Cancer after transplantation

Recent Advances of RNA m6A Modifications in Cancer Immunoediting and Immunotherapy

Cancer immunotherapy, which modulates immune responses against tumors using immune-checkpoint inhibitors or adoptive cell transfer, has emerged as a novel and promising therapy for tumors. However, only a minority of patients demonstrate durable responses, while the majority of patients are resistant to immunotherapy. The immune system can paradoxically constrain and promote tumor development and progression. This process is referred to as cancer immunoediting. The mechanisms of resistance to immunotherapy seem to be that cancer cells undergo immunoediting to evade recognition and elimination by the immune system. RNA modifications, specifically N6-methyladenosine (m6A) methylation, have emerged as a key regulator of various post-transcriptional gene regulatory processes, such as RNA export, splicing, stability, and degradation, which play unappreciated roles in various physiological and pathological processes, including immune system development and cancer pathogenesis. Therefore, a deeper understanding of the mechanisms by which RNA modifications impact the cancer immunoediting process can provide insight into the mechanisms of resistance to immunotherapies and the strategies that can be used to overcome such resistance. In this chapter, we briefly introduce the background of cancer immunoediting and immunotherapy. We also review and discuss the roles and mechanisms of RNA m6A modifications in fine-tuning the innate and adaptive immune responses, as well as in regulating tumor escape from immunosurveillance. Finally, we summarize the current strategies targeting m6A regulators for cancer immunotherapy.

Renal oncocytoma in a kidney transplant patient: the imaging features on contrast-enhanced ultrasonography (CEUS): a case report

Renal oncocytoma is an infrequently reported renal neoplasm, often asymptomatic, which usually behaves as a benign entity and is identified accidentally on radiological imaging. Transplant patients under long-term immunosuppressive drugs have a high prevalence of cancers, such as skin cancers, lymphoproliferative disorders, and renal carcinomas. We present a case report of an asymptomatic renal oncocytoma in a kidney transplant recipient presenting persistent hematuria. The features of computed tomography and contrast-enhanced ultrasound (CEUS) are presented. This was the first time we used CEUS in a transplant kidney recipient presenting a renal mass, allowing the real-time visualization of contrast-enhancement patterns during all vascular phases for the differential diagnosis of renal tumors. Although the pattern of intense vascularization could mislead to an early judgment as a malignant lesion, it could help to exclude other renal lesions without inducing nephrotoxicity.

The Immunology of Melanoma

The relatively high DNA mutational burden in melanoma allows for the creation of potentially "foreign," immune-stimulating neoantigens, and leads to its exceptional immunogenicity. Brisk tumor-infiltrating lymphocytes, a marker of immune editing, confer improved overall survival in melanoma, possibly due to reduced sentinel lymph node spread. Meanwhile, T-cell-stimulating drugs, so-called T-cell checkpoint inhibitors, which reverse peripheral tolerance-dependent tumor escape, have demonstrated unparalleled clinical success in metastatic melanoma. Markers to predict response to immunotherapy are currently imperfect, and the subject of intense research, which will guide the future of ancillary pathologic testing in this setting.

Loss of Anti-HER-3 CD4+ T-Helper Type 1 Immunity Occurs in Breast Tumorigenesis and is Negatively Associated with Outcomes

BACKGROUND

We previously demonstrated a progressive loss of the anti-human epidermal growth factor receptor 2 (HER2) CD4+ T-helper type 1 (Th1) response during HER2^pos breast tumorigenesis. This loss is associated with residual disease following neoadjuvant therapy and increased risk of recurrence. In this study, we assessed the fate of anti-HER3 Th1 immunity during breast tumorigenesis.

METHODS

Peripheral blood from 131 subjects, including healthy donors (HDs), patients with benign breast disease (BD), ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC), was collected. Interferon (IFN)-γ^pos immune responses to four HER3-derived major histocompatibility complex (MHC) class II promiscuous peptides were tested via enzyme-linked immunosorbent (ELISPOT) assays, and three immune response parameters were compared: anti-HER3 (i) responsivity, or proportion of subjects responding to at least one peptide; (ii) repertoire, or number of responding peptides; and (iii) cumulative response, or summed peptide response.

RESULTS

A significant decline in anti-HER3 Th1 response was observed going from HDs to IBC patients; patients with triple-negative breast cancer (TNBC) demonstrated the lowest responses. HDs had significantly higher Th1 responses versus estrogen receptor (ER)^pos IBC and TNBC patients across all three immune parameters; HER2^pos IBC patients displayed responses similar to HDs and BDs. Patients with recurrent breast cancer and residual disease following neoadjuvant therapy demonstrated significantly lower anti-HER3 Th1 immunity compared with patients without recurrence or with a pathologic complete response to neoadjuvant therapy.

CONCLUSIONS

Anti-HER3 CD4+ Th1 responses decline during breast tumorigenesis, particularly in TNBC. Attempts to immunologically restore depressed responses in vulnerable subgroups may help mitigate recurrence.

Emerging strategies for cancer immunoprevention

The crucial role of the immune system in the formation and progression of tumors has been widely accepted. On one hand, the surveillance role of the immune system plays an important role in endogenous tumor prevention, but on the other hand, in some special circumstances such as in chronic inflammation, the immune system can actually contribute to the formation and progression of tumors. In recent years, there has been an explosion of novel targeted immunotherapies for advanced cancers. In the present manuscript, we explore known and potential various types of cancer prevention strategies and focus on nonvaccine-based cancer preventive strategies targeting the immune system at the early stages of tumorigenesis.

Melanoma in patients with chronic lymphocytic leukemia and non-Hodgkin lymphoma

BACKGROUND

The relationship between melanoma and chronic lymphocytic leukemia (CLL) or non-Hodgkin lymphoma (NHL) has been minimally investigated.

