Cancer incidence and risk factors after solid organ transplantation

Shifting the paradigm in radiation safety

The current radiation safety paradigm using the linear no-threshold (LNT) model is based on the premise that even the smallest amount of radiation may cause mutations increasing the risk of cancer. Autopsy studies have shown that the presence of cancer cells is not a decisive factor in the occurrence of clinical cancer. On the other hand, suppression of immune system more than doubles the cancer risk in organ transplant patients, indicating its key role in keeping occult cancers in check. Low dose radiation (LDR) elevates immune response, and so it may reduce rather than increase the risk of cancer. LNT model pays exclusive attention to DNA damage, which is not a decisive factor, and completely ignores immune system response, which is an important factor, and so is not scientifically justifiable. By not recognizing the importance of the immune system in cancer, and not exploring exercise intervention, the current paradigm may have missed an opportunity to reduce cancer deaths among atomic bomb survivors. Increased antioxidants from LDR may reduce aging-related non-cancer diseases since oxidative damage is implicated in these. A paradigm shift is warranted to reduce further casualties, reduce fear of LDR, and enable investigation of potential beneficial applications of LDR.

Subsequent cancers in patients diagnosed with cancer of unknown primary (CUP): etiological insights?

BACKGROUND

Patterns of subsequent malignancies in patients with cancer of unknown primary (CUP) may provide etiological insight into the primary tumor. The objective of the present study is to quantify risks of the subsequent cancers in CUP patients since such studies are lacking.

PATIENTS AND METHODS

A population-based cohort of CUP was identified from the Swedish Family-Cancer Database of year 2008. Standardized incidence ratios (SIRs) were calculated for developing the following malignancies in 31,357 CUP patients from 1975 to 2008.

RESULTS

A total of 755 CUP patients developed subsequent cancers, showing a significantly increased overall SIR of 1.69 (95% confidence interval 1.57-1.81). Among the most common 32 malignancies, increased SIRs were noted for 16 sites. Over 10-fold increases were observed for squamous cell carcinoma at four sites, possibly as a result of uncontrolled human papillomavirus infection due to faltering immune surveillance. The highest SIRs were observed among CUP patients diagnosed at a younger age and during the first follow-up year.

CONCLUSIONS

Swedish CUP survivors had a higher risk of developing many subsequent cancers. Different patterns of risk excess may be suggestive of possible roles for disease- and therapy-related immunosuppression, reappearance of hidden primary tumors, or genetic predisposition.

Nucleic acid adjuvants: toward an educated vaccine

Two striking facts surround the practice of vaccination: It is the sole medical approach to have fully annihilated a disease, yet the development of most effective vaccines took place without considering the intricate cellular processes they wish to effectuate. While extremely potent vaccines have been developed that can protect practically a lifetime after a single dose, numerous other vaccines have utterly failed or provide only marginal protection. Here, we aim to illustrate why this difference in efficacy exists, and underline why specific cytotoxic T cell-inducing vaccines could combat persistent major diseases. Moreover, we discuss how the combinatorial use of nucleic acid adjuvants in vaccines could aid the development of the latter and move vaccine design from the empirical stage into an era of "educated design."

Spectrum of cancer risk among US solid organ transplant recipients

CONTEXT

Solid organ transplant recipients have elevated cancer risk due to immunosuppression and oncogenic viral infections. Because most prior research has concerned kidney recipients, large studies that include recipients of differing organs can inform cancer etiology.

OBJECTIVE

To describe the overall pattern of cancer following solid organ transplantation.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study using linked data on solid organ transplant recipients from the US Scientific Registry of Transplant Recipients (1987-2008) and 13 state and regional cancer registries.

MAIN OUTCOME MEASURES

Standardized incidence ratios (SIRs) and excess absolute risks (EARs) assessing relative and absolute cancer risk in transplant recipients compared with the general population.

