Immunosuppression and other risk factors for lip cancer after kidney transplantation

Relative carcinogenicity of tacrolimus vs mycophenolate after solid organ transplantation and its implications for liver transplant care

BACKGROUND

De novo malignancy is a leading cause of late morbidity and mortality in liver transplant recipients. Cumulative immunosuppression has been shown to contribute to post-transplant malignancy (PTM) risk. There is emerging evidence on the differential carcinogenic risk profile of individual immunosuppressive drugs, independent of the net effect of immunosuppression. Calcineurin inhibitors such as tacrolimus may promote tumourigenesis, whereas mycophenolic acid (MPA), the active metabolite of mycophenolate mofetil, may limit tumour progression. Liver transplantation (LT) is relatively unique among solid organ transplantation in that immunosuppression monotherapy with either tacrolimus or MPA is often achievable, which makes careful consideration of the risk-benefit profile of these immunosuppression agents particularly relevant for this cohort. However, there is limited clinical data on this subject in both LT and other solid organ transplant recipients.

AIM

To investigate the relative carcinogenicity of tacrolimus and MPA in solid organ transplantation.

METHODS

A literature search was conducted using MEDLINE and Embase databases using the key terms "solid organ transplantation", "tacrolimus", "mycophenolic acid", and "carcinogenicity", in order to identify relevant articles published in English between 1st January 2002 to 11th August 2022. Related terms, synonyms and explosion of MeSH terms, Boolean operators and truncations were also utilised in the search. Reference lists of retrieved articles were also reviewed to identify any additional articles. Excluding duplicates, abstracts from 1230 records were screened by a single reviewer, whereby 31 records were reviewed in detail. Full-text articles were assessed for eligibility based on pre-specified inclusion and exclusion criteria.

RESULTS

A total of 6 studies were included in this review. All studies were large population registries or cohort studies, which varied in transplant era, type of organ transplanted and immunosuppression protocol used. Overall, there was no clear difference demonstrated between tacrolimus and MPA in de novo PTM risk following solid organ transplantation. Furthermore, no study provided a direct comparison of carcinogenic risk between tacrolimus and MPA monotherapy in solid organ transplantation recipients.

CONCLUSION

The contrasting carcinogenic risk profiles of tacrolimus and MPA demonstrated in previous experimental studies, and its application in solid organ transplantation, is yet to be confirmed in clinical studies. Thus, the optimal choice of immunosuppression drug to use as maintenance monotherapy in LT recipients is not supported by a strong evidence base and remains unclear.

Time trends in cancer incidence in Australian people living with HIV between 1982 and 2012

OBJECTIVES

The aim of the study was to describe time trends in cancer incidence in people living with HIV (PLHIV) in Australia between 1982 and 2012.

METHODS

A population-based prospective study was conducted using data linkage between the national HIV and cancer registries. Invasive cancers identified in PLHIV were grouped into AIDS-defining cancers (ADCs), infection-related non-ADCs (NADCs), and non-infection-related NADCs. Crude and age-standardized incidence rates of cancers were calculated and compared over five time periods: 1982-1995, 1996-1999, 2000-2004, 2005-2008 and 2009-2012, roughly reflecting advances in HIV antiretroviral therapy. Standardized incidence ratios (SIRs) compared with the Australian general population were calculated for each time period. Generalized linear models were developed to assess time trends in crude and age-standardized incidences.

RESULTS

For ADCs, the crude and age-standardized incidences of Kaposi sarcoma and non-Hodgkin lymphoma substantially declined over time (P-trend < 0.001 for all) but SIRs remained significantly elevated. For infection-related NADCs, there were significant increases in the crude incidences of anal, liver and head and neck cancers. Age-standardized incidences increased for anal cancer (P-trend = 0.002) and liver cancer (P-trend < 0.001). SIRs were significantly elevated for anal cancer, liver cancer and Hodgkin lymphoma. For non-infection-related NADCs, the crude incidence of colorectal, lung and prostate cancers increased over time, but age-standardized incidences remained stable.

CONCLUSIONS

Continuous improvements and high coverage of antiretroviral therapy have reduced the incidence of ADCs in PLHIV in Australia. Clinical monitoring of anal and liver cancers in people living with HIV should be performed, given the increasing incidence of these cancers.

Pulsed Dose Rate Brachytherapy of Lip Carcinoma: Clinical Outcome and Quality of Life Analysis

Simple Summary

Lip cancer accounts for 25–30% of all oral cancers, with 23,000 new cases per year in the world. Carcinomas of the lip can be successfully treated with different methods: surgery, external beam radiotherapy (EBRT) and brachytherapy. The choice of the treatment depends on the tumor size, location and expected functional and esthetic results with each option, but also depends on treatment type accessibility. There are no randomized studies comparing these different treatment strategies. In this article, we investigated the complications and outcomes of patients treated with interstitial pulsed dose rate brachytherapy in our institution.

Abstract

Purpose: Lip carcinoma represents one of the most common types of head and neck cancer. Brachytherapy is a highly effective therapeutic option for all stages of lip cancers. We report our experience of pulsed dose rate brachytherapy (PDR) as treatment of lip carcinoma. Methods and Materials: this retrospective single center study included all consecutive patients treated for a lip PDR brachytherapy in our institution from 2010 to 2019. The toxicities and outcomes of the patients were reported, and a retrospective quality of life assessment was conducted by phone interviews (FACT H&N). Results: From October 2010 to December 2019, 38 patients were treated in our institution for a lip carcinoma by PDR brachytherapy. The median age was 73, and the majority of patients presented T1-T2 tumors (79%). The median total dose was 70.14 Gy (range: 60–85 Gy). With a mean follow-up of 35.4 months, two patients (5.6%) presented local failure, and seven patients (19%) had lymph node progression. The Kaplan–Meier estimated probability of local failure was 7.2% (95% CI: 0.84–1) at two and four years. All patients encountered radiomucitis grade II or higher. The rate of late toxicities was low: three patients (8.3%) had grade II fibrosis, and one patient had grade II chronic pain. All patients would highly recommend the treatment. The median FACT H&N total score was 127 out of 148, and the median FACT H&N Trial Outcome Index was 84. Conclusions: This study confirms that an excellent local control rate is achieved with PDR brachytherapy as treatment of lip carcinoma, with very limited late side effects and satisfactory functional outcomes. A multimodal approach should help to improve regional control.