OBJECTIVE

The objective of this study was to examine the incidence of melanoma in patients with a history of CLL or NHL, and their associated mortality.

METHODS

Cohorts of Kaiser Permanente Southern California members with a history of CLL and NHL were identified. Age-adjusted incidence density rates of melanoma among patients with CLL or NHL were compared with rates of melanoma among the general population of Kaiser Permanente Southern California patients. The mortality of patients with melanoma was examined using Cox proportional hazards modeling.

RESULTS

The age-adjusted incidence rate per 100,000 person-years for melanoma among patients with either CLL or NHL was 107 (95% confidence interval 84.4-129.6) versus 25.9 among the general population (95% confidence interval 84.4-129.6, P < .001). Patients with melanoma and a history of CLL or NHL had 2.46 greater odds of death compared with those without CLL or NHL (95% confidence interval 1.77-3.41).

LIMITATIONS

This study was retrospective in nature; the International Classification of Diseases, Ninth Revision codes used may contain diagnostic errors; and only overall survival was used in our analysis.

CONCLUSIONS

Patients with a history of CLL or NHL have a higher incidence of melanoma. Patients with CLL or NHL who are subsequently given the diagnosis of melanoma have a higher mortality than patients with melanoma without a preceding diagnosis of CLL.

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.

De novo malignancies in renal transplant recipients: experience at a single center with 1882 transplant patients over 39 yr

PURPOSE

Cancers complicating organ allografts are a major cause of morbidity and mortality after renal transplantation. Different registries have described an overall three to eightfold increase in cancer risk compared with the general population. This retrospective study investigated the incidence and outcome of de novo malignancies following kidney transplantation in a single German kidney transplantation center.

MATERIALS AND METHODS

Between 1966 and 2005, 1882 patients underwent kidney transplantation at the Erlangen-Nuremberg kidney transplantation center. The incidence and types of post-transplant malignancies were retrospectively analyzed according to the patients' records and the database of the local cancer registry.

RESULTS

We identified 257 malignancies in 231 patients, an overall incidence of 13.7%. The mean follow-up time was 9.9 yr (range, 0.4-25.5 yr). The observed incidence data corresponded to a 12.1-fold increase in the overall risk of developing a malignant nonskin tumor compared with the nontransplanted population. Urinary tract malignancies represented the most frequent malignancies among the nonskin tumors (32.1%), followed by gastrointestinal tract (30.7%) and gynecological (14%) cancers. When we considered the duration from renal transplantation to tumor detection and tumor-specific survival, there was no difference between patients treated with or without a cyclosporine A-based regimen.

CONCLUSIONS

In our study, the overall risk of developing a post-transplant nonskin malignancy was 12.1-fold higher compared with the age-matched general population. Development of solid organ malignancies is one of the most frequent causes of morbidity and mortality in renal transplant recipients; thus, close tumor screening in patients after kidney transplantations is warranted.

Melanoma in organ transplant recipients: incidence, outcomes and management considerations

The incidence of melanoma continues to increase year on year. With better surgical techniques and medical management, greater numbers of organ transplants are being performed annually with much longer graft survival. The authors review our current understanding of the incidence of melanoma amongst organ transplant recipients, outcomes compared to the immunocompetent population, and management strategies in this burgeoning group.

Sarcoma immunotherapy

Much of our knowledge regarding cancer immunotherapy has been derived from sarcoma models. However, translation of preclinical findings to bedside success has been limited in this disease, though several intriguing clinical studies hint at the potential efficacy of this treatment modality. The rarity and heterogeneity of tumors of mesenchymal origin continues to be a challenge from a therapeutic standpoint. Nonetheless, sarcomas remain attractive targets for immunotherapy, as they can be characterized by specific epitopes, either from their mesenchymal origins or specific alterations in gene products. To date, standard vaccine trials have proven disappointing, likely due to mechanisms by which tumors equilibrate with and ultimately escape immune surveillance. More sophisticated approaches will likely require multimodal techniques, both by enhancing immunity, but also geared towards overcoming innate mechanisms of immunosuppression that favor tumorigenesis.

Incidence and clinicopathologic behavior of uterine cervical carcinoma in renal transplant recipients

BACKGROUND

Renal allograft recipients are reported to have a higher incidence of malignancy than the general population. This single hospital-based study examined the incidence and clinicopathologic behavior of uterine cervical carcinoma in renal transplant recipients.

METHODS

Among 453 women receiving renal transplantation from January 1990 to December 2008, 5 patients were diagnosed with cervical carcinoma. Medical records of these 5 patients were retrospectively reviewed, and clinicopathologic data were collected and analyzed.

RESULTS

The incidence of cervical carcinoma in renal transplant recipients was 58.1 out of 100,000 per year, which is 3.5 times higher than in the general Korean population. The mean interval between the time of renal transplantation and the time of cervical carcinoma diagnosis was 80.7 months. After a median follow-up of 96.2 months, there was no recurrence of the disease or death. In 4 patients who were positive from human papillomavirus in situ hybridization (HPV ISH), high or probably high risk HPV DNA was detected in all. Punctate staining of HPV ISH was detected in 3 out of 4 patients.

CONCLUSIONS

Higher incidence of cervical carcinoma is expected in renal transplant recipients, so appropriate surveillance is needed to ensure early detection and treatment of cervical carcinoma.

