Pathogenesis of nonmelanoma skin cancers in organ transplant recipients

Metastasis of skin squamous cell carcinoma in kidney transplant recipients

Cutaneous squamous cell carcinoma (cSCC) is the most common skin malignancy in kidney transplant recipients (KTRs) as a result of immunosuppression. A worldwide increase in kidney transplantation justifies the determination of prognostic biomarkers by collecting detailed patient data on metastasis development. This study aims to characterize the clinical, epidemiological, and histopathological profiles of KTRs who developed metastasis of cSCC. We conducted a retrospective single-center study on 18 KTRs and 21 immunocompetent patients (ICs) with metastatic cSCC, using data from 2004 to 2021. ICs were older (median age 70.5 years) than KTRs (median age: 59.5 years). Both groups were predominantly male with Fitzpatrick skin phototype I/II. The primary tumor appeared around 83.5 months post-transplant, usually in sun-exposed areas (61.1%), though some non-exposed areas in ICs (23.8%) contradicted literature findings. KTRs took longer to develop metastasis (median: 11.0 months) compared to ICs (median: 5.5 months). The mean size of the primary tumor was smaller in KTRs (2.50 cm2) compared to ICs (4.55 cm2). The main lymph node chain affected by metastasis was parotid lymph nodes in KTRs (27.8%) and cervical/axillar lymph nodes in ICs (both 19.0%). Both groups exhibited similar primary tumor grades and metastasis evolution, but KTRs had a higher prevalence of lymphovascular invasion. Metastasis of cSCC was more common in males with low skin phototype, in KTRs, particularly on the head and neck. The study suggests a possible link between lymphovascular invasion and metastasis development in KTRs.

Cemiplimab for Kidney Transplant Recipients With Advanced Cutaneous Squamous Cell Carcinoma

PURPOSE

Cemiplimab is approved for treating locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC). Solid organ transplant recipients have been excluded from immunotherapy trials, given concern for allograft rejection despite their increased risk of skin cancers. Chronic immunosuppression is necessary to prevent organ rejection but may attenuate antitumor response with PD-1 inhibitors.

METHODS

We report a phase I study of cemiplimab for kidney transplant recipients (KTRs) with advanced CSCC. After cross-taper to a mammalian target of rapamycin (mTOR) inhibitor and pulsed dose corticosteroids (prednisone 40 mg once daily, the day before and on days 1-3 of each cycle, followed by 20 mg once daily on days 4-6, then 10 mg once daily until the day before each subsequent cycle), patients received cemiplimab 350 mg intravenously once every 3 weeks for up to 2 years and were assessed for response every 8 weeks. The primary end point was the rate of kidney rejection, with key secondary end points including rate and duration of response, and survival.

RESULTS

Twelve patients were treated. No kidney rejection or loss was observed. A response to cemiplimab was observed in five of 11 evaluable patients (46%; 90% CI, 22 to 73), including two with durable responses beyond a year. Median follow-up was 6.8 months (range, 0.7-29.8). Treatment-related grade 3 or greater adverse events occurred in five patients (42%), including diarrhea, infection, and metabolic disturbances. One patient died of angioedema and anaphylaxis attributed to mTOR inhibitor cross-taper.

CONCLUSION

mTOR inhibitor and corticosteroids represent a favorable immunosuppressive regimen for KTRs with advanced CSCC receiving immunotherapy. This combination resulted in durable antitumor responses with no kidney rejection events (funded by Regeneron Pharmaceuticals [ClinicalTrials.gov identifier: NCT04339062]).

An update on clinical trials for chemoprevention of human skin cancer

The pathophysiology of skin cancer is complex, with multiple factors contributing to its development. The proactive treatment of skin cancer has been investigated in the form of chemoprevention of cutaneous malignancies in clinical trials. Chemoprevention is the use of natural or pharmacologic agents that prevent or reverse skin cancer development. Multiple trials have arisen over the past decades to explore the efficacy of specific agents to halt the progression of UV radiation damage. This comprehensive review article aims to assess clinical trials performed with chemopreventive agents for melanoma and nonmelanoma skin cancers. The following compounds were most often used in these trials: nicotinamide, retinoids, polyphenolic antioxidants, COX-2 selective inhibitors, non-steroidal anti-inflammatory drugs, difluoromethylornithine, and 5-fluorouracil. Many agents show promise in their ability to prevent nonmelanoma skin cancer formation, with few melanoma trials demonstrating efficacy. The chemoprevention efforts aimed at skin cancer are complex; current and future trials will be instrumental in identifying therapeutic agents that pose efficacy in halting cancer development and assessing whether long-term administration is tolerable.

CYP11A1‑derived vitamin D hydroxyderivatives as candidates for therapy of basal and squamous cell carcinomas

