Sirolimus use and risk of cutaneous squamous cell carcinoma (SCC) in solid organ transplant recipients (SOTRs)

Trial protocol for SiroSkin: a randomised double-blind placebo-controlled trial of topical sirolimus in chemoprevention of facial squamous cell carcinomas in solid organ transplant recipients

BACKGROUND

Keratinocyte carcinomas such as basal cell carcinomas and squamous cell carcinomas are a major burden affecting morbidity and mortality in solid organ transplant recipients (SOTRs). Best treatment includes frequent skin checks for early detection and surgery for high incidence of skin cancers. Sirolimus is an immunosuppressive drug which may reduce the burden of skin cancer but may be poorly tolerated when given orally. Topical sirolimus has been proven effective at reducing the burden of skin cancers in animal models, and its safety has long been established in children with tuberous sclerosis. A recent 12-week phase II trial of topical sirolimus suggested it was safe and effective at reducing the early signs of skin cancer in the absence of major side effects. The aim of the SiroSkin trial is to determine whether topical sirolimus can fill a major gap in current therapies by reducing the onset and number of new skin cancers thus reducing burden of disease and cost-effectiveness.

METHODS

Protocol for a multi-centred phase III, participant- and clinician assessor-blinded, placebo-controlled randomised trial in SOTRs. A minimum 146 participants randomised 1:1 will be treated with 1% topical sirolimus versus placebo applied to the face on a regular basis for 24 weeks. Participation is 24 months in total-24 weeks of treatment and 18 months of follow-up. Outcomes include the number of keratinocyte carcinomas at 24 weeks of treatment compared to placebo and then at 12 and 24 months after initiation of treatment. Analysis will be as per protocol and intention to treat.

DISCUSSION

The results of this trial will inform management strategies for skin cancers in SOTRs and provide evidence for cost-effectiveness.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05860881. Registered on June 15, 2023, and on anzctr.org.au (registration number NCT05860881).

Pediatric Kidney Transplantation: Cancer and Cancer Risk

Children with end-stage kidney disease (ESKD) face a lifetime of complex medical care, alternating between maintenance chronic dialysis and kidney transplantation. Kidney transplantation has emerged as the optimal treatment of ESKD for children and provides important quality of life and survival advantages. Although transplantation is the preferred therapy, lifetime exposure to immunosuppression among children with ESKD is associated with increased morbidity, including an increased risk of cancer. Following pediatric kidney transplantation, cancer events occurring during childhood or young adulthood can be divided into two broad categories: post-transplant lymphoproliferative disorders and non-lymphoproliferative solid tumors. This review provides an overview of cancer incidence, types, outcomes, and preventive strategies in this population.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 1: Diagnostics and prevention-Update 2023

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in white populations, accounting for 20% of all cutaneous malignancies. Overall, cSCC mostly has very good prognosis after treatment, with 5-year cure rates greater than 90%. Despite the overall favourable prognosis and the proportionally rare deaths, cSCC is associated with a high total number of deaths due to its high incidence. A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), the European Society for Radiotherapy and Oncology (ESTRO), the European Union of Medical Specialists (UEMS), the European Academy of Dermatology and Venereology (EADV) and the European Organization of Research and Treatment of Cancer (EORTC), was formed to update recommendations on cSCC, based on current literature and expert consensus. Part 1 of the guidelines addresses the updates on classification, epidemiology, diagnosis, risk stratification, staging and prevention in immunocompetent as well as immunosuppressed patients.

Immunomodulators for Non-Melanoma Skin Cancers: Updated Perspectives

Non-melanoma skin cancers (NMSCs) are the most common cancers worldwide and may be associated with significant morbidity and mortality, especially in immunosuppressed populations. Successful management of NMSC must take primary, secondary and tertiary prevention strategies into consideration. In response to an improved understanding of the pathophysiology of NMSC and associated risk factors, multiple systemic and topical immunomodulatory drugs have been developed and integrated into clinical practice. Many of these drugs are efficacious in the prevention and treatment of precursor lesions (actinic keratoses; AKs), low-risk NMSC, and advanced disease. The identification of patients at high risk for the development of NMSC is critical in reducing disease morbidity. Understanding the various treatment options available and their comparative effectiveness is paramount for developing a personalized treatment regimen for such patients. This review article provides an updated overview of the various topical and systemic immunomodulatory drugs available for the prevention and treatment of NMSC, and the published data supporting their use in clinical practice.