Revisiting cancer immunoediting by understanding cancer immune complexity

Since 1909, the cancer immunosurveillance concept has undergone four distinct eras. These include a general acceptance during 1957–1974, an abandonment during 1974–1996, resurrection during 1996–2001 in the form of an elegant theory of tumour immunoediting proposed by Robert Schreiber, and a retreat since 2006. Recently, in the Journal of Pathology, Ciampricotti et al reported an elegant experimental model designed by establishing RAG2−/−/MMTV-NeuT mice. Using this, they demonstrated that the development and metastasis of HER-2/neu-positive spontaneous mammary carcinoma were not altered by the presence or absence of the adaptive immune system. Their fascinating results are a call to revisit controversial reports as to an effective role of the adaptive immune system in tumour inhibition versus tumour promotion or tolerance in the development of spontaneous carcinomas. Ciampricotti and colleagues present a strong case for revising our ideas of cancer immunoediting and appreciating the complexity of the interaction between cancer and the immune system.

Role of apoptosis resistance in immune evasion and metastasis of colorectal cancer

The host immune system functions as a guardian against tumor development. It has been demonstrated that cytotoxic T lymphocyte (CTL)-mediated cytotoxic pathways function to inhibit or delay human colorectal cancer development. However, the host anti-tumor immune responses also 'edit' the tumor and select for more aggressive variants, resulting in immune evasion and tumor escape. Fas is a death receptor that mediates one of the major cytotoxic effector mechanisms of the CTLs. Fas is highly expressed in normal human colon epithelial cells but is frequently silenced in colorectal carcinoma, especially in metastatic colorectal carcinoma, suggesting that loss of Fas expression and function may be an immune evasion and tumor escape mechanism. In addition, recent studies indicated that Fas also mediates cellular proliferation signaling pathways to promote tumor development. Therefore, the death receptor Fas may not only transduce death signals to suppress tumor development but also activate cellular proliferation and the migration process to promote tumor growth and progression. Thus, understanding the mechanisms by which the Fas receptor and its associated protein complex transduces the death and survival signals may identify molecular targets for the development of therapeutic strategy to enhance the Fas-mediated death signals to increase the efficacy of cancer immunotherapy.

Carcinogenicity assessments of biotechnology-derived pharmaceuticals: a review of approved molecules and best practice recommendations

An important safety consideration for developing new therapeutics is assessing the potential that the therapy will increase the risk of cancer. For biotherapeutics, traditional two-year rodent bioassays are often not scientifically applicable or feasible. This paper is a collaborative effort of industry toxicologists to review past and current practice regarding carcinogenicity assessments of biotherapeutics and to provide recommendations. Publicly available information on eighty marketed protein biotherapeutics was reviewed. In this review, no assessments related to carcinogenicity or tumor growth promotion were identified for fifty-one of the eighty molecules. For the twenty-nine biotherapeutics in which assessments related to carcinogenicity were identified, various experimental approaches were employed. This review also discusses several key principles to aid in the assessment of carcinogenic potential, including (1) careful consideration of mechanism of action to identify theoretical risks, (2) careful investigation of existing data for indications of proliferative or immunosuppressive potential, and (3) characterization of any proliferative or immunosuppressive signals detected. Traditional two-year carcinogenicity assays should not be considered as the default method for assessing the carcinogenicity potential of biotherapeutics. If experimentation is considered warranted, it should be hypothesis driven and may include a variety of experimental models. Ultimately, it is important that preclinical data provide useful guidance in product labeling.

[Malignant neoplasms and kidney transplantation]

Together with cardiovascular disorders and metabolic changes, malignant diseases are considered as great challenges in clinical transplantation. As far as long-term function of transplanted organs is concerned, an impact of malignancies is obvious. However, it is important to distinguish between neoplastic disease originating from preexisting lesions in the transplanted organs and de novo graft tumors. Further, there is also a high risk of developing malignant disease during the dialysis, likely due to potential harmful metabolic changes associated with this procedure. After curative management of tumors in such patients, an interval of 2 years for surveillance should be adhered to before patients are put back on the waiting list. The overall risk of transmission of a malignant disease with the transplanted graft has been considered to be as low as <0.2%. In this context, and considering the continual shortage of donated organs, there is an international consensus about the use of kidney grafts with a history of small tumors (<2 cm in diameter und low-grade, i.e., G1). However, the lesions should have been removed with subsequent histopathologic characterization before the acceptance of the organ for transplantation. Early diagnosis and management of de novo malignant disease in transplant patients is crucial for the prognosis of graft function and patient survival. Genitourinary malignancies are frequent among de novo malignancies in transplanted patients. Thus, there is a need for clearly structured concepts for screening of transplant patients in order to detect early malignancies. The incidence of malignant disease correlates directly with the extent of immunosuppression in patients with end-stage renal disease (ESRD) on dialysis, as well as after transplantation with life-long immunosuppressant therapy. In addition, also geographic factors seem to play a role in the differential incidence of tumors among different populations. For instance, the highest incidence of malignancies among immunosuppressed patients has been observed in Australia followed by the USA and Europe. This might be due to the high incidence of de novo skin cancer, which has been linked to the extent of UV exposure.

Regression of advanced melanoma upon withdrawal of immunosuppression: case series and literature review

We report two cases of stage IV malignant melanoma arising in patients treated with azathioprine for myasthenia gravis. In both cases, the melanoma metastases regressed upon withdrawal of immunosuppression. One patient remains melanoma free at 10 years, and the second patient experienced an 18-month disease free period. There is one prior case report in the medical literature to support full immune reconstitution for treatment in advanced immunosuppression-related melanoma, and one case series suggesting that transplant patients developing melanoma may benefit from a switch to sirolimus. Virtually, no data exist for the medical management of early stage melanoma in the immunosuppressed patients. We review the limited preclinical data in support of immune reconstitution and the data on immunosuppression as a risk factor for melanoma. We conclude that reduction or withdrawal of immunosuppression may be beneficial in patients with advanced stage melanoma and warrants further consideration in patients with early stage melanoma.