RESULTS

The registry linkages yielded data on 175,732 solid organ transplants (58.4% for kidney, 21.6% for liver, 10.0% for heart, and 4.0% for lung). The overall cancer risk was elevated with 10,656 cases and an incidence of 1375 per 100,000 person-years (SIR, 2.10 [95% CI, 2.06-2.14]; EAR, 719.3 [95% CI, 693.3-745.6] per 100,000 person-years). Risk was increased for 32 different malignancies, some related to known infections (eg, anal cancer, Kaposi sarcoma) and others unrelated (eg, melanoma, thyroid and lip cancers). The most common malignancies with elevated risk were non-Hodgkin lymphoma (n = 1504; incidence: 194.0 per 100,000 person-years; SIR, 7.54 [95% CI, 7.17-7.93]; EAR, 168.3 [95% CI, 158.6-178.4] per 100,000 person-years) and cancers of the lung (n = 1344; incidence: 173.4 per 100,000 person-years; SIR, 1.97 [95% CI, 1.86-2.08]; EAR, 85.3 [95% CI, 76.2-94.8] per 100,000 person-years), liver (n = 930; incidence: 120.0 per 100,000 person-years; SIR, 11.56 [95% CI, 10.83-12.33]; EAR, 109.6 [95% CI, 102.0-117.6] per 100,000 person-years), and kidney (n = 752; incidence: 97.0 per 100,000 person-years; SIR, 4.65 [95% CI, 4.32-4.99]; EAR, 76.1 [95% CI, 69.3-83.3] per 100,000 person-years). Lung cancer risk was most elevated in lung recipients (SIR, 6.13 [95% CI, 5.18-7.21]) but also increased among other recipients (kidney: SIR, 1.46 [95% CI, 1.34-1.59]; liver: SIR, 1.95 [95% CI, 1.74-2.19]; and heart: SIR, 2.67 [95% CI, 2.40-2.95]). Liver cancer risk was elevated only among liver recipients (SIR, 43.83 [95% CI, 40.90-46.91]), who manifested exceptional risk in the first 6 months (SIR, 508.97 [95% CI, 474.16-545.66]) and a 2-fold excess risk for 10 to 15 years thereafter (SIR, 2.22 [95% CI, 1.57-3.04]). Among kidney recipients, kidney cancer risk was elevated (SIR, 6.66 [95% CI, 6.12-7.23]) and bimodal in onset time. Kidney cancer risk also was increased in liver recipients (SIR, 1.80 [95% CI, 1.40-2.29]) and heart recipients (SIR, 2.90 [95% CI, 2.32-3.59]).

CONCLUSION

Compared with the general population, recipients of a kidney, liver, heart, or lung transplant have an increased risk for diverse infection-related and unrelated cancers.

Treatment of kidney transplant recipients with ACEi/ARB and risk of respiratory tract cancer: a collaborative transplant study report

Whether treatment with angiotensin-converting enzyme inhibitors (ACEi) and/or angiotensin receptor blockers (ARB) increases the risk of cancer is controversial. Collaborative transplant study data were analyzed according to whether kidney transplant recipients were treated with ACEi/ARB at year 1. Twenty-four thousand and ninety patients were studied of whom 9079 (38%) patients received ACEi/ARB. There were 872 nonskin malignancies during years 2-8 posttransplant, including 107 respiratory/intrathoracic tumors. The standardized incidence ratio (SIR) for all nonskin malignancies was similar between the ACEi/ARB (1.91) and no ACEi/ARB (1.81) groups (p = 0.42). For respiratory/intrathoracic tumors, however, SIR was significantly higher with ACEi/ARB (1.65 vs. 1.09 for no ACEi/ARB, p = 0.033). Multivariate Cox regression analysis showed that ACEi/ARB treatment was not associated with an increased risk of respiratory/intrathoracic tumors in nonsmokers. In patients with a history of smoking, however, the risk of respiratory/intrathoracic tumors was 2.77 (95% CI 1.19-6.43, p = 0.018) in patients without ACEi/ARB treatment as compared to 7.10 (95% CI 3.27-15.4, p < 0.001) in patients treated with ACEi/ARB. Our data indicate that in kidney transplant recipients, ACEi/ARB treatment is associated with a significant increase in the rate of respiratory/intrathoracic tumors in the subpopulation of patients with a history of smoking.