Hydroxyderivatives of vitamin D3, including classical 1,25(OH)2D3 and novel CYP11A1‑derived hydroxyderivatives, exert their biological activity by acting as agonists on the vitamin D receptor (VDR) and inverse agonists on retinoid‑related orphan receptors (ROR)α and γ. The anticancer activities of CYP11A1‑derived hydroxyderivatives were tested using cell biology, tumor biology and molecular biology methods in human A431 and SCC13 squamous (SCC)‑ and murine ASZ001 basal (BCC)‑cell carcinomas, in comparison with classical 1,25(OH)2D3. Vitamin D3‑hydroxyderivatives with or without a C1α(OH) inhibited cell proliferation in a dose‑dependent manner. While all the compounds tested had similar effects on spheroid formation by A431 and SCC13 cells, those with a C1α(OH) group were more potent in inhibiting colony and spheroid formation in the BCC line. Potent anti‑tumorigenic activity against the BCC line was exerted by 1,25(OH)2D3, 1,20(OH)2D3, 1,20,23(OH)3D3, 1,20,24(OH)3D3, 1,20,25(OH)3D3 and 1,20,26(OH)3D3, with smaller effects seen for 25(OH)D3, 20(OH)D3 and 20,23(OH)2D3. 1,25(OH)2D3, 1,20(OH)2D3 and 20(OH)D3 inhibited the expression of GLI1 and β‑catenin in ASZ001 cells. In A431 cells, these compounds also decreased the expression of GLI1 and stimulated involucrin expression. VDR, RORγ, RORα and CYP27B1 were detected in A431, SCC13 and ASZ001 lines, however, with different expression patterns. Immunohistochemistry performed on human skin with SCC and BCC showed nuclear expression of all three of these receptors, as well as megalin (transmembrane receptor for vitamin D‑binding protein), the level of which was dependent on the type of cancer and antigen tested in comparison with normal epidermis. Classical and CYP11A1‑derived vitamin D3‑derivatives exhibited anticancer‑activities on skin cancer cell lines and inhibited GLI1 and β‑catenin signaling in a manner that was dependent on the position of hydroxyl groups. The observed expression of VDR, RORγ, RORα and megalin in human SCC and BCC suggested that they might provide targets for endogenously produced or exogenously applied vitamin D hydroxyderivatives and provide excellent candidates for anti‑cancer therapy.

The significance of CYP11A1 expression in skin physiology and pathology

CYP11A1, a member of the cytochrome P450 family, plays several key roles in the human body. It catalyzes the first and rate-limiting step in steroidogenesis, converting cholesterol to pregnenolone. Aside from the classical steroidogenic tissues such as the adrenals, gonads and placenta, CYP11A1 has also been found in the brain, gastrointestinal tract, immune systems, and finally the skin. CYP11A1 activity in the skin is regulated predominately by StAR protein and hence cholesterol levels in the mitochondria. However, UVB, UVC, CRH, ACTH, cAMP, and cytokines IL-1, IL-6 and TNFα can also regulate its expression and activity. Indeed, CYP11A1 plays several critical roles in the skin through its initiation of local steroidogenesis and specific metabolism of vitamin D, lumisterol, and 7-dehydrocholesterol. Products of these pathways regulate the protective barrier and skin immune functions in a context-dependent fashion through interactions with a number of receptors. Disturbances in CYP11A1 activity can lead to skin pathology.

Cutaneous Head and Neck Cancers in the High-Risk Immunosuppressed Population

The immunosuppressed (IS) population encompasses a diverse cohort of patients to include iatrogenically immunocompromised organ transplant recipients as well as patients with chronic lymphoid malignancies, human immunodeficiency virus/acquired immunodeficiency syndrome, and autoimmune disorders. Cutaneous cancers in this high-risk patient group are clinically distinct from the general immunocompetent population, showing aggressive behavior with associated poor outcomes. This article reviews the pathogenesis, epidemiology, incidence, prognosis, and special considerations required in managing cutaneous cancers in the IS patient population.

Solid organ transplantation worsens the prognosis of patients with cutaneous squamous cell carcinoma of the head and neck region-Comparison between solid organ transplant recipients and immunocompetent patients

BACKGROUND

Cutaneous squamous cell carcinoma of the head and neck (CSCC-HN) appears to behave more aggressively in immunosuppressed patients. We aimed to investigate this hypothesis by comparing solid organ transplant recipients (SOTR) with CSCC-HN to immunocompetent patients.

METHODS

A retrospective comparative study was conducted for SOTR and immunocompetent patients who were treated for CSCC-HN.

RESULTS

A total of 177 SOTR and 157 immunocompetent patients with CSCC-HN were included. Lymph node metastases were more common in the SOTR group (9% vs 3%), and distant metastases occurred only in SOTR (3% of patients). SOTR had a higher rate of recurrences (19% vs 10%), which were mostly regional (7%) and distant (3%). The 2-year disease-specific survival of SOTR was lower (93% vs 100%).

CONCLUSIONS

SOTR with CSCC-HN has significantly worse outcomes compared to immunocompetent patients. Solid-organ transplantation should be regarded as a negative prognostic factor in patients with CSCC-HN.

5'-Cap‒Dependent Translation as a Potent Therapeutic Target for Lethal Human Squamous Cell Carcinoma

Skin squamous cell carcinomas (SCCs) are a major cause of death in patients who have undergone or will undergo organ transplantation. Moreover, these neoplasms cause significant disease and economic burden and diminish patients' life quality. However, no effective treatment or intervention strategies are available. In this study, we investigated the pathologic role of 5'-cap translation, which is regulated by the formation of a ternary initiation factor complex involving eIF4E, eIF4G, and eIF4A1. We detected increased expression of phosphorylated eIF4E, eIF4G, and eIF4A1 in human and murine skin SCCs. The increase in these ternary initiation factor complex proteins was associated with enhanced eIF4E translation targets cyclin D1 and c-Myc. Conversely, small interfering RNA-mediated depletion of eIF4E in human SCC cells (A431 and SCC-13) reduced eIF4G and proteins that regulate the cell cycle and proliferation. Notably, inhibition of Raf/MAPK/extracellular signal-regulated kinase signaling decreased eIF4E and phosphorylated eIF4E accumulation and significantly diminished cell-cycle gene expression and tumor volume of A431-derived xenograft tumors. Furthermore, disrupting the eIF4E with an allosteric inhibitor of eIF4E and eIF4G binding, 4EGI-1, decreased the eIF4E/eIF4G expression and reduced the proliferation. Finally, combined inhibition of the Raf/MAPK/extracellular signal-regulated kinase axis and eIF4E impaired 5'-cap‒dependent translation and abrogated tumor cell proliferation. These data demonstrate that 5'-cap‒dependent translation is a potential therapeutic target for abrogating lethal skin SCCs in patients who have undergone or will undergo organ transplantation.