Immune manipulation of advanced breast cancer: an interpretative model of the relationship between immune system and tumor cell biology

This review summarizes some recent clinical immunological approaches with cytokines and/or antibodies for therapy of advanced breast cancer. It considers the recent advances in genetics and molecular tumor biology related to impaired immunosurveillance involving cytokines and growth factors to explain clinical results. Evasion of the host immune attack might be induced by the following groups of mechanisms: (a) tumor dependent (genomic instability, HLA class I antigen abnormalities, upregulation of fetal type nonclassical HLA class I molecules, epitope immunodominance, apoptosis inhibition by defective death receptor signaling, apoptosis of activated T cells, tumor cannibalism and constitutive activation of signal transducer, and activator of transcription-3 (Stat 3) and nuclear factor-kappaB (NF-kappaB) signaling); (b) host dependent (CD4+CD25+ regulatory T cells (T reg), CD4+ T cells anergy, Th2 antitumor immunity diversion and myeloid suppressor cells); (c) tumor and host dependent (lack of co-stimulation molecules, immunosuppressive cytokines (vascular endothelial growth factor (VEGF), interleukin (IL)-10, prostaglandin (PG)E2, transforming growth factor (TGF)-beta)). Cytokines and growth factors are involved in virtually all three types of mechanisms. These mechanisms are integrated with the current knowledge of tumor growth and inhibited apoptosis primarily mediated by cytokines and growth factors to propose an interpretation of the relationships among tumor cells, tumor stroma, and tumor-infiltrating lymphocytes. Tumor growth, defective immunorecognition and immunosuppression are the three principal effects considered responsible for immune evasion.

Incidence and clinical behavior of papillary thyroid carcinoma in renal allograft recipients: a single center experience

The chronic use of immunosuppressive therapy in transplant recipients increases the long-term risk for carcinoma. However, there is insufficient knowledge regarding the incidence and biological behavior of papillary thyroid carcinomas (PTC) in renal allograft recipients. In the present study we examined the incidence and biological behavior of PTCs among 1739 patients transplanted between January 1986 and December 1999 who had been followed for a mean period of 137 months (range, 84-238 months). During the follow-up, 129 (7.4%) recipients were identified to display posttransplantation malignancies, including 12 (0.7%) with PTCs. The 6 male and 6 female patients had a mean age of 41 years (range, 23-57 years). Nine cases (incidentalomas) were diagnosed based on ultrasonographic (US) screening. Eight of those 9 were TNM stage I, 2 of the 3 clinical carcinomas were TNM stage IVa. During a mean follow-up of 94 months (range, 18-159 months), 2 (16.7%) PTC patients developed locoregional recurrence, but no patients showed distant metastases. These data showed that recipients had a higher incidence of PTC compared with the general Korean population (0.7% vs 0.02%). Posttransplantation PTC tended to show no difference in gender distribution, and was often associated with aggressive lymphatic metastasis. However, most incidentalomas showed favorable treatment outcomes. In conclusion, routine surveillance of the thyroid gland using US screening is recommended to ensure early detection, treatment, and favorable prognosis of PTC.

The utility of bone marrow examination in renal transplantation: nine years of experience from north India

Renal transplantation may be complicated by persistent fever and cytopenia. Bone marrow examination, though painful and invasive, may be of value because it can be performed in most peripheral hospitals, and the results are rapidly available. In a retrospective analysis, clinical records, marrow aspirates, and trephine biopsies were assessed to determine the indications for bone marrow examination and the findings in 132 patients over a 9-year period. In 7 of 61 (11%) patients with fever, a specific infection or a malignancy was identified, and hypocellularity was seen in 85% of cases. Nutritional deficiency with megaloblastosis or diminished iron stores was noted in 29% of cases. Malignancies were relatively infrequent (3%). Overall, in 12% of the cases, bone marrow examination provided useful information. Examination of the bone marrow may be a useful diagnostic test in pyrexia of unknown origin and cytopenia, particularly in developing countries.

Liver resection for hepatocellular carcinoma in patients who have undergone prior renal transplantation

BACKGROUND AND OBJECTIVES

Because renal transplantation recipients require immunosuppressive drugs, they have a higher incidence of subsequent malignancies. Among them, hepatocellular carcinoma (HCC) is common. Although liver resection remains an option for curing HCC, the role of liver resection in renal transplantation recipients remains unclear.

METHODS

A retrospective review of liver resection for newly diagnosed HCC in 680 patients was conducted. Among them, 18 patients had undergone prior renal transplantation (RT group). The patient background, tumor characteristics, early and long-term results after liver resection were compared with the other 662 patients who had not previously undergone renal transplantation (non-RT group).

RESULTS

The patient's background characteristics were comparable between RT and non-RT group. The tumor characteristics, postoperative morbidity, and mortality were not significantly different between the two groups. The 5-year disease-free survival rates in RT and non-RT groups were 18.8% and 41.2%, respectively (P = 0.242), whereas 5-year actuarial survival rates in RT and non-RT groups were 59.1% and 58.3%, respectively (P = 0.738). Two patients lost their graft kidney 3 and 8 years after liver resection.

CONCLUSION

With careful protection of the graft kidney, liver resection is still a justified treatment option for HCC in patients who have undergone renal transplantation.

Melanomas in renal transplant recipients

BACKGROUND

It is well documented that renal transplant recipients are at increased risk of developing skin cancers, in particular squamous cell carcinomas. Less extensively reviewed in the literature is the increased incidence of malignant melanoma. We have reviewed 10 patients in the Oxford renal transplant population who developed 12 melanomas following transplantation.