Occupational health and safety in agriculture. A systematic review

Introduction: The prevalence of occupational diseases in the agricultural sector is higher than in other industries, since agricultural workers are at higher risk of exposure to different chemicals and pesticides, and are more prone to occupational accidents.Objective: To conduct a review of recent literature on occupational health and risk in agriculture.Materials and methods: A literature search was conducted in PubMed, SciencieDirect and Scopus using the following search strategy: type of articles: original research papers; language: English; publication period: 2006-2016; search terms: "agricultural health", "agrarian health", "risk factors", "epidemiology", "causality" and "occupational", used in different combinations ("AND" and "OR").Results: The search yielded 350 articles, of which 102 met the inclusion criteria. Moreover, 5 articles were found in grey literature sources and included in the final analysis. Most research on this topic has been conducted in the United States, which produced 91% (97/107) of the articles included.Conclusions: Most studies on health and safety in agriculture focused primarily on the harmful effects of occupational exposure to agrochemicals and pesticides, and the consequences of occupational accidents. However, since more than 90% of these studies come from the United States, a more comprehensive approach to health in agriculture is required, since what is reported here may be far from the reality of other regions, especially Latin America.

Otorhinolaryngological dysfunctions induced by chronic kidney disease in pre- and post-transplant stages

Purpose

Otorhinolaryngological abnormalities are common complications of chronic kidney disease (CKD) and its treatment. The main aim of this study was to provide a brief and precise review of the current knowledge regarding CKD and its treatment-related influence on head and neck organs.

Methods

The Medline and Web of Science databases were searched using the terms “chronic kidney disease”, “kidney transplantation”, “immunosuppression”, “dialysis” in conjunction with “otorhinolaryngological manifestation”. Articles that did not address the topics, low-quality studies, case reports, and studies based on nonsignificant cohorts were excluded, and the full text of remaining high-quality, novel articles were examined and elaborated on.

Results

Patients with CKD are prone to develop sensorineural hearing loss, tinnitus, recurrent epistaxis, opportunistic infections including oropharyngeal candidiasis or rhino-cerebral mucormycosis, taste and smell changes, phonatory and vestibular dysfunctions, deep neck infections, mucosal abnormalities, gingival hyperplasia, halitosis or xerostomia. Immunosuppressive therapy after kidney transplantation increases the risk of carcinogenesis, both related and not-related to latent viral infection. The most commonly viral-related neoplasms observed in these patients are oral and oropharyngeal cancers, whereas the majority of not-related to viral infection tumors constitute lip and thyroid cancers. CKD-related otorhinolaryngological dysfunctions are often permanent, difficult to control, have a significant negative influence on patient’s quality of life, and can be life threatening.

Conclusion

Patients with CKD suffer from a number of otorhinolaryngological CKD-induced complications. The relationship between several otorhinolaryngological complications and CKD was widely explained, whereas the correlation between the rest of them and CKD remains unclear. Further studies on this subject are necessary.

Oral carcinoma development after 23 years of renal transplantation

Renal transplant patients are treated with immunosuppressive drugs that decrease the effectiveness of the immune system, making them more prone to developing cancer. Skin and lip carcinomas are common malignancies encountered after transplantation, whereas oral carcinomas are rare. We report the case of a 51-year-old female Caucasian patient, with no history of smoking, who presented white lesions on the tongue and an ulcerated lesion on the lower lip beginning 4 months prior. Diagnosis of squamous cell carcinoma for both lesions was made following incisional biopsies. Interestingly, the patient reported a renal transplantation 23 years prior, and was maintained on a combination of cyclosporine, mycophenolate sodium and prednisone. The patient also presented a history of several basal and squamous cell carcinomas on sun-exposed areas of the skin. Both lesions were surgically excised. No sign of recurrence or new lesions in the oral cavity have been observed; however, new skin lesions are frequently diagnosed. This case report highlights that oral cancers may occur in transplant patients in the absence of classical risk factors. Thus, clinicians must be aware of the importance of thorough oral examination in transplant patients in routine follow-up.

Head and neck cancer management and cancer stem cells implication

Head and neck squamous cell carcinomas (HNSCCs) arise in the mucosal linings of the upper aerodigestive tract and are heterogeneous in nature. Risk factors for HNSCCs are smoking, excessive alcohol consumption, and the human papilloma virus. Conventional treatments are surgery, radiotherapy, chemotherapy, or a combined modality; however, no international standard mode of therapy exists. In contrast to the conventional model of clonal evolution in tumor development, there is a newly proposed theory based on the activity of cancer stem cells (CSCs) as the model for carcinogenesis. This “CSC hypothesis” may explain the high mortality rate, low response to treatments, and tendency to develop multiple tumors for HNSCC patients. We review current knowledge on HNSCC etiology and treatment, with a focus on CSCs, including their origins, identifications, and effects on therapeutic options.

Risk of lip cancer after solid organ transplantation in the United States

Solid organ transplant recipients have an increased risk of lip cancer, but the reasons are uncertain. Using data from the Transplant Cancer Match Study, we describe the epidemiology of lip cancer among 261 500 transplant recipients in the United States. Two hundred thirty-one lip cancers were identified, corresponding to elevated risks for both invasive and in situ lip cancers (standardized incidence ratios of 15.3 and 26.2, respectively). Invasive lip cancer incidence was associated with male sex (adjusted incidence rate ratio [aIRR] 2.01, 95% CI 1.44-2.82), transplanted organ (0.33, 0.20-0.57, for liver transplants and 3.07, 1.96-4.81, for lung transplants, compared with kidney transplants), and racial/ethnic groups other than non-Hispanic whites (0.09, 0.04-0.2). In addition, incidence increased with age and during the first 3 years following transplant, and was higher in recipients prescribed cyclosporine/azathioprine maintenance therapy (aIRR 1.79, 95% CI 1.09-2.93, compared with use of tacrolimus/mycophenolate mofetil) and following a diagnosis of cutaneous squamous cell carcinoma (4.21, 2.69-0.94). The elevation in lip cancer incidence is consistent with an effect of immunosuppression. Notably, the very strong associations with white race and history of prior skin cancer point to an important role for ultraviolet radiation exposure, and cyclosporine and azathioprine may contribute as photosensitizing or DNA damaging agents.

Characteristics of non-melanoma skin cancers of the cutaneous perioral and vermilion lip treated by Mohs micrographic surgery

BACKGROUND

The lip and surrounding perioral region are susceptible to non-melanoma skin cancer, but the distribution of basal cell and squamous cell carcinoma on the cutaneous and vermilion lips has not been fully elucidated.

OBJECTIVE

To investigate the distribution of cutaneous and vermilion lip non-melanoma skin cancer and to better describe risk factors, anatomic location, treatment characteristics and oncologic outcomes.

METHODS

A retrospective comparative case series of patients undergoing Mohs micrographic surgery (MMS) at a single academic centre for lip and perioral basal cell and squamous cell carcinoma was performed over a 5-year period. Demographics, medical comorbidities, surgical characteristics and recurrence status were extracted.

RESULTS

Forty-five vermilion and 116 cutaneous lip cancers were identified. Basal cell carcinoma (BCC) was more common in the cutaneous perioral region, while squamous cell carcinoma (SCC) was more common on the vermilion lip (P < 0.001). BCCs were more common on the upper vermilion lip and SCCs were more common on the lower vermilion lip (P < 0.001). Within the cutaneous perioral region, both BCCs and SCCs were more common on the upper perioral surface (P = 0.002). Male gender was associated with lower lip SCC (P = 0.015). Smoking, immunosuppression, anticoagulant use and hydrochlorothiazide use were not associated with cancer type or location. Recurrences were rare, but more common in vermilion lip cancers (6.6%) compared to perioral cutaneous cancers (0.8%). Outcomes for all groups were similar; BCCs of the vermilion lip had significantly greater mean MMS stages (P < 0.001) as did SCCs (P = 0.05).