Chronic myeloproliferative neoplasms and subsequent cancer risk: a Danish population-based cohort study

Patients with chronic myeloproliferative neoplasms, including essential thrombocythemia (ET), polycythemia vera (PV), and chronic myeloid leukemia (CML), are at increased risk of new hematologic malignancies, but their risk of nonhematologic malignancies remains unknown. In the present study, we assessed the risk of both types of malignancies after an ET, PV, or CML diagnosis. We linked 2 population-based nationwide registries, the Danish National Registry of Patients, covering all Danish hospitals and the Danish Cancer Registry, and assessed subsequent cancer risk in a cohort of all 7229 patients diagnosed with a chronic myeloproliferative neoplasm during 1977-2008. We compared the incidence of subsequent cancer in this cohort with that expected on the basis of cancer incidence in the general population (standardized incidence ratio). Overall, ET, PV, and CML patients were at increased risk of developing both new hematologic and nonhematologic cancers. The standardized incidence ratio for developing a nonhematologic cancer was 1.2 (95% confidence interval [95% CI]): 1.0-1.4) for patients with ET, 1.4 (95% CI: 1.3-1.5) for patients with PV, and 1.6 (95% CI: 1.3-2.0) for patients with CML. We conclude that patients with chronic myeloproliferative neoplasms are at increased risk of developing a new malignant disease.

Commentary: does immune suppression increase risk of developing acute myeloid leukemia?

Risk of developing some cancers is markedly increased in settings of immune suppression including after solid organ transplants and in persons with inherited immune-deficiency disorders and those with HIV-1 infection. These cancers include lymphomas, melanoma and non-melanoma skin cancers, kidney and cervical cancers, Kaposi sarcoma and neuroblastoma. There are no reports of an increased acute myeloid leukemia (AML) in settings of immune suppression. This is curious because some data suggest the immune suppression may be important in increasing AML risk in experimental settings, and that immune stimulation may be useful in treating AML. To see whether immune suppression is correlated with an increased risk of developing AML, we analyzed data from 248224 recipients of kidney (N=217219) and heart (N=31005) transplants. Among the kidney transplant recipients, the standardized incidence ratio (SIR) for developing AML was 1.90 (95% confidence interval, 1.4-2.4; P<0.001). Among the heart transplant recipients, the SIR was 5.1 (3.4-7.1; P<0.001). These data suggest immune suppression increases risk of developing AML and that this risk is even higher, following intense prolonged immune suppression. Implications for AML development and therapy are discussed.

High throughput sequencing reveals diversity of Human Papillomaviruses in cutaneous lesions

There are at least 120 completely characterized human papillomavirus (HPV) types and putative new types are continuously found. Both squamous cell carcinoma of the skin (SCC) and other skin lesions commonly contain multiple cutaneous HPV types. The objective of this study was to achieve an improved resolution of the diversity of HPV types in lesions such as SCCs, actinic keratoses (AKs) and keratoacanthomas (KAs). Fresh frozen biopsies from 37 SCC lesions, 36 AK lesions and 92 KA lesions and swab samples from the top of the lesion from 86 SCCs and 92 AKs were amplified using the general HPV primers FAP and mixed to three pools followed by high throughput sequencing. We obtained 2196 reads with homology to HPV. In the pool of SCC/AK biopsies 48 different HPV types were found. Eighty-three types were found in the pool of SCC/AK swab samples and 64 types in the KA biopsies, respectively. For 9 novel putative HPV types most of the amplimer sequence was obtained, whereas for an additional 35 novel putative HPV types only partial amplimer sequences were obtained. Most of the novel putative types belonged to the genus Gamma. In conclusion, high throughput sequencing was an effective means to identify both known and previously unknown HPV types in putatively HPV-associated lesions and has revealed an extended diversity of HPV types.

Autoimmune disease and subsequent digestive tract cancer by histology

BACKGROUND

Dysregulation of the immune function in autoimmune diseases could potentially lead to cancer development and there is definite evidence linking some autoimmune mechanisms with cancer. We analyzed systematically the occurrence of histology-specific digestive tract cancers in patients diagnosed with 33 different autoimmune diseases in order to address the question of shared susceptibility.

PATIENTS AND METHODS

Standardized incidence ratios (SIRs) were calculated for subsequent digestive tract cancers up to the year 2008 and in patients hospitalized for autoimmune disease after the year 1964.