Photocarcinogenesis

Purpose of Review

Skin cancers account for more than 40% of all cancers in the USA and continue to rise in incidence. It is prudent to understand the current burden and pathogenesis of photocarcinogenesis and preventive measures.

Recent Findings

Insights into recently discovered mechanisms have paved way for potential targets for prevention and therapeutics. Nicotinamide has shown promising results as an oral chemopreventive agent. UVB affects the DHODH pathway of pyrimidine synthesis via STAT 3. DHODH inhibition by leflunomide may be a potential targeted chemoprevention strategy. A photolyase containing sunscreen, which repairs UV-damaged DNA, effectively reduced new precancerous lesions. Several antioxidants and anti-inflammatory agents including many phytochemicals ameliorate the process of photocarcinogenesis in preclinical and clinical studies, e.g., green tea polyphenols, Polypodium leucotomos extract, and Timosaponin A III. Diet can potentially affect skin cancer risk by its ability to modify oxidative stress and cell signaling pathways.

Summary

Photocarcinogenesis is a multi-step process. An in-depth understanding is instrumental in development of novel agents for prevention and treatment of skin cancers.

The Role of Classical and Novel Forms of Vitamin D in the Pathogenesis and Progression of Nonmelanoma Skin Cancers

Nonmelanoma skin cancers including basal and squamous cell carcinomas (SCC and BCC) represent a significant clinical problem due to their relatively high incidence, imposing an economic burden to healthcare systems around the world. It is accepted that ultraviolet radiation (UVR: λ = 290-400 nm) plays a crucial role in the initiation and promotion of BCC and SCC with UVB (λ = 290-320 nm) having a central role in this process. On the other hand, UVB is required for vitamin D3 (D3) production in the skin, which supplies >90% of the body's requirement for this prohormone. Prolonged exposure to UVB can also generate tachysterol and lumisterol. Vitamin D3 itself and its canonical (1,25(OH)2D3) and noncanonical (CYP11A1-intitated) D3 hydroxyderivatives show photoprotective functions in the skin. These include regulation of keratinocyte proliferation and differentiation, induction of anti-oxidative responses, inhibition of DNA damage and induction of DNA repair mechanisms, and anti-inflammatory activities. Studies in animals have demonstrated that D3 hydroxyderivatives can attenuate UVB or chemically induced epidermal cancerogenesis and inhibit growth of SCC and BCC. Genomic and non-genomic mechanisms of action have been suggested. In addition, vitamin D3 itself inhibits hedgehog signaling pathways which have been implicated in many cancers. Silencing of the vitamin D receptor leads to increased propensity to develop UVB or chemically induced epidermal cancers. Other targets for vitamin D compounds include 1,25D3-MARRS, retinoic orphan receptors α and γ, aryl hydrocarbon receptor, and Wnt signaling. Most recently, photoprotective effects of lumisterol hydroxyderivatives have been identified. Clinical trials demonstrated a beneficial role of vitamin D compounds in the treatment of actinic keratosis. In summary, recent advances in vitamin D biology and pharmacology open new exciting opportunities in chemoprevention and treatment of skin cancers.

Patched1 haploinsufficiency severely impacts intermediary metabolism in the skin of Ptch1+/-/ODC transgenic mice

The study of dominantly heritable cancers has provided insights about tumor development. Gorlin syndrome (GS) is an autosomal dominant disorder wherein affected individuals develop multiple basal cell carcinomas (BCCs) of the skin. We developed a murine model of Ptch1 haploinsufficiency on an ornithine decarboxylase (ODC) transgenic background (Ptch1^+/−/ODC^t/C57BL/6) that is more sensitive to BCCs growth as compared with Ptch1^+/+/ODC^t/C57BL/6 littermates. Ptch1^+/−/ODC^t/C57BL/6 mice show an altered metabolic landscape in the phenotypically normal skin, including restricted glucose availability, restricted ribose/deoxyribose flow and NADPH production, an accumulation of α-ketoglutarate, aconitate, and citrate that is associated with reversal of the tricarboxylic acid cycle, coupled with increased ketogenic/lipogenic activity via acetyl-CoA, 3-hydroybutyrate, and cholesterol metabolites. Also apparent was an increased content/acetylation of amino-acids, glutamine and glutamate, in particular. Accordingly, metabolic alterations due to a single copy loss of Ptch1 in Ptch1^+/−/ODC^t/C57BL/6 heterozygous mice may provide insights about the cancer prone phenotype of BCCs in GS patients, including biomarkers/targets for early intervention.

HLA alleles in renal transplant recipients with nonmelanoma skin cancer in southeastern Brazil

BACKGROUND

Renal transplant recipients are submitted to immunosuppression to avoid graft rejection, which makes them susceptible to various conditions. Furthermore, these individuals present malignant tumors more frequently than the general population, including nonmelanoma skin cancer. The individual genetic basis that acts in the pathogenesis of cutaneous cancer may present a protection or susceptibility factor for disease development. One of these factors is the HLA complex.

OBJECTIVE

To investigate HLA alleles association to the occurrence of nonmelanoma skin cancer in renal transplant recipients from São Paulo State.

METHODS

A total of 213 patients (93 renal transplant recipients with nonmelanoma skin cancer and 120 renal transplant recipients without nonmelanoma skin cancer) were evaluated by retrospective and cross-sectional study. Epidemiological, clinical and HLA typing data were found in databases. HLA class I (A, B) and class II (DR) alleles were compared to establish their association with nonmelanoma skin cancer.

RESULTS

Comparing renal transplant recipients with and without nonmelanoma skin cancer, the HLA-B*13 allele was associated with higher risk of developing nonmelanoma skin cancer while B*45 and B*50 alleles were associated with protection.

STUDY LIMITATIONS

The HLA A, B and DR alleles identification for the kidney transplantation routine is done by low and medium resolution techniques that do not allow discrimination of specific alleles.