OBJECTIVES

To determine the incidence and characteristics of melanoma in renal transplant recipients.

METHODS

We reviewed the case notes and pathology of all patients who developed melanoma within the Oxford Renal Transplant Unit. The clinical details were recorded including date of transplant, immunosuppressive therapy, interval between transplant and melanoma, site of occurrence, history of sun exposure, type of clinician diagnosing the melanoma, history of other skin malignancies and outcome. From the histopathology we documented various prognostic factors.

RESULTS

Ten patients developed 12 melanomas (one patient had three melanomas) from a population of 1874 transplanted patients. The total number of transplant years was 11 942.2. The incidence of melanoma in our population was 12 per 11 942.2 transplant years, which is approximately 8 times greater than the standardized rate for this region. We found that the mean interval between transplant and melanoma was approximately 11 years (median 8.5). A dermatologist was the diagnosing clinician in at least 67% of cases. Melanomas occurred on the trunk in the majority of cases (58%), followed by the upper limb (25%). All patients apart from one are alive with no recurrence of their melanoma. One patient died as a result of metastatic melanoma. The mean follow-up period following melanoma was 3.7 years. In all patients apart from the patient who died, the melanomas were < 1 mm Breslow thickness. That patient's melanoma was 4.5 mm thick. There was no precursor naevus in eight of the 12 melanomas. In two there was a precursor dysplastic naevus. In the cases in vertical growth phase the tumour-infiltrating lymphocyte response was absent in four cases and nonbrisk in one patient.

CONCLUSIONS

In the Oxford transplant population studied melanomas occurred at approximately 8 times the rate in the general population. This is the highest rate reported in the literature. The patients had a better outcome than reported previously. This may be due to detection at a relatively early stage. Renal transplant recipients attend dedicated dermatology clinics in Oxford, which may have contributed to the early diagnosis and good outcome.

Skin cancer and immunosuppression

All immunosuppressive treatments, either pharmacological or physical, have the potential to impair the skin immune system network of cells and cytokines, thus leading to an increased incidence of skin cancer. Since skin cancer in transplant recipients may show uncommon clinical features and have an unusually aggressive course, transplant patients should be strictly followed up by experienced dermatologists in order to diagnose and treat properly any skin cancer in an early phase. Importantly, due to the fact that sun exposure increases immunosuppression in the skin, patients should be clearly informed about the additional risk of sun exposure and the preventive measures to be taken.

Later Evolution After Cardiac Transplantation in Chagas’ Disease

OBJECTIVE

This research reported the accumulated experience with cardiac transplantation in Chagas' disease, emphasizing reactivation, immunosuppression, and mortality.

METHODS

Fifty-nine patients undergoing cardiac transplantation had Chagas' disease with classically accepted recipient selection criteria. In this series, 84.7% of the patients were functional class IV; 36.0% used vasopressor support; and 13.5% mechanical circulatory assistance. One patient received a heart and kidney transplantation.

RESULTS

After the initial experience the doses of immunosuppressants were significantly reduced with improvement in outcomes. The diagnosis of the reactivation of disease was documented by the identification of parasite in the myocardium, or on subcutaneous or serological exams. Reactivation of disease was significantly reduced by decreasing the immunosuppression. Immediate mortality occurred in 10 cases: three infections, two allograft dysfunction, two rejections, and two sudden deaths. Subsequent mortality happened in 14 patients: four by lymphoma, three by infection, two by Kaposi's sarcoma two by rejection, two by constrictive pericarditis, and one by reactivation of disease in the brain.

CONCLUSIONS

There's no correlation between the disease and pre- or postoperative prophylaxis. The early diagnosis and specific treatment of reactivation did not leave functional sequelae in the myocardium. Reduction in immunosuppression significantly reduced reactivation of disease and neoplasms. The combined transplantation can be realized safely with more care about the immunosuppressants.

De novo cancer occurrence after renal transplantation: a medical center experience in Taiwan

INTRODUCTION

Renal transplantation has been advocated as the treatment of choice for end-stage renal disease. Organ transplantation increases the incidence of cancer through unclear mechanisms. A literature review showed that the most common neoplasms are of skin origin, which are uncommon in Eastern people. We reviewed cancer patterns in our renal transplant series.

MATERIALS AND METHODS

From July 1981 to December 2002, among 560 renal transplantations performed in this hospital, we retrospectively surveyed cancer incidence, types, and usage of immunosuppressants.

RESULTS

Twenty nine cancer cases 5.18% (incidence) included hepatocellular carcinoma (HCC) as the highest mortality rate (9 of 13 cases). Eight of these 13 cases were hepatitis B carriers. All four hepatitis C carriers expired three of them with unresectable multinodular tumors at diagnosis in Posttransplantation lymphoproliferative disorder (PTLD) was the second most common cancer (seven cases); all but one survived with reduced doses of or changes in immunosuppressants. No skin cancer other than four Kaposi's sarcomas with skin manifestations was detected in our series.

DISCUSSIONS

HCC was the main cancer in our series. Accepting hepatitis B carriers as candidates for renal recipients and donors may be one of the causes. PTLD was the second most common cancer, while there were no skin cancers.

THYROID CANCER IN THE RENAL TRANSPLANT POPULATION: EPIDEMIOLOGICAL STUDY

BACKGROUND

The epidemiology of thyroid neoplasms in the renal transplant population has not been widely published. The present study compares the behaviour of thyroid cancer in the transplant cohort with that of the general population. It also documents the transplantation outcomes of patients with thyroid and non-thyroid cancers.

METHODS

All recipients of renal grafts are registered with the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Data were obtained from this institution and analysed using Microsoft Excel and Stata statistical software. Risk ratio, attributable risk, Mann-Whitney test, and the Kaplan-Meier survival probability were calculated.