CONCLUSION

Basal cell carcinoma is more commonly encountered on the cutaneous lip, whereas SCC is more common on the vermilion lip. Within the vermilion lip, BCC favours the upper lip, while SCC favours the lower lip. Within the cutaneous perioral region, both BCC and SCC favour the upper cutaneous tissue. Early stage lip cancers are curable by Mohs micrographic surgery with rare recurrences.

Lung cancer in renal transplant recipients: A case-control study

INTRODUCTION

Solid organ transplant patients are at heightened risk of several cancers compared to the general population. Secondary to a higher number of procedures and better survival after transplantation, cancer is a rising health concern in this situation. Limited data exist for lung cancer (LC) after renal transplantation. We report here the most important series of renal transplant recipients with lung cancer.

METHODS

Retrospective study of all cases of LC diagnosed in three French Renal Transplant Units from 2003 to 2012. A control group consisted of non-transplant patients with LC matched with the cases for age (<30; 30-50; 50-65; >65 years), gender and diagnosis date. We recruited two controls for each case.

RESULTS

Thirty patients (median age 60 years; range 29-85; male/female ratio 80/20%) with LC were analysed. LC incidence was 1.89/1000 person-years over the period 2008-2012. All patients were former or active smokers (median 30 pack-years). Transplanted patients had significantly more comorbidities, mainly cardiovascular disease. The median interval of time from kidney transplantation (KT) to diagnosis of LC was 7 years (range 0.5-47 years). LC was incidentally diagnosed in 40%. Most patients (70%) had advanced LC (stage III or IV) disease. Stage of LC at diagnosis was similar in cases and controls. Surgery and chemotherapy were proposed to the same proportion of patients. In cases, mortality was cancer related in 87% and median survival time after diagnosis was 24 months. Survival was not significantly different between the 2 groups.

CONCLUSION

Despite frequent medical and radiological examinations, diagnosis of LC is usually made at an advanced stage and the overall prognosis remains poor.

Oral Cancer: Awareness and Knowledge Among Dental Patients in Riyadh

More than 50 % of oral cancer cases are diagnosed at advanced stages. Public knowledge about oral cancer can help in prevention and early detection of the disease. The aim of the present study was to assess the levels of awareness and knowledge about signs and risk factors of oral cancer among dental patients in Saudi Arabia. A self-administered questionnaire was used to collect information from 1410 randomly selected patients attending dental departments within public hospitals in Riyadh, Saudi Arabia. The collected data were analyzed using SPSS software. The significance level was set at P < 0.05. The study revealed that only 62.4 % were aware of oral cancer. Some 68.2 and 56.5 %, respectively, were able to correctly identify tobacco and alcohol as risk factors. More than two thirds of subjects had no knowledge about any signs of oral cancer. Participants with lower than university education were significantly less aware, and had much less knowledge, of the signs and risk factors of oral cancer. The knowledge regarding oral cancer among Saudi dental patients is alarmingly low. Interventions to improve public knowledge about oral cancer and attitudes towards early diagnosis and treatment are urgently indicated.

De novo cancer in patients on dialysis and after renal transplantation: north-western Italy, 1997-2012

BACKGROUND

Kidney transplant recipients (KTR) are known to have a higher risk of cancer than the general population, especially of malignancies related to oncogenic viral infections. This study assessed the incidence of de novo malignancies (DNMs) in patients receiving kidney transplantation and in dialysis patients (DP) on the waiting list for transplantation at the same centre. The aim was to quantify the contribution of post-transplant immunosuppression to the underlying risk of developing a DNM in dialysis patients on the waiting list for kidney transplant.

METHODS

Cancer incidence rates were computed using the Kaplan-Meier product-limit method. The number of DNMs observed in both groups was compared to the expected incidence in the general Italian population through calculation of the standardized incidence ratios (SIR) and their 95% confidence intervals (CI). To identify risk factors, incidence rate ratios (IRR) and 95% CIs were computed using Poisson regression analysis. The comparison of incidence rates between the two cohorts was also performed using age standardized incidence rates (ASR) and their ratio (age standardized rate ratio, ASRR).

RESULTS

In 4858 person-years (PYs) of observation, 75 out of 735 KTR were diagnosed with DNM: 57 solid neoplasms, 13 post-transplant lymphoproliferative disorders (PTLD), and 12 Kaposi sarcomas (KS). The overall incidence was 17.5 cases/10³ PYs, resulting in a 2.1-fold increased risk. Twenty-four out of 912 DP, over a follow-up of 2400 PYs, were diagnosed with a solid neoplasm, but none had PTLD or KS. The use of induction therapy after transplant was associated with a significant increased risk of KS (IRR: 3.52; 95% CI 1.04-11.98, p < 0.05). ASRR for all cancers and for solid cancers only was 1.84- and 1.19-fold higher in KTR, respectively, than in the general population. The overall incidence in DP was 10.0 cases/10³ PYs, with a 1.6 significantly increased cancer risk compared to the general population.

CONCLUSION

Our study confirms the increased risk of cancer after transplantation and during dialysis, but showed that virus-related cancers only occur after post-transplant immunosuppression.

Azathioprine and Risk of Skin Cancer in Organ Transplant Recipients: Systematic Review and Meta-Analysis

Azathioprine, a purine antimetabolite immunosuppressant, photosensitizes the skin and causes the production of mutagenic reactive oxygen species. It is postulated to increase the risk of squamous cell carcinoma (SCC) and other skin cancers in organ transplant recipients (OTRs), but evidence from multiple, largely single-center studies to date has been inconsistent. We aimed to resolve the issue of azathioprine's carcinogenicity by conducting a systematic review of the relevant literature and pooling published risk estimates to evaluate the risks of SCC, basal cell carcinoma (BCC), keratinocyte cancers (KCs) overall and other skin cancers in relation to azathioprine treatment. Twenty-seven studies were included in total, with risk estimates from 13 of these studies able to be pooled for quantitative analysis. The overall summary estimate showed a significantly increased risk of SCC in relation to azathioprine exposure (1.56, 95% confidence interval [CI] 1.11-2.18). No significant associations between azathioprine treatment and BCC (0.96, 95% CI 0.66-1.40) or KC (0.84, 95% CI 0.59-1.21) risk were observed. There was significant heterogeneity between studies for azathioprine risk estimates and the outcomes of SCC, BCC and KC. The pooled findings of available evidence support the contention that treatment with azathioprine increases the risk of SCC in OTRs.