CONCLUSION

The involvement of HLA alleles in nonmelanoma skin cancer in renal transplant recipients was confirmed in this study. Renal transplant recipients with HLA-B*13 showed higher risk for developing a skin cancer (OR= 7.29) and should be monitored for a long period of time after transplantation.

Temporal Trends of De Novo Malignancy Development After Heart Transplantation

BACKGROUND

Malignancy is a concern in cardiac transplant recipients, but the temporal trends of de novo malignancy development are unknown.

OBJECTIVES

The goal of this study was to describe the temporal trends of the incidence, types, and predictors of de novo malignancy in cardiac transplant recipients.

METHODS

The authors analyzed the temporal trends of post-transplant incidence, types, and predictors of malignancy using 17,587 primary adult heart-only transplant recipients from the International Society for Heart and Lung Transplantation registry. The main study outcomes included the incidence of, types of, and time to de novo malignancy.

RESULTS

The risk of any de novo solid malignancy between years 1 and 5 after transplantation was 10.7%. The cumulative incidence by malignancy type was: skin cancer (7.0%), non-skin solid cancer (4.0%), and lymphoproliferative disorders (0.9%). There was no temporal difference in the time to development according to malignancy type. However, the cumulative incidence of de novo solid malignancy increased from 2000 to 2005 vs. 2006 to 2011 (10.0% vs. 12.4%; p < 0.0001). Survival in patients after de novo malignancy was markedly lower than in patients without malignancy (p < 0.0001). Older recipients and patients who underwent transplantation in the recent era had a higher risk of de novo malignancy.

CONCLUSIONS

More than 10% of adult heart transplant recipients developed de novo malignancy between years 1 and 5 after transplantation, and this outcome was associated with increased mortality. The incidence of post-transplant de novo solid malignancy increased temporally, with the largest increase in skin cancer. Individualized immunosuppression strategies and enhanced cancer screening should be studied to determine whether they can reduce the adverse outcomes of post-transplantation malignancy.

Non-invasive analysis of actinic keratosis using a cold stimulation and near-infrared spectroscopy

Non-melanoma skin cancers are the most common tumor in the Caucasian population, and include actinic keratosis (AK), which is considered an early form of in-situ squamous cell carcinoma (SCC). Currently the only way to monitor lesion progression (i.e., from AK to invasive SCC) is through an invasive bioptic procedure. Near-infrared spectroscopy (NIRS) is a non-invasive technique that studies haemoglobin (oxygenated haemoglobin, O2Hb, and deoxygenated haemoglobin, HHb) relative concentration variations. The objective of this study is to evaluate if AKs present a different vascular response when compared to healthy skin using time and frequency parameters extracted from the NIRS signals. The NIRS signals were acquired on the AKs and a healthy skin area of patients (n=53), with the same acquisition protocol: baseline signals (1.5 min), application of ice pack near lesion (1.5 min), removal of ice pack and acquisition of vascular recovery (1.5 min). We calculated 18 features to evaluate if the vascular response was different in the two cases (i.e., healthy skin and AK lesions). By applying the multivariate analysis of variance (MANOVA), a statistically significant difference is found in the O2Hb and HHb after the stimulus application. This shows how the NIRS technique can give important vascular information that could help the diagnosis of a lesion and the evaluation of its progression. Overall, the obtained results encourage us to look further into the study of the skin lesions and their progression with NIRS signals.

Cutaneous Complications in Recipients of Lung Transplants: A Pictorial Review

Lung transplant is now an established modality for a broad spectrum of end-stage pulmonary diseases. According to the International Society for Heart and Lung Transplantation Registry, more than 50,000 lung transplants have been performed worldwide, with nearly 11,000 recipients of lung transplants alive in the United States. With the increasing use of lung transplant, pulmonologists must be cognizant of the common as well as the unique posttransplant dermatologic complications. Immunosuppression, infections, and a variety of medications and environmental exposures can contribute to these complications. This review aims to provide representative pictures and describe the pathogenesis, epidemiologic characteristics, and clinical manifestations of dermatologic complications encountered among recipients of lung transplants.

Ruxolitinib inhibits cyclosporine-induced proliferation of cutaneous squamous cell carcinoma

Organ transplant recipients (OTRs) on cyclosporine A (CSA) are prone to catastrophic cutaneous squamous cell carcinoma (SCC). Allograft-sparing, cancer-targeting systemic treatments are unavailable. We have shown increased risk for catastrophic SCC in OTRs via CSA-mediated induction of IL-22. Herein, we found that CSA drives SCC proliferation and tumor growth through IL-22 and JAK/STAT pathway induction. We in turn inhibited SCC growth with an FDA-approved JAK1/2 inhibitor, ruxolitinib. In human SCC cells, the greatest proliferative response to IL-22 and CSA treatment occurred in nonmetastasizing lines. IL-22 treatment upregulated JAK1 and STAT1/3 in A431 SCC cells. JAK/STAT pathway genes were highly expressed in tumors from a cohort of CSA-exposed OTRs and in SCC with high risk for metastasis. Compared with immunocompetent SCC, genes associated with innate immunity, response to DNA damage, and p53 regulation were differentially expressed in SCC from OTRs. In nude mice engrafted with human A431 cells, IL-22 and CSA treatment increased tumor growth and upregulated IL-22 receptor, JAK1, and STAT1/3 expression. Ruxolitinib treatment significantly reduced tumor volume and reversed the accelerated tumor growth. CSA and IL-22 exacerbate aggressive behavior in SCC. Targeting the IL-22 axis via selective JAK/STAT inhibition may reduce the progression of aggressive SCC in OTRs, without compromising immunosuppression.