RESULTS

Myasthenia gravis associated with five different cancers with SIRs ranging from 1.35 to 2.78. Pernicious anemia, Crohn disease, ulcerative colitis, systemic lupus erythematosis and psoriasis were also associated with cancers at multiple sites. Rheumatoid arthritis associated with no cancer and the standardized incidence ratio was decreased for colon adenocarcinoma, also in ankylosing spondylitis patients.

CONCLUSIONS

Increased risks of cancer were observed in patients with several autoimmune diseases. Myasthenia gravis and pernicious anemia were associated with many cancers; this is possibly related to immunosuppressant medication in myasthenia gravis. The decreased risks in colon and rectal adenocarcinomas in rheumatoid arthritis and ankylosing spondylitis suggest underlying inflammatory mechanisms as the risks may have been suppressed by the use of anti-inflammatory medication.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

Safety and feasibility of third-party multipotent adult progenitor cells for immunomodulation therapy after liver transplantation--a phase I study (MISOT-I)

BACKGROUND

Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs.

METHODS

Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n = 3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each).

DISCUSSION

If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy.

Treating rheumatic patients with a malignancy

Management of patients with inflammatory rheumatic disease and a history of (or even a current) malignant disease poses some particular challenges. As direct evidence of the risk of (recurrent or de novo) malignancy in patients with a history of malignant disease is scarce, such a risk may be estimated indirectly from the principal carcinogenicity of the respective drug to be used or (also indirectly) from cancer reactivation data from the transplant literature. In general, cancer risk is increased in patients receiving combination immunosuppressive treatment, but the risk in patients receiving individual drugs (with the exception of alkylating agents) remains entirely unclear. Indirect evidence supports the intuitive concept that the risk of cancer decreases over time after a successful cancer treatment. The only two studies in rheumatic patients with a cancer history were small and have not been able to show an increase in cancer reactivation. The risk of reactivation also depends on the site and location of the prior malignancy. In conclusion, the decision to treat a patient with a history of cancer immunosuppressively should be shared by the rheumatologist and the oncologist. Once the decision is established, such patients need intensive and close monitoring.

Prevention and treatment of papillomavirus-related cancers through immunization

Cervical and other anogenital cancers are initiated by infection with one of a small group of human papillomaviruses (HPV). Virus-like particle-based vaccines have recently been developed to prevent infection with two cancer-associated HPV genotypes (HPV16, HPV18) and have been ∼95% effective at preventing HPV-associated disease caused by these genotypes in virus-naive subjects. Although immunization induces virus-neutralizing antibody sufficient to prevent infection, persistence of antibody as measured by current assays does not appear necessary to maintain protection over time. Investigators have not identified a reliable surrogate immunological marker of protection against disease following immunization. The prophylactic vaccines are not therapeutic for existing infection. Trials of HPV-specific immunotherapy have shown some efficacy for existing disease, although animal modeling suggests that a combination of immunization and local enhancement of innate immunity may be necessary for optimal therapeutic outcome. HPV prophylactic vaccines are the first vaccines designed to prevent a human cancer and are the practical outcome of a global collaborative effort between basic and applied scientists, clinicians, and industry.

Hallmarks of cancer: the next generation

The hallmarks of cancer comprise six biological capabilities acquired during the multistep development of human tumors. The hallmarks constitute an organizing principle for rationalizing the complexities of neoplastic disease. They include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis. Underlying these hallmarks are genome instability, which generates the genetic diversity that expedites their acquisition, and inflammation, which fosters multiple hallmark functions. Conceptual progress in the last decade has added two emerging hallmarks of potential generality to this list-reprogramming of energy metabolism and evading immune destruction. In addition to cancer cells, tumors exhibit another dimension of complexity: they contain a repertoire of recruited, ostensibly normal cells that contribute to the acquisition of hallmark traits by creating the "tumor microenvironment." Recognition of the widespread applicability of these concepts will increasingly affect the development of new means to treat human cancer.