CD8+ and FoxP3+ T-cell infiltration in actinic cheilitis

BACKGROUND

Differences in immune profile between actinic cheilitis (AC), a precursor of lip squamous cell carcinoma, and normal lip vermillion (NL) have not been elucidated.

OBJECTIVES

To compare density, distribution, and ratios of CD8+ and FoxP3+ cells between AC and NL and assess their associations with clinicopathologic variables.

METHODS

Samples of AC and NL obtained between 2001 and 2013 at the College of Dentistry of the University of Concepcion, Chile, were retrospectively analyzed for immunohistochemical detection of CD8+ and FoxP3+ cells. Differences between groups were tested by Mann-Whitney U and Fisher's exact tests. Independent effects of cell densities and CD8/FoxP3 ratio with AC were assessed by multiple logistic regression analysis after adjustment for potential confounding.

RESULTS

A total of 62 AC and 24 NL biopsies were included. Densities of CD8+ and FoxP3+ cells in AC were significantly higher than in NL. Conversely, the CD8+/FoxP3+ ratio was significantly lower in AC as compared to NL. After adjustment for sun exposure, age, gender, and smoking status, a stromal FoxP3+ cell density higher than 0.35 cells/field was significantly associated with increased odds of AC (odds ratio [OR] = 5.01, 95% confidence interval [CI]: 1.18-21.31), while a stromal CD8+/FoxP3+ ratio higher than 5.91 was associated with decreased odds of AC (OR = 0.29, 95% CI: 0.08-1.08).

CONCLUSIONS

AC is characterized by increased FoxP3+ cell infiltration and a reduced CD8/FoxP3 ratio as compared to NL. Therefore, increased infiltration of FoxP3+ cells relative to CD8+ cells may contribute to the transition from normal to preneoplastic stages in lip carcinogenesis.

Variation in Cancer Incidence among Patients with ESRD during Kidney Function and Nonfunction Intervals

Among patients with ESRD, cancer risk is affected by kidney dysfunction and by immunosuppression after transplant. Assessing patterns across periods of dialysis and kidney transplantation may inform cancer etiology. We evaluated 202,195 kidney transplant candidates and recipients from a linkage between the Scientific Registry of Transplant Recipients and cancer registries, and compared incidence in kidney function intervals (time with a transplant) with incidence in nonfunction intervals (waitlist or time after transplant failure), adjusting for demographic factors. Incidence of infection-related and immune-related cancer was higher during kidney function intervals than during nonfunction intervals. Incidence was most elevated for Kaposi sarcoma (hazard ratio [HR], 9.1; 95% confidence interval (95% CI), 4.7 to 18), non-Hodgkin's lymphoma (HR, 3.2; 95% CI, 2.8 to 3.7), Hodgkin's lymphoma (HR, 3.0; 95% CI, 1.7 to 5.3), lip cancer (HR, 3.4; 95% CI, 2.0 to 6.0), and nonepithelial skin cancers (HR, 3.8; 95% CI, 2.5 to 5.8). Conversely, ESRD-related cancer incidence was lower during kidney function intervals (kidney cancer: HR, 0.8; 95% CI, 0.7 to 0.8 and thyroid cancer: HR, 0.7; 95% CI, 0.6 to 0.8). With each successive interval, incidence changed in alternating directions for non-Hodgkin's lymphoma, melanoma, and lung, pancreatic, and nonepithelial skin cancers (higher during function intervals), and kidney and thyroid cancers (higher during nonfunction intervals). For many cancers, incidence remained higher than in the general population across all intervals. These data indicate strong short-term effects of kidney dysfunction and immunosuppression on cancer incidence in patients with ESRD, suggesting a need for persistent cancer screening and prevention.

High azathioprine dose and lip cancer risk in liver, heart, and lung transplant recipients: A population-based cohort study

BACKGROUND

Iatrogenic immunosuppression is a risk factor for lip cancer but the determinants are unknown.

OBJECTIVE

We sought to quantify the association between the type, dose, and duration of iatrogenic immunosuppression and lip cancer risk in solid organ transplant recipients.

METHODS

We conducted a population-based cohort study of all adult Australian liver, heart, and lung transplant recipients from 1984 to 2006 (n = 4141). We abstracted longitudinal data from medical records and ascertained incident lip cancer (n = 58) and deaths (n = 1434) by linkage with national registries. We estimated multivariable hazard ratios (HR) for lip cancer using the Fine and Gray proportional subdistribution hazards model, accounting for death as a competing risk.

RESULTS

Lip cancer risk (n = 58) increased with high mean daily dose of azathioprine (HR 2.28, 95% confidence interval [CI] 1.18-4.38), longer duration of immunosuppression (HR 9.86, 95% CI 2.10-46.3), increasing year of age at transplantation (HR 1.14, 95% CI 1.04-1.25), earlier transplantation era (HR 8.73, 95% CI 1.11-68.7), and history of smoking (HR 2.71, 95% CI 1.09-6.70).

LIMITATIONS

Data on potential confounders such as personal solar ultraviolet radiation exposure were not available.

CONCLUSION

Higher doses of azathioprine increase lip cancer risk, with implications for managing immunosuppressed populations and our understanding of the relationship between solar ultraviolet radiation and lip cancer.

Mouth Cancer for Clinicians Part 5: Risk Factors (Other)

A MEDLINE search early in 2015 revealed more than 250,000 papers on head and neck cancer; over 100,000 on oral cancer; and over 60,000 on mouth cancer. Not all publications contain robust evidence. We endeavour to encapsulate the most important of the latest information and advances now employed in practice, in a form comprehensible to healthcare workers, patients and their carers. This series offers the primary care dental team, in particular, an overview of the aetiopathogenesis, prevention, diagnosis and multidisciplinary care of mouth cancer, the functional and psychosocial implications, and minimization of the impact on the quality of life of patient and family. Clinical Relevance: This article offers the dental team an overview of other cancer risk factors agents, such as human papilloma viruses (HPV) and irradiation.

Oral potentially malignant disorders among dental patients: a pilot study in Jordan

BACKGROUND

To determine the prevalence, types, and risk factors of oral potentially malignant disorders (OPMDs) among a group of Arab Jordanian dental patients, and to evaluate their awareness and attitudes toward early diagnosis and treatment.

MATERIALS AND METHODS

A total of 1,041 patients attending a University Hospital for dental care were examined for the presence of OPMDs. Histopathological examination was performed on all cases clinically diagnosed and patients were directly interviewed to evaluate their knowledge and attitudes toward early detection and treatment of oral cancer.

RESULTS

The prevalence of OPMDs overall was 2.8%. Lichen planus/lichenoid lesions were the most common lesions (1.8%) followed by leukoplakias (0.48%), chronic hyperplastic candidiosis (0.38%), and erythroplakia (0.096%). Smoking, alcohol, and age (>40 years) were the main identifiable risk factors. Patients with OPMDs displayed a general lack of awareness and negative attitudes towards early diagnosis and treatment.