Skin Cancers in Organ Transplant Recipients

Long-term utilization of immunosuppression in organ transplant recipients (OTRs) leads to decreased immune-mediated tumor surveillance and development of malignant tumors. A delicate balance needs to be maintained in the intensity of immunosuppression to keep the risk of malignancy low without jeopardizing life-saving graft function. OTRs are prone to developing skin cancers that exhibit unique epidemiologic, pathophysiologic, and prognostic characteristics. In this review, we discuss the most commonly reported skin cancers in OTRs: squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Kaposi sarcoma, Merkel cell carcinoma, and malignant melanoma (MM). Tumors in this high-risk population are aggressive and may respond poorly to standard therapies; however, new targeted therapies are promising. Checkpoint inhibitor antibodies have been used for treatment of cutaneous SCC, Merkel cell carcinoma, and MM; epidermal growth factor receptor inhibitors have been used for cutaneous SCC; hedgehog pathway inhibitors have been used for BCC; and BRAF and MEK inhibitors are being used increasingly in the management of MM. Guidelines for dermatologic screening are variable and primarily based on expert opinion. Prospective evidence-based trials by multidisciplinary groups are needed to better define surveillance schedules for pre- and posttransplant cutaneous malignancies.

Molecular signaling cascades involved in nonmelanoma skin carcinogenesis

Nonmelanoma skin cancer (NMSC) is the most common cancer worldwide and the incidence continues to rise, in part due to increasing numbers in high-risk groups such as organ transplant recipients and those taking photosensitizing medications. The most significant risk factor for NMSC is ultraviolet radiation (UVR) from sunlight, specifically UVB, which is the leading cause of DNA damage, photoaging, and malignant transformation in the skin. Activation of apoptosis following UVR exposure allows the elimination of irreversibly damaged cells that may harbor oncogenic mutations. However, UVR also activates signaling cascades that promote the survival of these potentially cancerous cells, resulting in tumor initiation. Thus, the UVR-induced stress response in the skin is multifaceted and requires coordinated activation of numerous pathways controlling DNA damage repair, inflammation, and kinase-mediated signal transduction that lead to either cell survival or cell death. This review focuses on the central signaling mechanisms that respond to UVR and the subsequent cellular changes. Given the prevalence of NMSC and the resulting health care burden, many of these pathways provide promising targets for continued study aimed at both chemoprevention and chemotherapy.

Non-melanoma skin cancer in Portuguese kidney transplant recipients - incidence and risk factors

BACKGROUND

Cancer is currently among the three leading causes of death after solid organ transplantation and its incidence is increasing. Non-melanoma skin cancer - squamous cell carcinoma and basal cell carcinoma - is the most common malignancy found in kidney transplant recipients (KTRs). The incidence of non-melanoma skin cancer in KTRs has not been extensively studied in Portugal.

OBJECTIVES

To determine the incidence of non-melanoma skin cancer in KTRs from the largest Portuguese kidney transplant unit; and to study risk factors for non-melanoma skin cancer.

METHODS

Retrospective analysis of clinical records of KTRs referred for the first time for a dermatology consultation between 2004 and 2013. A case-control study was performed on KTRs with and without non-melanoma skin cancer.

RESULTS

We included 288 KTRs with a median age at transplantation of 47 years, a male gender predominance (66%) and a median transplant duration of 3.67 years. One fourth (n=71) of KTRs developed 131 non-melanoma skin cancers, including 69 (53%) squamous cell carcinomas and 62 (47%) basal cell carcinomas (ratio squamous cell carcinoma: basal cell carcinoma 1.11), with a mean of 1.85 neoplasms per patient. Forty percent of invasive squamous cell carcinomas involved at least two clinical or histological high-risk features. The following factors were associated with a higher risk of non-melanoma skin cancer: an older age at transplantation and at the first consultation, a longer transplant duration and the presence of actinic keratosis. KTRs treated with azathioprine were 2.85 times more likely to develop non-melanoma skin cancer (p=0.01).

CONCLUSION

Non-melanoma skin cancer was a common reason for dermatology consultation in Portuguese KTRs. It is imperative for KTRs to have access to specialized dermatology consultation for early referral and treatment of skin malignancies.

Skin cancer screening: recommendations for data-driven screening guidelines and a review of the US Preventive Services Task Force controversy

Melanoma is usually apparent on the skin and readily detected by trained medical providers using a routine total body skin examination, yet this malignancy is responsible for the majority of skin cancer-related deaths. Currently, there is no national consensus on skin cancer screening in the USA, but dermatologists and primary care providers are routinely confronted with making the decision about when to recommend total body skin examinations and at what interval. The objectives of this paper are: to propose rational, risk-based, data-driven guidelines commensurate with the US Preventive Services Task Force screening guidelines for other disorders; to compare our proposed guidelines to recommendations made by other national and international organizations; and to review the US Preventive Services Task Force's 2016 Draft Recommendation Statement on skin cancer screening.

Keratinocyte Carcinoma as a Marker of a High Cancer-Risk Phenotype

Keratinocyte carcinoma (KC) (also referred to as nonmelanoma skin cancer) is by far the most common form of human cancer. A personal history of KC is well established to be associated with increased risk of recurrent KC and malignant melanoma, a less common yet more fatal form of skin cancer. More surprising is that a substantial body of epidemiologic evidence now indicates that a personal history of KC is significantly associated with an overall elevated risk of noncutaneous malignancies. This association is not limited to one or a few types of cancer but applies across many different types of malignancy. This association has been consistently observed in prospective studies across genders for both major histologic types of KC, basal cell carcinoma and squamous cell carcinoma. The risk of other cancers has been even stronger in those with younger compared with older age of onset of KC. A robust body of evidence lends support to the notion that KC may be a marker of a high cancer-risk phenotype. The underlying mechanisms for this association remain to be elucidated, but the cross-cutting nature of this association across numerous malignancies suggests that research to uncover these mechanisms is a promising line of inquiry that could potentially yield valuable insight into human carcinogenesis.