RESULTS

Between 1963 and 31 March 2002, 23 (0.22%) patients were diagnosed with thyroid cancer from a cohort of 10,689 renal transplant recipients. The median age in the renal-transplant thyroid cancer group was 48.2 years (range: 23-67 years), and there were 11 (48%) male patients, compared to 26% of thyroid cancer patients in the general population (P = 0.02). The median time to thyroid cancer diagnosis after transplantation was 68 months (range: 3-253 months) compared to 102 months (range: 3-363 months; P = 0.004) in non-thyroid cancers. Ten patients (43%) were found to have lymphatic metastasis, eight of whom presented at the time of primary diagnosis. The risk ratio (RR) was 5.2 (95% confidence interval: 2.0-16.6), with an attributable risk of 17.4 cases per 10,000. There were two cancer-related deaths resulting in a survival probability of 89% at 5, 10 and 15 years.

CONCLUSIONS

There is a higher incidence of thyroid cancer and an altered sex distribution in the renal transplant population. A significant proportion presents with lymphatic metastasis requiring lymph node dissection and radioactive iodine treatment.

The three Es of cancer immunoediting

After a century of controversy, the notion that the immune system regulates cancer development is experiencing a new resurgence. An overwhelming amount of data from animal models--together with compelling data from human patients--indicate that a functional cancer immunosurveillance process indeed exists that acts as an extrinsic tumor suppressor. However, it has also become clear that the immune system can facilitate tumor progression, at least in part, by sculpting the immunogenic phenotype of tumors as they develop. The recognition that immunity plays a dual role in the complex interactions between tumors and the host prompted a refinement of the cancer immunosurveillance hypothesis into one termed "cancer immunoediting." In this review, we summarize the history of the cancer immunosurveillance controversy and discuss its resolution and evolution into the three Es of cancer immunoediting--elimination, equilibrium, and escape.

De novo tumors after kidney transplantation: the Budapest experience

In a retrospective study we analyzed the incidence and characteristics of de novo tumors developing in renal transplant recipients treated in our center. The 5% incidence de novo tumors developing among patients treated with azathioprine and prednisolone (n = 241) was similar to the 5.4% incidence of de novo tumors developing among patients treated with calcineurin-based immunosuppression (n = 1918). The most common malignancies among our patients were basal cell (21.7%) and squamous cell (13.9%) carcinomas of the skin, followed by urogenital (10.4%) and lung malformations (9.6%). A high incidence of Kaposi's sarcoma (9.6%; half cutaneous and half visceral) and a lower than expected incidence of posttransplant lymphoproliferative disorder (PTLD; 3.5%) was found. Among patients developing de novo tumors, the incidence of death with a functioning graft was higher than among recipients without tumors. Moreover, the incidence of tumor-related death was high among the de novo tumor recipients. Among our recipients, the most aggressive tumors were Kaposi's sarcoma, lung tumors, lymphomas, and gastrointestinal tumors, which occurred relatively early after transplantation and were the cause of death in most cases. Compared to tumor registry data, we found an inverse basal-to-squamous cell carcinoma ratio, a lower incidence of PTLD, and a higher incidence of Kaposi's sarcoma.

Cancer immunoediting: from immunosurveillance to tumor escape

The concept that the immune system can recognize and destroy nascent transformed cells was originally embodied in the cancer immunosurveillance hypothesis of Burnet and Thomas. This hypothesis was abandoned shortly afterwards because of the absence of strong experimental evidence supporting the concept. New data, however, clearly show the existence of cancer immunosurveillance and also indicate that it may function as a component of a more general process of cancer immunoediting. This process is responsible for both eliminating tumors and sculpting the immunogenic phenotypes of tumors that eventually form in immunocompetent hosts. In this review, we will summarize the historical and experimental basis of cancer immunoediting and discuss its dual roles in promoting host protection against cancer and facilitating tumor escape from immune destruction.

Persistent Epstein-Barr virus infection: unrestricted latent and lytic viral gene expression in healthy immunosuppressed transplant recipients

BACKGROUND

Posttransplant lymphoproliferative disease (PTLD) is a common Epstein-Barr virus (EBV)-associated complication of transplantation which, despite treatment, is often fatal. This study was undertaken to monitor persistent EBV infection in transplant recipients, to compare EBV load and gene expression in healthy individuals and EBV-associated diseases, and to highlight differences in PTLD that could be used to define those at risk of the disease.

METHODS

A cohort of 96 cardiothoracic transplant recipients was monitored posttransplant for up to 1110 days (median 268 days). Levels of EBV DNA and viral mRNA transcripts in peripheral blood mononuclear cells (PBMs) were measured at regular intervals and compared with those found in healthy individuals, infectious mononucleosis (IM) patients, and 12 PTLD patients bled at the time of diagnosis. Overall posttransplant levels were significantly higher than pretransplant and healthy subjects, and correlate with dose of immunosuppression. EBV DNA levels in both IM and PTLD were significantly higher than in healthy recipients, with the highest levels in PTLD patients. Individual measurements in 12 healthy transplant recipients reached levels seen in PTLD, and thus single estimations are not of predictive significance for PTLD development.

RESULTS

Analysis of viral gene expression in peripheral blood mononuclear cells showed a restricted (LMP 2 only) pattern in healthy subjects, and an unrestricted (latency 3) pattern with lytic replication in 14% of IM blood and 45% of cases of PTLD. A total of 55% of healthy transplant recipients had additional transcripts in one or more blood samples, and this finding correlated with high viral load. Analysis of the 12 samples from healthy recipients with viral loads equivalent to those seen in PTLD showed additional transcripts in all cases and latency 3 with lytic replication in 33%. Thus, an isolated finding of high viral load and/or unrestricted latent and lytic gene expression is not indicative of PTLD.