CONCLUSIONS

OPMDs among Arab dental patients are relatively uncommon and awareness about oral cancer among Jordanian dental patients is low. Interventions to improve public knowledge about oral cancer and attitudes toward early diagnosis and treatment are urgently indicated.

Oral cavity and oropharyngeal squamous cell carcinoma--an update

Oral cavity squamous cell carcinoma (OC-SCC) is the most common malignancy of the head and neck (excluding nonmelanoma skin cancer). Recent trends have shown a dramatic rise in the incidence of oropharyngeal squamous cell carcinoma (OP-SCC), with a marked increase in lesions related to human papillomavirus infection. This update presents the latest evidence regarding OC-SCC and OP-SCC. In particular, the authors compare and contrast tumors at these two sites with respect to epidemiology, etiopathogenesis, clinicopathologic presentation, clinical assessment, imaging, management, and prognosis. It is important for clinicians to be aware of differences between OC-SCC and OP-SCC so that appropriate patient education and multidisciplinary care can be provided to optimize outcomes.

The pattern of lip cancer occurrence over the 1990-2011 period in public hospitals in Madrid, Spain

BACKGROUND

Some regions of Spain along with Canada and Australia have the highest rates of lip cancer in the world. The objective of this study was to examine the trends in the pattern of occurrence of lip cancer in Madrid, Spain.

METHODS

Data were extracted from the Central Tumour Registry of Madrid, between 1990 and 2011. Variables examined were age, sex, topographic and morphological location and tumour histology. Two consecutive periods, 1990-2001 and 2002-2011, were studied by descriptive and analytical methods, and the data from the two periods were statistically compared.

RESULTS

A total of 881 cases were registered during the period 1990-2011. Comparing data between the two periods (1990-2001 and 2002-2011), subtle variations in age, histology and location were noted. Gender ratios remained constant. The mean age increased from 66.3 to 69.7 years (P < 0.05). In the second period, the histological distribution showed an increase in frequency of basal cell carcinoma, from 2.1% to 4.7%, while the frequency of squamous cell carcinomas remained constant. Basal cell carcinoma no longer predominantly occurred in women, decreasing from 80% to 21.1% (P < 0.001). The distribution by gender of squamous cell carcinoma had become more equal due an increase in its frequency in women (P < 0.001). Frequency of tumours on lip mucosa and commissure had increased between the two periods (P < 0.004).

CONCLUSIONS

The pattern of lip cancer reported to Public Hospitals of Madrid is changing: declining rates are noted since 2001-02. However, it is necessary to monitor these data to confirm the observed trends in future years.

Changes in Exfoliative Cell of Oral Mucosa in Kidney Transplant Patients

OBJECTIVES

The aim of this study was to investigate quantitative cytologic changes in oral mucosal smears collected from kidney transplant patients by modern stereologic methods.

METHODS

We enrolled 32 kidney transplant patients. Smears were obtained from the buccal mucosa transplant patients before and 12 months after kidney transplantation. Smears from each individual were stained using the Papanicolaou method and were analyzed using a stereological method.

RESULTS

Statistically, the nuclear volumes and cytoplasmic volumes in the cells of buccal mucosa were markedly higher after kidney transplantation (P < .05). There was a decreased positive cell density in the oral epithelial cells after kidney transplantation compared with before renal transplantation (P < .05).

CONCLUSIONS

These findings suggest that there are alterations in the oral epithelial cells after kidney transplantation, which are detectable by microscopy and cytomorphometry.

Oral Squamous Cell Carcinoma Presenting in a Patient Receiving Adalimumab for Rheumatoid Arthritis

The efficacy of biologic agents in the treatment of inflammatory immune-mediated conditions has been clearly shown, but there also are numerous reports of adverse effects. Most reported adverse effects have been associated with tumor necrosis factor-α (TNF-α) inhibitors and include a possible increased risk of malignancy. There have been some reported cases of oral cancer developing in patients treated with TNF-α inhibitors. This case report describes a patient who was taking adalimumab for rheumatoid arthritis and who presented with a squamous cell carcinoma (SCC) in the mandible. Diagnosis was complicated because the clinical appearance was of a nonhealing extraction socket and the patient had a history of bisphosphonate therapy. An initial diagnosis of bisphosphonate-related osteonecrosis of the jaws was made, which delayed the commencement of appropriate treatment. This case highlights the importance of ruling out SCC in patients taking biological agents with unusual symptoms.

The epidemiology of cancers in human immunodeficiency virus infection and after organ transplantation

The authors provide an update on the association between immune deficiency and cancer risk in people with human immunodeficiency virus (HIV) and in solid organ transplant recipients. Over the past decade, it has become clear that a wider range of about 20 mostly infection-related cancers occur at increased rates in people with immune deficiency. The human herpes virus 8 (HHV8) and Epstein Barr Virus (EBV)-related cancers of Kaposi sarcoma (KS) and non-Hodgkin lymphoma (NHL) are most closely related to level of immune deficiency. Transplant recipients also have a greatly increased risk of squamous cell carcinoma (SCC) of the skin, related to direct carcinogenic effects of the pharmaceuticals used for immune suppression. For those three cancer types, the increased cancer risk is largely reversed when immune deficiency is decreased by treatment of HIV or by reduction of iatrogenic immune suppression. Other infection-related cancers also occur at increased rates, but it is not clear whether reduction of immune deficiency reduces cancer risk. Prostate and breast cancer do not occur at increased rates, providing strong evidence that these cancers are unlikely to be related to infection. Epidemiological and clinical trends in these two populations have led to substantial recent changes in cancer occurrence.

Mouth cancer awareness and beliefs among dental patients

OBJECTIVES

The aim of the present study was to assess the levels of awareness, knowledge about signs and risk factors of mouth (oral) cancer, and attitudes towards early diagnosis and treatment among dental outpatients.

MATERIAL AND METHODS

A total of 1,200 adult outpatients attending dental clinics at the University of Jordan Hospital for dental examination and treatment were randomly selected to participate in the study. An 18-item pretested close-ended questionnaire was used for the study. Descriptive statistics were generated and chi-square tests, t-tests, one-way analysis of variance (ANOVA), and Spearman's rho test were used to examine differences between groups.

RESULTS

Only 45.6% of the subjects had heard about oral cancer. Some 66.9% and 33.8%, respectively, were able to correctly identify tobacco and alcohol as risk factors. Some 24.1% had no knowledge about any signs of oral cancer. Male subjects, smokers, alcohol drinkers, older participants (>40 years), and participants with less than a university education were significantly less aware, and had much less knowledge, of the signs and risk factors of oral cancer (P<0.05).

CONCLUSION

Awareness about oral cancer among Jordanian dental outpatients is low. These dental patients, especially those in high-risk groups for mouth cancer and those of lower socio-economic status (SES), are less well informed about the signs and risk factors of oral cancer. Interventions to improve public knowledge about oral cancer and attitudes towards early diagnosis and treatment are urgently indicated.