Solid-organ transplantation in childhood: transitioning to adult health care

Pediatric solid-organ transplantation is an increasingly successful treatment for solid-organ failure. With dramatic improvements in patient survival rates over the last several decades, there has been a corresponding emergence of complications attributable to pretransplant factors, transplantation itself, and the management of transplantation with effective immunosuppression. The predominant solid-organ transplantation sequelae are medical and psychosocial. These sequelae have a substantial effect on transition to adult care; as such, hurdles to successful transition of care arise from the patients, their families, and pediatric and adult health care providers. Crucial to successful transitioning is the ongoing development of a sense of autonomy and responsibility for one's own care. In this article we address the barriers to transitioning that occur with long-term survival in pediatric solid-organ transplantation. Although a particular transitioning model is not promoted, practical tools and strategies that contribute to successful transitioning of pediatric patients who have received a transplant are suggested.

[Challenges in the organization of investigator initiated trials: in transplantation medicine]

INTRODUCTION

Transplantation medicine offers multiple translational questions which should preferably be transferred to clinical evidence. The current gold standard for testing such questions and hypotheses is by prospective randomized controlled trials (RCT). The trials should be performed independently from the medical industry to avoid conflicts of interests and to guarantee a strict scientific approach. A good model is an investigator initiated trial (IIT) in which academic institutions function as the sponsor and in which normally a scientific idea stands before marketing interests of a certain medical product.

METHODS

We present a model for an IIT which is sponsored and coordinated by Regensburg University Hospital at 45 sites in 13 nations (SiLVER study), highlight special pitfalls of this study and offer alternatives to this approach.

RESULTS

Finances: financial support in clinical trials can be obtained from the medical industry. Alternatively in Germany the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung) offers annual grants. The expansion of financial support through foundations is desirable. Infrastructure: sponsorship within the pharmaceutics act (Arzneimittelgesetz) demands excellent infrastructural conditions and a professional team to accomplish clinical, logistic, regulatory, legal and ethical challenges in a RCT. If a large trial has sufficient financial support certain tasks can be outsourced and delegated to contract research organizations, coordinating centers for clinical trials or partners in the medical industry.

CONCLUSIONS

Clinical scientific advances to improve evidence are an enormous challenge when performed as an IIT. However, academic sponsors can perform (international) IITs when certain rules are followed and should be defined as the gold standard when scientific findings have to be established clinically.

Outcomes in pediatric solid-organ transplantation

LaR Pediatric solid-organ transplantation is an increasingly successful treatment for organ failure. Five- and 10-yr patient survival rates have dramatically improved over the last couple of decades, and currently, over 80% of pediatric patients survive into adolescence and young adulthood. Waiting list mortality has been a concern for liver, heart, and intestinal transplantation, illustrating the importance of transplant as a life-saving therapy. Unfortunately, the success of pediatric transplantation comes at the cost of long-term or late complications that arise as a result of allograft rejection or injury, immunosuppression-related morbidity, or both. As transplant recipients enter adolescence treatment, non-adherence becomes a significant issue, and the medical and psychosocial impacts transition to adulthood not only with regard to healthcare but also in terms of functional outcomes, economic potential, and overall QoL. This review addresses the clinical and psychosocial challenges encountered by pediatric transplant recipients in the current era. A better understanding of pediatric transplant outcomes and adult morbidity and mortality requires further ongoing assessment.

Characteristics of thoracic malignancies that occur after solid-organ transplantation

BACKGROUND

Chronic immunosuppression after solid-organ transplantation is associated with increased risk of developing malignancies. The purpose of this study was to determine the clinical characteristics and the outcome of thoracic malignancies in patients who have undergone solid-organ transplantation.

METHODS

Among a cohort of 2831 patients who received a transplant at our institution and were followed between 1984 and 2009, 24 patients (0.85%) developed thoracic malignancies. Risk factors for lung cancer, as well as demographic, cancer, and transplantation characteristics, were analyzed. Survival data were also collected.