Skin Cancer Risk Is Modified by KIR/HLA Interactions That Influence the Activation of Natural Killer Immune Cells

Natural killer (NK)-cell phenotype is partially mediated through binding of killer-cell immunoglobulin-like receptors (KIR) with HLA class I ligands. The KIR gene family is highly polymorphic and not well captured by standard genome-wide association study approaches. Here, we tested the hypothesis that variations in KIR gene content combined with HLA class I ligand status is associated with keratinocyte skin cancers using a population-based study of basal cell carcinoma (BCC) and squamous cell carcinomas (SCC). We conducted an interaction analysis of KIR gene content variation and HLA-B (Bw4 vs. Bw6) and HLA-C (C1 vs. C2). KIR centromeric B haplotype was associated with significant risk of multiple BCC tumors (OR, 2.39; 95% confidence interval, 1.10-5.21), and there was a significant interaction between HLA-C and the activating gene KIR2DS3 for BCC (Pinteraction = 0.005). Furthermore, there was significant interaction between HLA-B and telomeric KIR B haplotype (containing the activating genes KIR3DS1 and KIR2DS1) as well as HLA-B and the activating KIR gene KIR2DS5 (Pinteraction 0.001 and 0.012, respectively). Similar but greatly attenuated associations were observed for SCC. Moreover, previous in vitro models demonstrated that p53 is required for upregulation of NK ligands, and accordingly, we observed there was a strong association between the KIR B haplotype and p53 alteration in BCC tumors, with a higher likelihood that KIR B carriers harbor abnormal p53 (P < 0.004). Taken together, our data suggest that functional interactions between KIR and HLA modify risks of BCC and SCC and that KIR encoded by the B genes provides selective pressure for altered p53 in BCC tumors.

Skin Carcinogenesis Studies Using Mouse Models with Altered Polyamines

Nonmelanoma skin cancer (NMSC) is a major health concern worldwide. With increasing numbers in high-risk groups such as organ transplant recipients and patients taking photosensitizing medications, the incidence of NMSC continues to rise. Mouse models of NMSC allow us to better understand the molecular signaling cascades involved in skin tumor development in order to identify novel therapeutic strategies. Here we review the models designed to determine the role of the polyamines in NMSC development and maintenance. Elevated polyamines are absolutely required for tumor growth, and dysregulation of their biosynthetic and catabolic enzymes has been observed in NMSC. Studies using mice with genetic alterations in epidermal polyamines suggest that they play key roles in tumor promotion and epithelial cell survival pathways, and recent clinical trials indicate that pharmacological inhibitors of polyamine metabolism show promise in individuals at high risk for NMSC.

Non-melanoma skin cancer in renal transplant recipients: a study in a Brazilian reference center

BACKGROUND

Non-melanoma skin cancer (NMSC) after kidney transplantation is common and can result in significant morbidity and mortality. Their incidence and risk factors in renal transplant recipients (RTRs) vary depending on geographic location and there is a scarcity of literature describing the features of NMSC in Brazil.

METHODS

NMSC data were retrospectively reviewed in charts of RTRs at the Clementino Fraga Filho University Hospital from January 2004 to December 2005, with the objectives of: 1) evaluating the occurrence of NMSC in RTRs transplanted between 2004 and 2005 at a reference center in Brazil; 2) verifying the frequency of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in these patients according to sex, race, age, and tumor site; and 3) determining the time between transplantation and neoplasia.

RESULTS

We found 202 RTRs, with 165 suitable for the study. There were 19 NMSC in eleven patients (6.67%), at a mean time of 37.7 months after transplantation. The mean follow-up time was 72.7 months. The ratio of SCC:BCC was 1.1:1. White race and age ≥40 years were associated with a higher incidence of NMSC and they appeared predominantly in sun-exposed sites.

CONCLUSION

Regular dermatological follow-up of RTRs can help to make earlier diagnoses, resulting in better quality of life and lower morbidity and mortality.

Epidemiology and clinical evolution of non-melanoma skin cancer in renal transplant recipients: a single-center experience in São Paulo, Brazil

BACKGROUND

Non-melanoma skin cancer (NMSC) is very common among renal transplant recipients (RTRs) as a result of the immunosuppressed status of these patients and other factors. Few studies have examined the clinical characteristics and evolution of NMSC in RTRs in tropical countries.

OBJECTIVES

The aim of this study was to characterize the epidemiology and clinical evolution of NMSC in RTRs.

METHODS

We conducted a retrospective study including 68 RTRs with NMSC diagnosed from July 2004 to December 2009 with a minimum follow-up of three years. We analyzed demographic and transplant- and NMSC-related data.

RESULTS

The mean age of patients at the first diagnosis of NMSC was 51 years (range: 29-71 years). Most first diagnoses occurred within nine years post-transplant. The majority of patients (n = 48) had Fitzpatrick skin phototype II, although NMSC was also observed in those with skin phototypes III and IV. Forty-six (67.6%) RTRs had received a kidney from a living donor. Fifty-five (80.9%) RTRs had received cytotoxic immunosuppressives, 51 (75.0%) had received calcineurin inhibitors, and two (2.9%) had received mTOR inhibitors. Most of the RTRs developed about eight NMSC lesions, but up to 25 NMSC lesions were diagnosed in one patient. Most lesions (67.6%) were located on sun-exposed areas. Squamous cell carcinoma (SCC) represented the predominant tumor type, accounting for 70.6% of all tumors, whereas basal cell carcinoma accounted for 29.4% of all tumors. Invasive SCC predominated over in situ SCC. Finally, 48.5% of patients had a previous history of viral warts.

CONCLUSIONS

Long-term use of immunosuppressive therapy increases the risk for tumor occurrence. Multiple NMSC tumors can develop in patients in tropical countries, even in patients with a high skin phototype. Therefore, RTRs should understand the high risk for the development of malignant tumors and should be properly informed about the prevention and treatment of NMSC.