Epidemiology of de novo malignancies after solid-organ transplantation: immunosuppression, infection and other risk factors

Organ transplantation is an increasingly used medical procedure for treating otherwise fatal end-stage organ diseases, and a large number of anti-rejection drugs have been developed to prolong long-term survival of both the individual and the transplanted organ. However, the prolonged use of immunosuppressive drugs is well known to increase the risk of opportunistic diseases, particularly infections and virus-related malignancies. Although transplant recipients experience a nearly twofold elevated risk for all types of de novo cancers, persistent infections with oncogenic viruses are associated with up to hundredfold increased risks. Women of the reproductive age are growing in number among the recipients of solid-organ transplants, but specific data on cancer outcomes are lacking. This article updates evidences linking iatrogenic immunosuppression, persistent infections with oncogenic viruses, other risk factors and post-transplant malignancies. Epidemiological aspects, tumourigenesis related to oncogenic viruses, clinical implications, as well as primary and secondary prevention issues are discussed to offer clinicians and researchers alike an update of an increasingly important topic.

Microencapsulation for the Therapeutic Delivery of Drugs, Live Mammalian and Bacterial Cells, and Other Biopharmaceutics: Current Status and Future Directions

Microencapsulation is a technology that has shown significant promise in biotherapeutics, and other applications. It has been proven useful in the immobilization of drugs, live mammalian and bacterial cells and other cells, and other biopharmaceutics molecules, as it can provide material structuration, protection of the enclosed product, and controlled release of the encapsulated contents, all of which can ensure efficient and safe therapeutic effects. This paper is a comprehensive review of microencapsulation and its latest developments in the field. It provides a comprehensive overview of the technology and primary goals of microencapsulation and discusses various processes and techniques involved in microencapsulation including physical, chemical, physicochemical, and other methods involved. It also summarizes the state-of-the-art successes of microencapsulation, specifically with regard to the encapsulation of microorganisms, mammalian cells, drugs, and other biopharmaceutics in various diseases. The limitations and future directions of microencapsulation technologies are also discussed.

Antihypertensive drugs and lip cancer in non-Hispanic whites

BACKGROUND

In screening pharmaceuticals for possible carcinogenic effects we noted an association between lip cancer risk and the photosensitizing antihypertensive drugs hydrochlorothiazide and nifedipine. In this study, we further characterized the risk of lip cancer associated with these and other commonly used antihypertensive drugs.

METHODS

In a comprehensive medical care program, we evaluated prescriptions dispensed and cancer occurrence from August 1, 1994, to February 29, 2008. We identified 712 patients with lip cancer (cases) and 22,904 comparison individuals (controls) matched for age, sex, and cohort year of entry in the susceptible group, non-Hispanic whites. We determined use, at least 2 years before diagnosis or control index date, of the commonly prescribed diuretics hydrochlorothiazide and hydrochlorothiazide combined with triamterene, the angiotensin-converting enzyme inhibitor lisinopril, the calcium channel blocker nifedipine, and the β-adrenergic blocker atenolol, the only nonphotosensitizer agent studied. We analyzed the use of each drug exclusively and regardless of use of the others, and focused on duration of use. Conditional logistic regression was used for analysis of matched case-control sets, with control for cigarette smoking.

RESULTS

At least a 5-year supply of a drug yielded the following odds ratios (95% CIs), respectively, compared with no use: hydrochlorothiazide, 4.22 (2.82-6.31); hydrochlorothiazide-triamterene, 2.82 (1.74-4.55); lisinopril, 1.42 (0.95-2.13); nifedipine, 2.50 (1.29-4.84); and atenolol, 1.93 (1.29-2.91). When the other drugs were excluded, the odds ratio for atenolol was reduced to 0.54 (0.07-4.08).

CONCLUSION

These data support an increased risk of lip cancer in non-Hispanic whites receiving treatment for hypertension with long-term use of photosensitizing drugs.

The risk of cancer is not increased in patients with multiple kidney transplantations

BACKGROUND

The aim of this study was to investigate whether the number of transplantations, as a marker of the graft rejection status of the patient, is associated with an increased risk of malignancies.

METHODS

In a cohort study, 1213 patients, receiving a kidney transplantation between 1966 and 1995 at the Leiden University Medical Center, were analyzed. All cutaneous squamous cell carcinoma and internal malignancies, which had developed between 1966 and 2007, were recorded. The influence of number of transplantations, age, sex and time on immunosuppression on the risk of squamous cell carcinoma and internal malignancies was investigated by time-dependent multivariate Cox's proportional hazard models.

RESULTS

Of the 1213 kidney transplant recipients, 319 received a second kidney, 78 a third; 13 of them a fourth and 4 of them a fifth transplantation. After adjustment for potentially confounding factors, including age, sex and years on immunosuppressive therapy we did not detect an increased risk of cancer in patients with multiple transplantations. On the contrary, patients with three or more transplantations had a 1.6-fold decreased risk of squamous cell carcinomas and a 3.6-fold decreased risk of internal malignancies.

CONCLUSION

We conclude that kidney transplant recipients with three or more transplantations do not have an increased risk of cutaneous squamous cell carcinoma and internal malignancies.

Incidence of malignancy after living kidney transplantation: a multicenter study from iran

Malignancy is a common complication after renal transplantation. However, limited data are available on post-transplant malignancy in living kidney transplantation. Therefore, we made a plan to evaluate the incidence and types of malignancies, association with the main risk factors and patient survival in a large population of living kidney transplantation. We conducted a large retrospective multicenter study on 12525 renal recipients, accounting for up to 59% of all kidney transplantation in Iran during 22 years follow up period. All information was collected from observation of individual notes or computerized records for transplant patients. Two hundred and sixty-six biopsy-proven malignancies were collected from 16 Transplant Centers in Iran; 26 different type of malignancy categorized in 5 groups were detected. The mean age of patients was 46.2±12.9 years, mean age at tumor diagnosis was 50.8±13.2 years and average time between transplantation and detection of malignancy was 50.0±48.4 months. Overall tumor incidence in recipients was 2%. Kaposis' sarcoma was the most common type of tumor. The overall mean survival time was 117.1 months (95% CI: 104.9-129.3). In multivariate analysis, the only independent risk factor associated with mortality was type of malignancy. This study revealed the lowest malignancy incidence in living unrelated kidney transplantation.

Orofacial diseases in solid organ and hematopoietic stem cell transplant recipients

OBJECTIVE

Solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients are at risk of several diseases, principally attributable to immunosuppression. This global overview of SOT/HSCT-associated orofacial diseases is aimed at providing a practical instrument for the oral healthcare management of SOT/HSCT recipients.

METHODS

Literature search was made through MEDLINE. The associations between orofacial diseases and SOT/HSCT were assessed using observational studies and case series and were classified into 'association', 'no association', and 'unclear association'.

