cancer in solid organ transplant recipients. This meeting report is a summary of the novel findings discussed.

Synergism between mTOR pathway and ultraviolet radiation in the pathogenesis of squamous cell carcinoma and its implication for solid-organ transplant recipients

Nonmelanoma skin cancers (NMSCs) are the most common malignancies in the United States in immunocompetent patients. Among the solid-organ transplant recipients, NMSCs represent a significant disease burden, and they tend to be multiple and more aggressive. While the precise mechanisms responsible for the higher risk of developing cutaneous squamous cell carcinomas (SCCs) have not been completely elucidated, ultraviolet (UV) light has been established to be critical in initiation and promotion of tumor development. More recently, significant emphasis has been placed on the role of the mammalian target of rapamycin (mTOR) pathway in SCC pathogenesis. Furthermore, some studies have demonstrated the ability of mTOR inhibitors to decrease the incidence of new SCCs in the immunosuppressed transplanted patient population. In this review, we will highlight and examine the most recent available data on the role of UV radiation and its interaction with mTOR pathway signaling in SCC pathogenesis.

Lifespan extension and cancer prevention in HER-2/neu transgenic mice treated with low intermittent doses of rapamycin

Target of Rapamycin (TOR) is involved in cellular and organismal aging. Rapamycin extends lifespan and delays cancer in mice. It is important to determine the minimum effective dose and frequency of its administration that still extends lifespan and prevents cancer. Previously we tested 1.5 mg/kg of rapamycin given subcutaneously 6 times per two weeks followed by a two-week break (1.5 × 6/bi-weekly schedule: total of 6 injections during a 4-week period). This intermittent treatment prolonged lifespan and delayed cancer in cancer-prone female FVB/N HER-2/neu mice. Here, the dose was decreased from 1.5 mg/kg to 0.45 mg/kg per injection. This treatment was started at the age of 2 months (group Rap-2), 4 months (Rap-4), and 5 months (Rap-5). Three control groups received the solvent from the same ages. Rapamycin significantly delayed cancer and decreased tumor burden in Rap-2 and Rap-5 groups, increased mean lifespan in Rap-4 and Rap-5 groups, and increased maximal lifespan in Rap-2 and Rap-5 groups. In Rap-4 group, mean lifespan extension was achieved without significant cancer prevention. The complex relationship between life-extension and cancer-prevention depends on both the direct effect of rapamycin on cancer cells and its anti-aging effect on the organism, which in turn prevents cancer indirectly. We conclude that total doses of rapamycin that are an order of magnitude lower than standard total doses can detectably extend life span in cancer-prone mice.

The oncogene ATF3 is potentiated by cyclosporine A and ultraviolet light A

Cutaneous squamous cell carcinoma (SCC) represents the most important cutaneous complication following organ transplantation. It develops mostly on sun-exposed areas. A recent study showed the role of activating transcription factor 3 (ATF3) in SCC development following treatment with calcineurin inhibitors. It has been reported that ATF3, which may act as an oncogene, is under negative calcineurin/nuclear factor of activated T cells (NFAT) control and is upregulated by calcineurin inhibitors. Still, these findings do not fully explain the preferential appearance of SCC on chronically sun-damaged skin. We analyzed the influence of UV radiation on ATF3 expression and its potential role in SCC development. We found that ATF3 is a specifically induced AP1 member in SCC of transplanted patients. Its expression was strongly potentiated by combination of cyclosporine A and UVA treatment. UVA induced ATF3 expression through reactive oxygen species-mediated nuclear factor erythroid 2-related factor 2 (NRF2) activation independently of calcineurin/NFAT inhibition. Activated NRF2 directly binds to ATF3 promoter, thus inducing its expression. These results demonstrate two mechanisms that independently induce and, when combined together, potentiate the expression of ATF3, which may then force SCC development. Taking into account the previously defined role of ATF3 in the SCC development, these findings may provide an explanation and a mechanism for the frequently observed burden on SCCs on sun-exposed areas of the skin in organ transplant recipients treated by calcineurin inhibitors.