Surveillance of nonmelanoma skin cancer incidence rates in kidney transplant recipients in Ireland

BACKGROUND

The incidence of nonmelanomatous skin cancer (NMSC) is substantially higher among renal transplant recipients (RTRs) than in the general population. With a growing RTR population, a robust method for monitoring skin cancer rates in this population is required.

METHODS

A modeling approach was used to estimate the trends in NMSC rates that adjusted for changes in the RTR population (sex and age), calendar time, the duration of posttransplant follow-up, and background population NMSC incidence rates. RTR databases in both Northern Ireland (NI) and the Republic of Ireland (ROI) were linked to their respective cancer registries for diagnosis of NMSC, mainly squamous cell carcinoma (SCC) and basal cell carcinoma (BCC).

RESULTS

RTRs in the ROI had three times the incidence (P<0.001) of NMSC compared with NI. There was a decline (P<0.001) in NMSC 10-year cumulative incidence rate in RTRs over the period 1994-2009, which was driven by reductions in both SCC and BCC incidence rates. Nevertheless, there was an increase in the incidence of NMSC with time since transplantation. The observed graft survival was higher in ROI than NI (P<0.05) from 1994-2004. The overall patient survival of RTRs was similar in NI and ROI.

CONCLUSION

Appropriate modeling of incidence trends in NMSC among RTRs is a valuable surveillance exercise for assessing the impact of change in clinical practices over time on the incidence rates of skin cancer in RTRs. It can form the basis of further research into unexplained regional variations in NMSC incidence.

Post-transplant malignancy in liver transplantation: a single center experience

We aim to determine the incidence of malignancy after liver transplantation (LT) compared to general population. The records of patients who received LTs at our center from October 1989 and November 2012 were retrospectively reviewed. The standardized incidence ratio (SIR) of cancer in the patients was compared to general population using the data from the Taiwan Cancer Registry. Survival was estimated using the Kaplan-Meier method. A total of 444 patients were included. Malignancy was found in 46 (28 de novo and 19 recurrent malignancies) patients (10.4%) with the median follow up of 4.2±4.2 years. The median time of cancer occurrence after transplant was 1.2±1.9 years (range, 0.2-9.1 years). Post-transplant lymphoproliferative disorder was the most frequent de novo malignancy (57.1% [16/28]). The cumulative incidence rates of all malignancies were 5.1%, 10.4%, 12.8%, 15.8%, and 15.8% at 1, 3, 5, 10, and 15 years, respectively. The cumulative incidence rates of de novo malignancies were 3.4%, 5.97%, 7.7%, 10.9%, and 10.9 % at 1, 3, 5, 10, and 15 years. Compared to general population, transplant recipients had significantly higher incidence of all de novo cancers (SIR: 3.26, 95% confidence interval [CI]: 2.17-4.72), hematologic (SIR: 58.4; 95% CI, 33.3-94.8), and bladder (SIR: 10.2, 95% CI: 1.1-36.7) cancers. The estimated mean survivals after transplantation in cancer-free, de novo cancer, and recurrent cancer patients were 17.7±0.5, 11.3±1.2, and 3.6±0.6 years, respectively. There is a significantly increased risk of malignancies after LT in the Taiwanese population.

HLA-C -35kb expression SNP is associated with differential control of β-HPV infection in squamous cell carcinoma cases and controls

A single nucleotide polymorphism (SNP) 35 kb upstream of the HLA-C gene is associated with HLA-C expression, and the high expressing genotype (CC) has been associated with HIV-I control. HLA-C is unique among the classical MHC class I molecules for its role in the control of viral infections and recognition of abnormal or missing self. This immunosurveillance is central to the pathogenesis of non-melanoma skin cancer (NMSC), and of squamous cell carcinoma (SCC) in particular. While sun exposure is a major risk factor for these cancers, cutaneous infections with genus β-HPV have been implicated in the development of SCC. We hypothesized that the high expression HLA-C genotype is associated with β-HPV infections. Therefore, we investigated the association between β-HPV serology and the -35 kb SNP (rs9264942) in a population-based case-control study of 510 SCC cases and 608 controls. Among controls, the high expression -35 kb SNP genotype (CC) reduced the likelihood of positive serology for multiple (≥2) β-HPV infections (OR = 0.49, 95% CI: 0.25-0.97), and β-HPV species 2 infection (OR = 0.43, 95% CI: 0.23-0.79). However, no association with β-HPV status was observed among SCC cases. Our findings suggest that underlying immunogenotype plays an important role in differential control of β-HPV in SCC cases and controls.

Optimal management of skin cancer in immunosuppressed patients

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

Epidemiology of basal cell carcinoma in the United Kingdom: incidence, lifestyle factors, and comorbidities

Background:

Little is known about the epidemiology of basal cell carcinoma (BCC).

Methods:

Using the Clinical Practice Research Datalink, we calculated annual incidence rates. In a case–control analysis, we examined lifestyle factors and comorbidities.

Results:

Incidence rose significantly between 2000 and 2011. Basal cell carcinoma risk was increased in alcohol drinkers (slightly) and immunocompromised patients, but reduced in smokers and individuals with abnormal weight.

Conclusions:

Basal cell carcinoma places a growing public health burden. Lifestyle factors do not play a major role in pathogenesis, but immunosuppression is important.