Sirolimus diminishes the expression of GRO-α (CXCL-1) /CXCR2 axis in human keratinocytes and cutaneous squamous cell carcinoma cells

BACKGROUND

Organ transplant recipients show a high incidence for the formation of cutaneous squamous cell carcinoma (cSCC), while sirolimus appears to reduce the risk. GRO-α is a chemokine, which is overexpressed in many tumor entities and associated with malignant transformation. However, little is known about the expression and function of GRO-α in human cSCC.

OBJECTIVE

Our aim was to investigate the relevance of the GRO-α (CXCL-1)/ CXCR2 axis in human cSCC and the potential impact of sirolimus.

METHODS

We analyzed the GRO-α expression in human keratinocytes, different cSCC cell lines as well as cSCC tissue and investigated its effect on cell proliferation and migration. Additionally, we incubated cells with sirolimus and measured the expression of GRO-α and its receptor CXCR2.

RESULTS

We showed that both constitutive as well as induced GRO-α expression is higher in in cSCC cell lines compared to keratinocytes and that GRO-α protein is detectable in human cSCC tissue. By GRO-α exposure and shRNA knock down, we identified GRO-α as a driving factor in proliferation and migration. Moreover, in a dermis equivalent GRO-α knocked down cSCC cell lines displayed a reduced capacity in tumor nest formation. Incubation with sirolimus significantly inhibited GRO-α expression in keratinocytes as well as tumor cell lines. Moreover, sirolimus decreased the expression of the corresponding receptor CXCR2.

CONCLUSION

Taken together, our results suggest that the GRO-α/CXCR2 axis plays a role in human keratinocyte carcinogenesis and might represent a molecular mechanism for the preventive effect of mTOR inhibitors in cSCC development.

Cohort and Nested Case-Control Study of Cutaneous Squamous Cell Carcinoma in Solid Organ Transplant Recipients, by Medication

BACKGROUND

Knowledge is needed about squamous cell carcinoma (cSCC) risk in solid organ transplant recipients (SOTRs) using contemporary immunosuppressive regimens.

OBJECTIVE

Evaluate risk of cSCC in relation to medications used by SOTRs.

METHODS

The cohort and nest case-control study included 3,308 SOTRs and 65,883 persons without transplantation during 2009-2019. Incident cSCC was identified from pathology data and medications from pharmacy data. Adjusted hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards analysis, with voriconazole examined as a time-dependent variable.

RESULTS

The annual incidence of cSCC was 1.69% in SOTRs and 0.30% in persons without transplantation. The adjusted HR of cSCC associated with lung transplant was 14.83 (CI 9.85-22.33) for lung and 6.53 to 10.69 for other organs. Risk in Latinx persons was higher than in other non-white groups. Among lung recipients, the HR was 1.14 for each month of voriconazole use (95% CI: 1.04-1.26). Azathioprine use for ≥7 months, relating to mycophenolate mofetil intolerance, was associated with 4.22-fold increased risk of cSCC (95% CI 1.90-9.40). Belatacept and other immunsuppressive medications were not associated with risk.

LIMITATIONS

The number of events was somewhat small.

CONCLUSIONS

Knowledge of risks and benefits in diverse patients can translate to care improvements.

Investigative Landscape in Advanced Non-Melanoma Skin Cancers

OPINION STATEMENT

Advanced non-melanoma skin cancers have been challenging to treat due to limited treatment options. Treatment paradigm has shifted with the approval of immunotherapeutic agents cemiplimab and pembrolizumab which have been a key development and have changed the landscape of advanced or metastatic squamous cell skin cancers. Hedgehog inhibitors, vismodegib and sonidegib, remain upfront options for advanced or metastatic basal cell carcinomas. Current clinical trials are continuing to evaluate the use of immune checkpoint inhibitors and hedgehog pathway inhibitors. There is further need for ongoing research and development of new therapies in both malignancies.

Low-Dose Acitretin for Secondary Prevention of Keratinocyte Carcinomas in Solid-Organ Transplant Recipients

BACKGROUND

Keratinocyte carcinomas, particularly squamous cell carcinoma (SCC), occur more frequently and aggressively in solid-organ transplant recipients (SOTRs) than in the general population. Systemic retinoids are effective in secondary prevention of keratinocyte carcinomas in this population, but their use is limited by adverse effects including a rebound effect in cases of treatment discontinuation.