RESULTS

Lip/oral cancers, drug-induced gingival overgrowth (DIGO), infections, including hairy leukoplakia and, less frequently, post-transplantation lymphoproliferative disorders (PTLDs) and oral lichenoid lesions of graft-versus-host disease (GVHD), were associated with SOT. Lip/oral cancers, GVHD, mucositis, DIGO, infections and, less frequently, PTLDs were associated with HSCT. Associations of orofacial granulomatosis-like lesions and oral mucosa-associated lymphoid tissue-type lymphoma with SOT, and of pyogenic granuloma and hairy leukoplakia with HSCT were unclear. Periodontal disease and dental caries were not associated with SOT/HSCT. For none of the local treatments was there a strong evidence of effectiveness.

CONCLUSIONS

Solid organ transplant/HSCT recipients are at risk of orofacial diseases. Adequate management of these patients alleviates local symptoms responsible for impaired eating, helps prevent systemic and lethal complications, and helps where dental healthcare has been neglected.

Immunohistochemical analysis of p53, APE1, hMSH2 and ERCC1 proteins in actinic cheilitis and lip squamous cell carcinoma

AIMS

This study has compared the tissue expression of the p53 tumour suppressor protein and DNA repair proteins APE1, hMSH2 and ERCC1 in normal, dysplastic and malignant lip epithelium.

METHODS AND RESULTS

Morphological analysis and immunohistochemistry were performed on archived specimens of normal lip mucosa (n=15), actinic cheilitis (AC) (n=30), and lip squamous cell carcinoma (LSCC) (n=27). AC samples were classified morphologically according to the severity of epithelial dysplasia and risk of malignant transformation. LSCC samples were morphologically staged according to WHO and invasive front grading (IFG) criteria. Differences between groups and morphological stages were determined by bivariate statistical analysis. Progressive increases in the percentage of epithelial cells expressing p53 and APE1 were associated with increases in morphological malignancy from normal lip mucosa to LSCC. There was also a significant reduction in epithelial cells expressing hMSH2 and ERCC1 proteins in the AC and LSCC groups. A higher percentage of malignant cells expressing APE1 was found in samples with an aggressive morphological IFG grade.

CONCLUSIONS

Our data showed that epithelial cells from premalignant to malignant lip disease exhibited changes in the expression of p53, APE1, hMSH2 and ERCC1 proteins; these molecular change might contribute to lip carcinogenesis.

Pediatric organ transplantation and risk of premalignant and malignant tumors in Sweden

Increased cancer risks are well documented in adult organ transplant recipients. However, the spectrum of malignancies and risk in the pediatric organ transplant population are less well described. We identified all solid organ transplanted patients aged <18 in Sweden between 1970-2007 (n = 536) in the National Patient Register and linked to the Cancer Register. Nationwide rates were used to calculate standardized incidence rate ratios and 95% CI estimating the association between transplant and cancer during maximum 36 years of follow-up. Nearly 7% of pediatric solid organ transplant recipients developed a premalignant or malignant tumor during follow-up. Transplantation was associated with an increased risk of any cancer (n = 24, SIR = 12.5, 95% CI: 8.0-18.6): non-Hodgkin lymphoma (NHL) (n = 13, SIR = 127, 95% CI: 68-217), renal cell (n = 3, SIR = 105, 95% CI: 22-307), vulva/vagina (n = 3, SIR = 665, 95% CI: 137-1934) and nonmelanoma skin cancers (n = 2, SIR = 64.7, 95% CI: 7.8-233.8). NHL typically appeared during childhood, while other tumors were diagnosed during adulthood. Apart from short-term attention toward the potential occurrence of NHL, our results suggest cancer surveillance into adulthood with special attention to skin, kidneys and the female genitalia.

Lip cancer: incidence, trends, histology and survival: 1970-2006

BACKGROUND

High levels of lip cancer have been reported among Israelis over the last four decades. Epidemiological descriptions and analyses for this region have not previously been presented.

OBJECTIVES

To establish the incidence, trends and histology of lip cancer and associated demographic variables in Israel over time.

METHODS

Data for 1970-2006 were derived from the Israel National Cancer Registry. Incidence and trends over time and analyses by lip site, sex, age, origin, histology and 5-year survival were studied.

RESULTS

Of 4337 new cases, most were found among men (61.4%), people aged over 53 years (75.5%), and those with lighter skin (62.6%). Lip cancer cases were 40 times more prevalent in the external than in the inner lip. The dominant tumour type was squamous cell carcinoma at the external lower lip and intraoral lip mucosa (predominantly in men) and basal cell carcinoma (originating from skin) at the external upper lip (predominantly in women). Minor salivary gland tumours, melanoma and metastases were also reported. Slight increases in the trend of upper lip cancer and decreases for lower lip cancer were reported.

CONCLUSIONS

Men, fair-skinned individuals and those over 53 years of age were at higher risk for lip cancer. A higher incidence of external lip cancer, compared with internal, may indicate a major role for sun exposure rather than smoking. The effect of public awareness campaigns as well as occupational changes, both related to sun exposure, should be studied carefully as potential factors in the changing incidence of lip tumours.

Effect of reduced immunosuppression after kidney transplant failure on risk of cancer: population based retrospective cohort study

OBJECTIVE

To compare cancer incidence in kidney transplant recipients during periods of transplant function (and immunosuppression) and after transplant failure (when immunosuppression is ceased or reduced). Design, setting, and participants Nationwide, population based retrospective cohort study of 8173 Australian kidney transplant recipients registered on the Australia and New Zealand Dialysis and Transplant Registry who first received a transplant during 1982-2003. Incident cancers were ascertained using linkage with national cancer registry records.

MAIN OUTCOME MEASURES

Cancer-specific standardised incidence ratios for periods of transplant function and for dialysis after transplant failure. Incidence was compared between periods using multivariate incidence rate ratios adjusted for current age, sex, and duration of transplantation.

RESULTS

All cases of Kaposi's sarcoma occurred during transplant function. Standardised incidence ratios were significantly elevated during transplant function, but not during dialysis after transplant failure, for non-Hodgkin's lymphoma, lip cancer, and melanoma. For each of these cancers, incidence was significantly lower during dialysis after transplant failure in multivariate analysis (incidence rate ratios 0.20 (95% CI 0.06 to 0.65) for non-Hodgkin's lymphoma, 0.04 (0.01 to 0.31) for lip cancer, and 0.16 (0.04 to 0.64) for melanoma). In contrast, standardised incidence ratios during dialysis after transplant failure remained significantly elevated for leukaemia and lung cancer, and cancers related to end stage kidney disease (kidney, urinary tract, and thyroid cancers), with thyroid cancer incidence significantly higher during dialysis after transplant failure (incidence rate ratio 6.77 (2.64 to 17.39)). There was no significant difference in incidence by transplant function for other cancers.

CONCLUSIONS

The effect of immunosuppression on cancer risk is rapidly reversible for some, but not all, cancer types. Risk reversal was mainly observed for cancers with a confirmed infectious cause. Risk of other cancers, especially those related to end stage kidney disease, remained significantly increased after reduction of immunosuppression.