[Lung transplantation]

Lung transplantation is a therapeutic option for patients with end-stage lung diseases. Selection of candidates requires careful consideration of the disease-specific indications and contraindications for transplantation. Advances have been made in candidate selection via the ability to prognosticate outcomes of various lung diseases and through the implementation of the lung allocation score (LAS) with specific consideration of the degree of urgency and good postoperative survival rate, after neglecting the waiting time. This system has resulted in decreased mortality on the waiting list for lung transplantation. The availability of donor organs can possibly be increased by implementation of ex vivo lung perfusion as an alternative to conventional organ preservation. Risk factors for poor outcomes post-lung transplantation have been identified and understanding of the physiological, cellular and molecular mechanisms responsible for lung and airway damage has been extensively expanded. Primary graft dysfunction, infectious diseases, acute rejection, antibody-mediated rejection, lymphocytic bronchiolitis, obliterative bronchiolitis, restrictive allograft syndrome, and chronic lung allograft dysfunction are well defined complications and continue to be common causes of morbidity and mortality. This article provides a comprehensive update on these topics for the non-transplantation clinician.

PI3K-AKT signaling is a downstream effector of retinoid prevention of murine basal cell carcinogenesis

Basal cell carcinoma (BCC) is the most common human cancer. We have demonstrated previously that topical application of the retinoid prodrug tazarotene profoundly inhibits murine BCC carcinogenesis via retinoic acid receptor γ-mediated regulation of tumor cell transcription. Because topical retinoids can cause adverse cutaneous effects and because tumors can develop resistance to retinoids, we have investigated mechanisms downstream of tazarotene's antitumor effect in this model. Specifically we have used (i) global expression profiling to identify and (ii) functional cell-based assays to validate the phosphoinositide 3-kinase (PI3K)/AKT/mTOR pathway as a downstream target pathway of tazarotene's action. Crucially, we have demonstrated that pharmacologic inhibition of this downstream pathway profoundly reduces murine BCC cell proliferation and tumorigenesis both in vitro and in vivo. These data identify PI3K/AKT/mTOR signaling as a highly attractive target for BCC chemoprevention and indicate more generally that this pathway may be, in some contexts, an important mediator of retinoid anticancer effects.

The immune phenotype may relate to cancer development in kidney transplant recipients

High regulatory T-cell (Treg) numbers predict recurrent cutaneous squamous cell carcinoma in kidney transplant recipients, and the Treg immune phenotype may identify kidney transplant recipients at risk of developing squamous cell carcinoma and/or solid-organ cancer. To investigate this, a total of 116 kidney transplant recipients, of whom 65 had current or past cancer, were immune-phenotyped and followed up prospectively for a median of 15 months. Higher Treg (CD3+CD4+FOXP3+CD25(Hi)CD127(Lo)) proportion and numbers significantly increased the odds of developing cancer (odds ratios (95% CI) 1.61 (1.17-2.20) and 1.03 (1.00-1.06), respectively) after adjusting for age, gender, and duration of immunosuppression. Class-switched memory B cells (CD19+CD27+IgD-) had a significant association to cancer, 1.04 (1.00-1.07). Receiver operator characteristic (ROC) curves for squamous cell carcinoma development within 100 days of immune phenotyping were significant for Tregs, memory B cells, and γδ T cells (AUC of 0.78, 0.68, and 0.65, respectively). After cancer resection, Treg, NK cell, and γδ T-cell numbers fell significantly. Immune-phenotype profiles associated with both squamous cell carcinoma and solid-organ cancer in kidney transplant recipients and depended on the presence of cancer tissue. Thus, immune profiling could be used to stratify kidney transplant recipients at risk of developing cancers to identify those who could qualify for prevention therapy.