Continent urinary diversion in preparation for renal transplantation: a staged approach

BACKGROUND

We prospectively assessed the safety of kidney transplantation into continent urinary intestinal reservoirs as a planned two-stage procedure in patients with absent or dysfunctional lower urinary tract.

METHODS

Between November 1990 and June 1999, 12 patients have undergone renal transplantation into continent urinary reservoirs, and a further patient with a diversion is awaiting transplantation. This was part of a larger series of 356 patients who had undergone continent diversions during that period. A further 174 patients (33%) had diversions into ileal conduits.

FINDINGS

Within a mean follow-up of 26.1 months (5-72) after transplantation renal function was stable with serum creatinine values ranging from 0.9 to 1.8 mg/dl. There were 5 reoperations in the 12 patients (40%). Two patients needed their continence mechanism replaced. One had renal vein thrombosis with loss of the transplant. The cause for this was unknown but it had been speculated that it could have been caused by graft/body size disproportion. A second kidney was successfully transplanted after 12 months. Two further revisions were required for ureteric kinking and lymphocele. The patient with orthotopic substitution voids to completion. The other patients are continent day and night with easy catheterization.

INTERPRETATION

This is one of the largest single series reported to date of renal transplantation into continent urinary diversions, and we commend the approach in carefully selected patients, but the difficulties must not be underestimated and the specific problems of intestinal urinary reservoirs have to be reckoned with. These procedures should be confined to centers with considerable experience with this type of surgery and its complications. Lifelong close surveillance is critical for the success of this concept.

Tumour induction as a consequence of immunosuppression after renal transplantation

Immunosuppressed recipients of organ transplants have a higher incidence of carcinoma than the general population. A retrospective analysis was made at the Department of Urology of Bonn University, investigating 236 renal allograft recipients as to the incidence of neoplasms before and after transplantation. Eleven patients developed malignant tumours after transplantation. In 4 out of these 11 patients, case history showed pre-existing malignancies. Two of the 4 patients developed a second tumour, while the other two had tumour progression (latency period 21-77 months). Three of the 4 patients died of their tumours 21, 42 and 77 months after transplantation, whereas one female patient is still alive and free of neoplasms 32 months after transplantation. In 7 out of these 11 patients de novo tumours were diagnosed (latency period 3-88 months). All of them are still alive (NED between 15 and 85 months), six of them with good transplant function. There was no difference to be seen in the incidence of malignancies between kidneys supplied by Eurotransplant (n = 40) and ABO compatible kidneys from our own donors (n = 196). The higher incidence rate of neoplasms in transplant recipients requires high standards in preventive measures. Any suspicious change that may occur in the course of a thorough follow-up of transplant recipients must be removed and examined histologically. Patients with previous malignant diseases must be payed special attention, since they frequently tend to develop another malignant tumour and progression of existing tumours, respectively. As far as immunosuppression is concerned, therapeutic guidelines for the treatment of transplant recipients do not differ from those set up for patients on haemodialysis. Since immunosuppression with increased rates of tumour incidence can also be observed in dialysis patients, the mere fact of increased incidence of neoplasms cannot be taken as an argument against transplantation. With a more or less equal risk of tumour incidence the crucial factor should be the higher quality of life for transplant recipients.

Malignant tumours after renal transplantation

In 1243 patients after renal transplantation, 39 malignant tumours were detected in 37 patients. The average latency period between transplantation and tumour disease was 72 months. Tumours included 8 malignant lymphomas, 7 dermatomas and 24 visceral tumours. The patients who developed a tumour had received fewer blood transfusions before transplantation than a tumour-free control group of 60 patients with renal transplants. Rejection crises occurred in a significantly smaller number of tumour patients compared with the control group.

Malignant melanoma in organ allograft recipients

Three groups of tumors were studied. The first group was melanomas inadvertently transmitted from donors. Brain metastases from melanoma were often misdiagnosed in the donors as primary brain tumors or cerebral hemorrhage. Eleven donors provided organs to 20 recipients of whom 3 never manifested evidence of melanoma, 1 showed local spread of tumor beyond the allograft, and 16 had metastases. Of the last group 11 died from melanoma, but 4 patients had complete remissions following transplant nephrectomy and discontinuation of immunosuppressive therapy. The second group was Melanomas treated pretransplantation. Thirty patients had cutaneous melanomas and one an ocular melanoma. Six patients (19%) had recurrences posttransplantation. Three were treated < 2 years pretransplantation, 2 between 2-5 years pretransplantation, and one 120 months pretransplantation. The third group was De novo melanomas. Cutaneous melanomas occurred in 164 patients, melanomas of unknown origin in 8, and ocular melanomas in 5. Melanomas constituted 5.2% of posttransplant skin cancers compared with 2.7% in the general population. Unusual features of cutaneous melanomas were that 6 (4%) occurred in children, and 9 (5%) occurred in bone marrow recipients who were treated for leukemia. Forty-four patients (27%) who had cutaneous melanomas also had other skin cancers. Forty-seven of 68 patients (69%) had thick skin lesions (Clark's level III or greater or > 0.76 mm by Breslow's technique). Lymph node metastases occurred in 32 patients (20%) with cutaneous melanomas. Fifty patients (30%) with cutaneous melanomas died of their malignancies, as did 5 with melanomas of unknown origin, and 1 with ocular melanoma. The risks of melanoma may be reduced by stringent selection of donors; by waiting at least 5 years between treatment of melanoma and undertaking transplantation; and, perhaps, by reducing sunlight exposure and by early excision of suspicious dysplastic lesions.