Causes of oral cancer--an appraisal of controversies

Major risk factors for oral cancer are cigarette smoking and alcohol misuse. Among Asian populations, regular use of betel quid (with or without added tobacco) increases oral cancer risks. Dentists should be aware of some emerging risk factors for oral, and particularly oropharyngeal cancer such as the role of the human papillomavirus infection (HPV). Decreases in risk could be achieved by encouraging high fruit and vegetable consumption. Some controversies related to the aetiology of this disease also need clarification. The objective of this paper is to provide an opinion on these debated controversies.

Lip and oral mucosal lesions in 100 renal transplant recipients

BACKGROUND

Renal transplant recipients (RTRs) appear to be more susceptible to the development of oral mucosal disease and lip cancer as a result of graft-preserving immunosuppressive therapy. However, reports regarding these pathologies other than lip cancer are scarce and not studied in a detailed manner in this patient population.

OBJECTIVE

The aim of this study was to determine the prevalence rates and clinical features of lip lesions and oral mucosal lesions (OMLs) in RTRs.

METHODS

In all, 100 consecutive RTRs (21 female and 79 male) and 79 healthy age- and sex-matched control subjects (23 female and 56 male) were screened for all pathologic and pseudopathologic lip lesions and OMLs, with special interest on precancerous and cancerous lesions. Information about possible associated risk factors such as smoking and alcohol consumption was also obtained. Dermatologic investigation included clinical observation and direct microscopic examination, culture, and histopathological evaluation when indicated.

RESULTS

One or more lip lesions, OMLs, or both were noted in every participant of both groups. Fordyce spots on the lips was the most common lesion in the patient group (73%), followed by diffuse gingival enlargement (39%), fissured tongue (35%), and oral candidiasis (26%). The last 3 disorders were significantly more common in RTRs, whereas the frequency of Fordyce spots in patients and control subjects was similar. No actinic cheilitis, lip cancer, or oral malignancy was observed.

LIMITATIONS

This was a relatively small sample size for evaluating precancerous and cancerous lip lesions and OMLs, as they are less frequently observed than benign lesions.

CONCLUSIONS

Some of the benign OMLs (oral candidiasis and diffuse gingival enlargement) are increased in RTRs mainly as a result of the immunosuppressive therapy or drug side effects. Precancerous or cancerous lesions were not observed on the lips or the oral mucosa of our RTRs. This finding is in direct contrast with those of previous studies, yet this can be related to the limited sample size of this study regarding these lesions.

Cancer incidence and risk factors after solid organ transplantation

Iatrogenic immunosuppression is a unique setting for investigating immune-related mechanisms of carcinogenesis. Solid organ transplant recipients have a 3-fold excess risk of cancer relative to the age- and sex-matched general population. Population-based studies utilizing cancer registry records indicate that a wide range of cancers, mostly those with a viral etiology, occur at excess rates. To date, cancer risk has predominantly been examined in adult kidney transplant recipients in Western countries. It is yet to be established whether a similar incidence profile exists in the long-term for other solid organ, pediatric and non-Western transplant recipients. The cancer incidence profile before and after kidney transplantation strongly suggests a relatively minor contribution by both preexisting cancer risk factors and the conditions underlying end-stage kidney disease, and points to a causal role for immunosuppression. Within-cohort risk factor analyses have largely been performed on cohorts with voluntary cancer notification, and very few have incorporated biomarkers of the level of immunosuppression, the current receipt of immunosuppressive agents, or genetic risk factors. Because of their markedly high risk of certain cancers, findings from comprehensive studies in transplant recipients have the potential to raise new avenues for investigation into causal mechanisms and preventive measures against immune-related and infectious causes of cancer.

The pattern of excess cancer in dialysis and transplantation

BACKGROUND

After transplantation, cancer risk varies from no increase for several common cancers to a many-fold increase for a number of, chiefly virus-associated, cancers. The smaller excess of cancer in dialysis has been less well described, but two studies suggested that impaired immunity might be responsible.

METHODS

In a population-based cohort study of 28 855 patients who received renal replacement therapy (RRT), we categorized incident cancers as end-stage kidney disease (ESKD) related, immune deficiency related, not related to immune deficiency, or of uncertain status, according to whether they were, or were not, increased in published reports of cancer in ESKD prior to starting RRT, organ transplantation or human immunodeficiency virus infection. Standardized incidence ratios for, and excess burdens of, cancer were calculated for all persons normally resident in Australia starting treatment by dialysis or renal transplantation from 1982 to 2003.

RESULTS

The risk for ESKD-related cancers was increased 4-fold in dialysis and during transplant function. For immune deficiency-related cancers, the increase was 1.5 (95% CI 1.3-1.6) times in dialysis, and 5-fold after transplantation. ESKD- or immune deficiency-related cancers contributed to approximately 90% of the excess burden of cancer, 48% and 36%, respectively, in dialysis, and 10% and 78% after transplantation. The remaining excess malignancy was contributed by cancers whose relationship with ESKD and immune deficiency is not yet certain.

CONCLUSIONS

In RRT, the increase in cancer is restricted, largely if not wholly, to cancers with origins in ESKD or related to immune deficiency. For the former, the cancer risk is similar in dialysis and transplantation, but for immune deficiency-related cancers, the relative risk is much greater after transplantation.

Immunosuppression and other risk factors for early and late non-Hodgkin lymphoma after kidney transplantation

Non-Hodgkin lymphoma (NHL) incidence is greatly increased after kidney transplantation. NHL risk was investigated in a nationwide cohort of 8164 kidney transplant recipients registered on the Australia and New Zealand Dialysis and Transplant Registry. NHL diagnoses were ascertained using linkage with national cancer registry records. Multivariate Poisson regression was used to compute incidence rate ratios (IRRs) with 95% confidence intervals (CIs) comparing risk by transplant function, and risk factors for early (< 2 years) and late (>/= 2 years) NHL during the first transplantation. NHL occurred in 133 patients. Incidence was strikingly lower after transplant failure and cessation of immunosuppression than during transplant function (IRR, 0.25; 95% CI, 0.08-0.80; P = .019). Early NHL (n = 27) was associated with Epstein-Barr virus (EBV) seronegativity at transplantation (IRR, 4.66; 95% CI, 2.10-10.36, P < .001) and receipt of T cell-depleting antibodies (IRR, 2.39; 95% CI, 1.08-5.30; P = .031). Late NHL (n = 79) was associated with increasing year of age (IRR, 1.02; 95% CI, 1.01-1.04; P = .006), increasing time since transplantation (P < .001), and current use of calcineurin inhibitors (IRR, 3.13; 95% CI, 1.53-6.39; P = .002). These findings support 2 mechanisms of lymphomagenesis, one predominantly of primary EBV infection in the context of intense immunosuppression, and another of dysregulated lymphoid proliferation in a prolonged immunosuppressed state.