RESULTS

Twenty-four patients were included (21 men, median age 61.7 years). Twenty-two patients were smokers. The most frequent histologic types were squamous cell carcinoma (n = 11, 46%) and adenocarcinoma (n = 9, 37%). The median time period between transplantation and diagnosis of lung cancer was 6.6 years. Ten lung malignancies occurred after kidney transplantation (0.5%), eight after liver transplantation (1.3%), and six after heart transplantation (2.8%). Seven patients underwent surgery, three had radiotherapy, four had chemotherapy, and six had multimodal treatment. The median survival time was 1.5 years, ranging from 6 months for stage IV to 3.7 years for stage I.

CONCLUSION

Solid-organ transplantation is associated with a high risk of lung cancer and may have an important synergetic part with other risk factors for lung cancer (tobacco). However, survival rates from lung cancer in our study population are similar to those of nontransplanted patients. In addition, surgery can result in favorable survival results.

Biological agents in kidney transplantation: belatacept is entering the field

IMPORTANCE OF THE FIELD

Kidney transplantation is the best treatment for end-stage kidney-disease patients. However, despite major breakthroughs in the last decades, and the progresses made with immunosuppressants, the long-term results still need to be improved. This is related to the increased risk of cardiovascular mortality, de novo post-transplant malignancies, and chronic kidney disease within the allograft. The last is multifactorial and includes immunological and non-immunological factors. Amongst the last is the calcineurin inhibitor (CNI) (cyclosporine A (CsA) and tacrolimus)-related nephrotoxicity. Kidney-allograft function at 1-year post-transplantation is a good surrogate marker of long-term allograft survival.

AREAS COVERED IN THIS REVIEW

Cytotoxic T-lymphocyte-associated antigen 4 (CTLA4)-Ig, a fusion protein, presents as abatacept, which conserves the natural structure of CTLA4, and belatacept, which has enhanced activity thanks to two amino-acid substitutions. Abatacept and belatacept block CD86-CD28 interaction, but belatacept blocks them more powerfully. Abatacept is already approved for the treatment of rheumatoid arthritis and is marketed as Orencia(®) (Bristol-Myers Squibb, Princeton, NJ, USA), whereas belatacept is not yet approved. Herein, we review the current data available on the use of belatacept in Phase II and III kidney-transplantation trials. Note, though, that data from belatacept Phase II liver transplantation trials are not yet available.

WHAT THE READER WILL GAIN

The results show in de novo kidney transplant patients that as compared to CsA-treated patients, belatacept-treated patients showed: i) a significant better allograft function both at 1- and 2- year post-transplantation and ii) better cardiovascular and metabolic profiles. Regarding the safety data, Epstein-Barr virus (EBV) seronegative belatacept-treated patients experience more post-transplant lymphoproliferative disorders than the EBV seropositive belatacept-treated patients and the CsA-treated patients.

TAKE HOME MESSAGE

CNIs are potent immunosuppressants but have some degree of nephrotoxicity. Therefore, it is important to have strong data showing that belatacept-based therapy is as efficient as CsA-based therapy, but displaying at both 1- and 2-year post-transplantation a better allograft function, which might translate in the long-term into longer allograft survival.

Unresolved questions concerning human papillomavirus infection and transmission: a modelling perspective

Mathematical transmission models are widely used to forecast the potential impact of interventions such as vaccination and to inform the development of health policy. Effective vaccines are now available for the prevention of cervical cancer and other diseases attributable to human papillomavirus (HPV). Considerable uncertainties remain regarding the characterisation of HPV infection and its sequelae, infectivity, and both vaccine-conferred and naturally-acquired immunity. In this review, we discuss the key knowledge gaps that impact on our ability to develop accurate models of HPV transmission and vaccination.

Why do viruses cause cancer? Highlights of the first century of human tumour virology

The year 2011 marks the centenary of Francis Peyton Rous's landmark experiments on an avian cancer virus. Since then, seven human viruses have been found to cause 10-15% of human cancers worldwide. Viruses have been central to modern cancer research and provide profound insights into both infectious and non-infectious cancer causes. This diverse group of viruses reveals unexpected connections between innate immunity, immune sensors and tumour suppressor signalling that control both viral infection and cancer. This Timeline article describes common features of human tumour viruses and discusses how new technologies can be used to identify infectious causes of cancer.