[Phototherapy and carcinogenesis]

Phototherapy successfully uses the short-term effects of ultraviolet light against inflammation and proliferation. For its long-term effects, however, ultraviolet light was recently classified as a carcinogen. The wave spectrum employed in phototherapy has various carcinogenic effects in experimental systems, most notably DNA mutations in keratinocytes. Clinically, PUVA increases the risk for squamous cell carcinoma of the skin, especially after following 350 or more phototherapy sessions over a lifetime. Melanoma and genital skin cancer are not increased by PUVA alone. Previous UV damage, immunosuppression and other systemic treatments increase cutaneous carcinogenesis through PUVA. In contrast, broad-band UVB, narrow-band UVB and UVA1 have not yet been linked to cutaneous carcinogenesis, but will need careful follow-up in larger studies. Phototherapy remains a safe treatment modality, provided that the indication is well-founded, previous exposure and co-carcinogens are considered, and short and dose-intensive treatment protocols are favored, PUVA is chosen as second-line treatment that should not be used for more than a lifetime total of 250-300 phototherapy sessions.

A randomized, controlled trial of everolimus-based dual immunosuppression versus standard of care in de novo kidney transplant recipients

Kidney transplant recipients receiving calcineurin inhibitor-based immunosuppression incur increased long-term risks of cancer and kidney fibrosis. Switch to mammalian target of rapamycin (mTOR) inhibitors may reduce these risks. Steroid or Cyclosporin Removal After Transplant using Everolimus (SOCRATES), a 36-month, prospective, multinational, open-label, randomized controlled trial for de novo kidney transplant recipients, assessed whether everolimus switch could enable elimination of mycophenolate plus either steroids or CNI without compromising efficacy. Patients received cyclosporin, mycophenolate and steroids for the first 14 days then everolimus with mycophenolate and CNIwithdrawal (CNI-WD); everolimus with mycophenolate and steroid withdrawal (steroid-WD); or cyclosporin, mycophenolate and steroids (control). 126 patients were randomized. The steroid WD arm was terminated prematurely because of excess discontinuations. Mean eGFR at month 12 for CNI-WD versus control was 65.1 ml/min/1.73 m² vs. 67.1 ml/min/1.73 m² by ITT, which met predefined noninferiority criteria (P = 0.026). The CNI-WD group experienced a higher rate of BPAR(31% vs. control 13%, P = 0.048) and showed a trend towards higher composite treatment failure (BPAR, graft loss, death, loss to follow-up). The 12 month results from SOCRATES show noninferiority in eGFR, but a significant excess of acute rejection when everolimus was commenced at week 2 to enable a progressive withdrawal of mycophenolate and cyclosporin in kidney transplant recipients.

Oncologic issues and kidney transplantation: a review of frequency, mortality, and screening

Kidney transplant recipients are at increased risk for development of malignancy compared with the general population, and malignancies occur at an earlier age. This increased risk, as expressed by the standard incidence ratio (SIR), varies widely, but it is highest in malignancies triggered by oncogenic viruses. For other cancers, this increased risk is the direct consequence of immunosuppressants promoting tumor growth and lowering immune system tumor surveillance. In this review, we briefly discuss the common malignancies with increased risk after kidney transplantation, explore the pros and cons associated with screening, and summarize current prevention and treatment recommendations.

Malignancies: pre and post transplantation strategies

The overall incidence of cancer is increased 2-3 fold in solid organ transplant recipients compared to the general population. The increase in risk is not uniform for all malignancies, in all ages or in all regions of the world. Several cancers are greatly increased, many are increased 2-4 fold and others do not appear to be increased at all. The pattern of increase is similar to patients with acquired immunodeficiency syndrome and those cancers most increased are associated with viral infections. These observations support the concept that much of the increased risk is from immunosuppression. Nonetheless there are differences between specific organ groups that deserve further examination. Those with advanced organ failure are also at increased risk for certain malignancies, which suggest either organ damage per se may pre-dispose to cancers or there are exposures to carcinogens in common. The purpose of this review to examine cancer incidence and mortality in solid organ transplantation and the role of pre transplant screening and post-transplant surveillance to reduce the burden of disease and improve patient outcomes. This review will focus on cancers that are common, associated with significant case fatality rates and have potential screening strategies to reduce burden of disease.