Nitric oxide donor exisulind is an effective inhibitor of murine photocarcinogenesis

NO-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) have been shown to have anti-inflammatory, antiproliferative and apoptosis-inducing effects in tumor cells. Herein, we have investigated the effects of NO-exisulind on the growth of UVB-induced skin tumor development in a murine model. We found that the topical treatment with NO-exisulind significantly reduced UVB-induced tumors in SKH-1 hairless mice. The tumors/tumor bearing mouse, the number of tumors/mouse and tumor volume/mouse decreased significantly (P < 0.05) as compared with vehicle-treated and UVB-irradiated positive controls. Consistently, NO-exisulind-treated animals showed reduced expression of proliferation markers, such as PCNA and cyclin D1. These mice also manifested increased expression of proapoptotic Bax and decreased expression of antiapoptotic Bcl2 with an increase in the number of TUNEL-positive cells in tumors. We also investigated whether NO-exisulind-treated tumors are less invasive and progress less efficiently from benign to malignant carcinomas. For this, tumors were stained for various epithelial-mesenchymal transition (EMT) markers. NO-exisulind decreased the expression of mesenchymal markers, such as Fibronectin, N-cadherin, SNAI, Slug and Twist and enhanced the epithelial marker E-cadherin. Similarly, UVB-induced phosphorylation of Erk1/2 and p38 was decreased in NO-exisulind-treated animals. These data suggest that NO-exisulind reduces tumor growth and inhibits tumor progression by blocking proliferation, inducing apoptosis and reducing EMT.

Combined inhibition of p38 and Akt signaling pathways abrogates cyclosporine A-mediated pathogenesis of aggressive skin SCCs

Non-melanoma skin cancers (NMSCs) are the most common neoplasm in organ transplant recipients (OTRs). These cancers are more invasive and metastatic as compared to those developed in normal cohorts. Previously, we have shown that immunosuppressive drug, cyclosporine A (CsA) directly alters tumor phenotype of cutaneous squamous cell carcinomas (SCCs) by activating TGF-β and TAK1/TAB1 signaling pathways. Here, we identified novel molecular targets for the therapeutic intervention of these SCCs. We observed that combined blockade of Akt and p38 kinases-dependent signaling pathways in CsA-promoted human epidermoid carcinoma A431 xenograft tumors abrogated their growth by more than 90%. This diminution in tumor growth was accompanied by a significant decrease in proliferation and an increase in apoptosis. The residual tumors following the combined treatment with Akt inhibitor triciribine and p38 inhibitors SB-203580 showed significantly diminished expression of phosphorylated Akt and p38 and these tumors were less invasive and highly differentiated. Diminished tumor invasiveness was associated with the reduced epithelial-mesenchymal transition as ascertained by the enhanced E-cadherin and reduced vimentin and N-cadherin expression. Consistently, these tumors also manifested reduced MMP-2/9. The decreased p-Akt expression was accompanied by a significant reduction in p-mTOR. These data provide first important combinatorial pharmacological approach to block the pathogenesis of CsA-induced highly aggressive cutaneous neoplasm in OTRs.

Rapamycin and mTORC1 inhibition in the mouse: skin cancer prevention

Therapeutic and preventive effects of rapamycin include reduced risk of nonmelanoma skin cancer (NMSC). In this issue of the journal (beginning on page 1011), Checkley and colleagues report that rapamycin inhibits mTOR complex 1 in murine epidermis, thereby inhibiting tumor promotion mediated by tetradecanoyl phorbol-13 acetate in association with a strong anti-inflammatory effect. Rapamycin is an immunosuppressive drug for preventing graft rejection in organ transplant recipients and reduces the risk of NMSC and Kaposi's sarcoma in this population, albeit by mechanisms distinct from immunosuppression. Important future directions include identifying molecular predictors of rapamycin/rapalog sensitivity or resistance (potentially, for example, PI3K pathway alterations and KRAS mutations) and combined non-rapalog, mTOR-targeting approaches, all of which should increase efficacy and minimize toxicity.

Exploiting the origins of Ras mediated squamous cell carcinoma to develop novel therapeutic interventions

The small GTPase Ras is activated in a high proportion of human cancers. Attempts to clinically block Ras activity through pharmacological means has proven largely ineffective thus far. We employed an inducible mouse model of squamous cell carcinoma (SCC) to study the effect of Ras activation and show that hair follicle stem cells (HFSCs) are a cell of origin for SCC, whereas their more restricted progeny cannot serve as cancer cells of origin and are refractory to Ras activation. We propose that by identifying the unique mechanisms by which HFSCs are mobilized to initiate Ras mediated tumorigenesis, the molecular process behind SCC can be more completely elucidated and context dependent activities for Ras more clearly defined. Here, we summarize our recent results and point to future experiments designed to create novel therapeutics by exploiting the differential sensitivities of various cells within the epidermis to Ras activation.

Procarcinogenic effects of cyclosporine A are mediated through the activation of TAK1/TAB1 signaling pathway

Cyclosporine A (CsA) is an immunosuppressive drug commonly used for maintaining chronic immune suppression in organ transplant recipients. It is known that patients receiving CsA manifest increased growth of aggressive non-melanoma skin cancers. However, the underlying mechanism by which CsA augments tumor growth is not fully understood. Here, we show that CsA augments the growth of A431 epidermoid carcinoma xenograft tumors by activating tumor growth factor β-activated kinase1 (TAK1). The activation of TAK1 by CsA occurs at multiple levels by kinases ZMP, AMPK and IRAK. TAK1 forms heterodimeric complexes with TAK binding protein 1 and 2 (TAB1/TAB2) which in term activate nuclear factor κB (NFκB) and p38 MAP kinase. Transcriptional activation of NFκB is evidenced by IKKβ-mediated phosphorylation-dependent degradation of IκB and consequent nuclear translocation of p65. This also leads to enhancement in the expression of its transcriptional target genes cyclin D1, Bcl2 and COX-2. Similarly, activation of p38 leads to enhanced inflammation-related signaling shown by increased phosphorylation of MAPKAPK2 and which in turn phosphorylates its substrate HSP27. Activation of both NFκB and p38 MAP kinase provide mitogenic stimuli to augment the growth of SCCs.