Hodgkin lymphoma among US solid organ transplant recipients

BACKGROUND

To assess the risk and identify risk factors of Hodgkin lymphoma (HL) in solid organ transplant recipients. Prior research has been limited by the rarity of HL and the requirement for extended follow-up after transplantation.

METHODS

Using data from the Scientific Registry of Transplant Recipients (SRTR), we conducted a retrospective cohort study of US solid organ transplant recipients (1997-2007). We estimated hazard ratios (HRs) for HL risk factors using proportional hazards regression. Standardized incidence ratios (SIRs) compared HL risk in the transplant cohort with the general population.

RESULTS

The cohort included 283,190 transplant recipients (average follow-up: 3.7 years after transplantation). Based on 73 cases, HL risk factors included male gender (HR: 2.1, 95% CI: 1.2-3.7), young age (4.0, 2.3-6.8), and Epstein-Barr virus (EBV) seronegativity at the time of transplantation (3.1, 1.2-8.1). Among tumors with EBV status information, 79% were EBV positive, including all tumors in recipients who were initially seronegative. Overall, HL risk was higher than in the general population (SIR: 2.2) and increased monotonically over time after transplantation (SIR: 4.1 at 8-10 years posttransplant). Excess HL risk was especially high after heart and/or lung transplantation (SIR: 3.2).

CONCLUSION

HL is a late complication of solid organ transplantation. The high HL risk in recipients who were young or EBV seronegative at the time of transplant and the fact that most HL tumors were EBV positive highlight the role of primary EBV infection and poor immune control of this virus. The occurrence of HL may rise with improved long-term survival in transplant recipients.

Asthma, Asthma Medications, and Prostate Cancer Risk

Background: The aim of this study was to assess whether a history of asthma or the use of asthma medications is associated with prostate cancer risk.

Methods: Of 16,934 men participating in the Melbourne Collaborative Cohort Study, 1,179 were diagnosed with prostate cancer during an average follow-up of 13.4 years to the end of December 2007. Information on asthma history was obtained at baseline interview. Participants were asked to bring their current medications to the study center. The names of the drugs were entered into a form and coded. Asthma medications were categorized into four groups and corresponding hazard ratios (HR) were estimated from Cox regression models adjusted for country of birth.

Results: Asthma was associated with a small increase in prostate cancer risk [HR 1.25; 95% confidence interval (95% CI), 1.05-1.49]. The HRs for use of medications were 1.39 (95% CI, 1.03-1.88) for inhaled glucocorticoids, 1.71 (95% CI, 1.08-2.69) for systemic glucocorticoids, 1.36 (95% CI, 1.05-1.76) for bronchodilators, and 0.78 (95% CI, 0.45-1.35) for antihistamines. The HRs for asthma and asthma medication use changed only slightly after mutual adjustment.

Conclusions: A history of asthma and the use of asthma medications, particularly systemic glucocorticoids, are associated with an increased risk of prostate cancer, although it is difficult to disentangle the effects of asthma medications from those of asthma per se.

Impact: These findings, if confirmed in independent studies, might lead to the identification of new risk factors for prostate cancer. Cancer Epidemiol Biomarkers Prev; 19(9); 2318–24. ©2010 AACR.

Incidence of cancer in kidney-transplant recipients: a long-term cohort study in a single center

In a long-term cohort study, we calculated cancer incidences and survival rates after the development of these cancers in kidney-transplant recipients. The cancer incidences were compared with those in the general population. The occurrence of cancer was recorded in all patients who received kidney transplantation between 1966 and 2006. The median follow-up time was more than 9 years with a maximum of almost 40 years. Altogether 327 (17%) of 1906 patients developed cancer after transplantation: 142 (7%) had non-cutaneous malignancies; 178 (9%) cutaneous squamous-cell carcinomas and 138 (7%) basal-cell carcinomas. The cumulative incidence of any cancer was 13%, 33% and 47% after 10, 20 and 30 years, respectively. The incidences of cancers of the oral cavity, stomach, female genital organs, kidney, thyroid gland, leukemias and lymphomas, and cutaneous squamous-cell carcinoma were significantly increased with a highest standardized morbidity ratio of 40 for cutaneous squamous-cell carcinomas. Survival rates after non-cutaneous malignancies were 57%, 43% and 36% and after non-melanocytic skin cancer 99%, 90% and 77% after 1, 3 and 5 years, respectively. The increased incidence of non-cutaneous malignancies after kidney transplantation is associated with a high mortality. Prevention of cancer after kidney transplantation should be a major focus of future research.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