Malignancies of the genito-urinary system following renal transplantation

OBJECTIVE

To analyse the development of malignancies of the genito-urinary system after renal transplantation.

PATIENTS AND METHODS

A total of 868 renal graft recipients were followed up over a mean period of 41.8 +/- 45 months. Fifteen patients received grafts from living related donors and 853 were transplanted with kidneys from cadavers.

RESULTS

Twelve patients (1.4%) exhibited cancer of the genito-urinary system: 11 tumours were de novo malignancies. One small renal carcinoma was transplanted from a living related donor. The incidence of tumours of the genito-urinary system was 34 in 100,000 patient years in the patients treated with cyclosporin and 32 in 100,000 patient years in the conventional therapy group. Four patients died within a mean survival time of 14.4 months. Comparison of our results with sex- and age-specific incidence rates in a reference population showed an increase in malignant tumours of the genitourinary system by a factor of 7.3 in males and 11.2 in females.

CONCLUSIONS

The frequency of disorders after transplantation necessitates routine examinations in organ transplanted recipients both before and at regular intervals after transplantation, including the patient's native kidneys and cervical smears in females.

Epstein-Barr virus as an agent of haematological disease

Epstein-Barr virus (EBV) encodes genes that permit its persistence in human B lymphocytes and genes that ensure its replication in epithelial cells. Immune restraints on the virus are usually so effective that most EBV infections are limited to a minute fraction of B lymphocytes and of epithelial cells. As a result, most EBV infections are never symptomatic. Occasionally, the virus causes disease, often with the cooperation of the immune system or other less characterized cofactors. Infectious mononucleosis, a generally self-limited lymphoproliferative illness common in adolescents and young adults, is due to primary EBV infection and to the brisk cellular immune response it elicits. Lymphoproliferative disorders of EBV-infected B cells arise almost exclusively when cellular immunity is grossly compromised. EBV-positive Burkitt's lymphoma contain a translocated and deregulated c-myc oncogene and EBV-positive non-Hodgkin's lymphomas are characterized by the presence of Reed-Sternberg's and Hodgkin's cells, features that have not been directly linked to EBV. Many recent observations, however, including evidence that virus infection precedes malignant transformation and is often associated with a characteristic pattern of viral gene expression, provide continued interest in the relationship between the virus and these haematological malignancies.

Cancer risk after renal transplantation in the Nordic countries, 1964-1986

The theory that cancer may arise under conditions of reduced immune capacity is supported by observations of humans with immune deficiencies such as occur following organ transplants. However, no study on humans has been done in which the reference population was the same as that in which the cancer cases arose and in which there was a sufficiently long period of follow-up. Information on 5,692 Nordic recipients of renal transplants in 1964-1982 was linked with the national cancer registries (1964-1986) and population registries. Person-years at risk were calculated from the date of first transplantation until death or the end of the study period and were multiplied by the appropriate age- and calender-specific incidence rates to obtain the expected numbers of cancers. Standardized incidence ratios (SIR) were calculated after stratification by a number of recorded variables. Altogether, 32,392 person-years were accrued, and 471 cancers occurred, yielding overall SIR of 4.6 (95% CI, 4.0 to 5.2) for males and 4.5 (95% CI, 4.0 to 5.2) for females. Significant overall 2- to 5-fold excess risks in both sexes were seen for cancers of the colon, larynx, lung and bladder, and in men also for cancers of the prostate and testis. Notably high risks, 10-fold to 30-fold above expectation, were associated with cancers of the lip, skin (non-melanoma), kidney and endocrine glands, also with non-Hodgkin's lymphoma, and in women also with cancers of the cervix and vulva-vagina. Among a number of donor and recipient variables studied, including tissue types and compatibility (ABO, HLA, DR), age below 45 years at the time of transplantation was the most important determinant for increased risk at most sites. Kidney transplantation increases the risk of cancer in the short and in the long term, consistent with the theory that an impaired immune system allows carcinogenic factors to act. The tumor risk is small in comparison with the benefits of transplants, but patients should be followed up for signs of cancer.

Induction of transplantation tolerance and development of lymphomas in mice: lack of interdependence

Neonatal transplantation tolerance was induced in five different H-2-incompatible donor----recipient mouse strain combinations by the iv injection of semiallogeneic (F1 hybrid) spleen cells. The highest degree of tolerance (expressed by the survival time of the specific test skin allografts) was observed in the (CBA X A)F1----CBA combination (approximately 95% permanent tolerance) but some degree of tolerance was achieved in all strain combinations. An increased incidence of malignant lymphoproliferative disorders was observed in all groups of mice which underwent neonatal tolerance induction. The highest incidence of lymphoproliferative malignancies was observed in the (B10 X A)F1----A tolerance induction system, in which approximately 50% of the recipient mice died within 1 year. In further experiments, spleen cells of mice which proved to be permanently tolerant after the neonatal tolerance induction were transferred into syngeneic, normal, adult, ATS-pretreated, allografted recipients; by this method, in approximately 50% of the recipients permanent "adult" tolerance was achieved. The spleen cells of the "adult" tolerant mice were able to transfer the tolerance to other adult, syngeneic, ATS-pretreated recipients. Even the fourth serial transfer resulted in essentially the same degree of tolerance in the new recipients. We consider the serial transfer a classical instance of "infectious tolerance" based on suppressor mechanisms. However, an increasing number (and malignancy) of lymphomas occurred in the course of the serial transfers and prevented the "indefinite" transfer of tolerance after the fourth occasion. We conclude that both the degree of transplantation tolerance and the high frequency of lymphomas are determined by (immuno)genetic factors but the two phenomena are not interrelated. Thus, successful transplantations do not seem to be necessarily accompanied by an increased incidence of malignancies.