Single nucleotide polymorphism-arrays provide new insights in the pathogenesis of post-transplant diffuse large B-cell lymphoma

Post-transplant lymphoproliferative disorders (PTLD) are complications of solid organ transplantation associated with severe morbidity and mortality. Diffuse large B-cell lymphoma (DLBCL) represents the most common form of monomorphic PTLD. We studied 44 cases of post-transplant DLBCL (PT-DLBCL) with high-density genome wide single nucleotide polymorphism-based arrays, and compared them with 105 cases of immunocompetent DLBCL (IC-DLBCL) and 28 cases of Human Immunodeficiency Virus-associated DLBCL (HIV-DLBCL). PT-DLBCL showed a genomic profile with specific features, although their genomic complexity was overall similar to that observed in IC- and HIV-DLBCL. Among the loci more frequently deleted in PT-DLBCL there were small interstitial deletions targeting known fragile sites, such as FRA1B, FRA2E and FRA3B. Deletions at 2p16.1 (FRA2E) were the most common lesions in PT-DLBCL, occurring at a frequency that was significantly higher than in IC-DLBCL. Genetic lesions that characterized post-germinal center IC-DLBCL were under-represented in our series of PT-DLBCL. Two other differences between IC-DLBCL and PT-DLBCL were the lack of del(13q14.3) (MIR15/MIR16) and of copy neutral LOH affecting 6p [major histocompatibility complex (MHC) locus] in the latter group. In conclusion, PT-DLBCL presented unique features when compared with IC-DLBCL. Changes in PT-DLBCL were partially different to those in HIV-DLBCL, suggesting different pathogenetic mechanisms in the two conditions linked to immunodeficiency.

Current status of islet cell replacement and regeneration therapy

CONTEXT

Beta cell mass and function are decreased to varying degrees in both type 1 and type 2 diabetes. In the future, islet cell replacement or regeneration therapy may thus offer therapeutic benefit to people with diabetes, but there are major challenges to be overcome.

EVIDENCE ACQUISITION

A review of published peer-reviewed medical literature on beta-cell development and regeneration was performed. Only publications considered most relevant were selected for citation, with particular attention to the period 2000-2009 and the inclusion of earlier landmark studies.

EVIDENCE SYNTHESIS

Islet cell regenerative therapy could be achieved by in situ regeneration or implantation of cells previously derived in vitro. Both approaches are being explored, and their ultimate success will depend on the ability to recapitulate key events in the normal development of the endocrine pancreas to derive fully differentiated islet cells that are functionally normal. There is also debate as to whether beta-cells alone will assure adequate metabolic control or whether it will be necessary to regenerate islets with their various cell types and unique integrated function. Any approach must account for the potential dangers of regenerative therapy.

CONCLUSIONS

Islet cell regenerative therapy may one day offer an improved treatment of diabetes and potentially a cure. However, the various approaches are at an early stage of preclinical development and should not be offered to patients until shown to be safe as well as more efficacious than existing therapy.

Inflammation and cancer: interweaving microRNA, free radical, cytokine and p53 pathways

Chronic inflammation and infection are major causes of cancer. There are continued improvements to our understanding of the molecular connections between inflammation and cancer. Key mediators of inflammation-induced cancer include nuclear factor kappa B, reactive oxygen and nitrogen species, inflammatory cytokines, prostaglandins and specific microRNAs. The collective activity of these mediators is largely responsible for either a pro-tumorigenic or anti-tumorigenic inflammatory response through changes in cell proliferation, cell death, cellular senescence, DNA mutation rates, DNA methylation and angiogenesis. As our understanding grows, inflammatory mediators will provide opportunities to develop novel diagnostic and therapeutic strategies. In this review, we provide a general overview of the connection between inflammation, microRNAs and cancer and highlight how our improved understanding of these connections may provide novel preventive, diagnostic and therapeutic strategies to reduce the health burden of cancer.