OBJECTIVE

Our aim was to determine whether low-dose acitretin is efficient in the secondary prevention of keratinocyte carcinomas in SOTRs.

METHODS

This retrospective case-crossover study was conducted at a specialized dermatology clinic for SOTRs in a large transplantation center in 2010-2017. Patients with at least 1 previous keratinocyte carcinoma who were treated with acitretin 10 mg/day for 2 years were included. The main outcome was the difference in the number of new keratinocyte carcinomas diagnosed during treatment compared to during the 2-year pretreatment period.

RESULTS

The cohort included 34 SOTRs. A significant reduction in the mean number of new keratinocyte carcinomas during treatment relative to the pretreatment period was observed (1.7 vs. 3.6, -53% p = 0.002). Similar results were noted on analysis by tumor type, for both SCC and basal cell carcinoma.

CONCLUSION

This study of SOTRs demonstrated positive results for low-dose acitretin as a chemoprevention of keratinocyte carcinomas in this population.

European interdisciplinary guideline on invasive squamous cell carcinoma of the skin: Part 1. epidemiology, diagnostics and prevention

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in the white populations, accounting for 20% of all cutaneous malignancies. Factors implicated in cSCC etiopathogenesis include ultraviolet radiation exposure and chronic photoaging, age, male sex, immunosuppression, smoking and genetic factors. A collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO) and the European Organisation of Research and Treatment of Cancer (EORTC) was formed to update recommendations on cSCC classification, diagnosis, risk stratification, staging and prevention, based on current literature, staging systems and expert consensus. Common cSCCs are typically indolent tumors, and most have a good prognosis with 5-year cure rates of greater than 90%, and a low rate of metastases (<4%). Further risk stratification into low-risk or high-risk common primary cSCC is recommended based on proposed high-risk factors. Advanced cSCC is classified as locally advanced (lacSCC), and metastatic (mcSCC) including locoregional metastatic or distant metastatic cSCC. Current systems used for staging include the American Joint Committee on Cancer (AJCC) 8th edition, the Union for International Cancer Control (UICC) 8th edition, and Brigham and Women's Hospital (BWH) system. Physical examination for all cSCCs should include total body skin examination and clinical palpation of lymph nodes, especially of the draining basins. Radiologic imaging such as ultrasound of the regional lymph nodes, magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography-computed tomography (PET-CT) scans are recommended for staging of high-risk cSCC. Sentinel lymph node biopsy is currently not recommended. Nicotinamide, oral retinoids, and topical 5-FU have been used for the chemoprevention of subsequent cSCCs in high-risk patients but are not routinely recommended. Education about sun protection measures including reducing sun exposure, use of protective clothing, regular use of sunscreens and avoidance of artificial tanning, is recommended.

Mammalian target of rapamycin (mTOR) inhibitors and skin cancer risk in nonrenal solid organ transplant recipients: systematic review and meta-analysis

BACKGROUND

Solid organ transplant recipients have an increased risk of malignancy compared with the general population. Mammalian target of rapamycin (mTOR) inhibitors have been used as immunosuppressants in transplant recipients. There remains a lack of evidence of this treatment in nonrenal solid organ transplantation. We aimed to perform a systematic review and meta-analysis to assess the effects of mTOR inhibitors on secondary nonmelanoma skin cancer (NMSC) malignancies in nonrenal transplant recipients.

METHODS

A systematic review and meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies for the present systematic review and meta-analysis included those in which patient cohorts underwent heart, liver, lung, and pancreas (i.e. nonrenal solid organ) transplantation, with treatment group being those treated with an mTOR inhibitor such as sirolimus or everolimus, and control group being placebo, or alternative non-mTOR inhibitor treatment such as calcineurin inhibitors or as per standard treatment protocol.

RESULTS

From the six included studies, we found no significant difference in the odds of either primary or secondary NMSC (OR 0.73, 95% CI 0.41-1.29, P = 0.28). Pooled analysis of patients with secondary NMSC demonstrated a trend toward significant benefit with mTOR inhibitor treatment (OR 0.61, 95% CI 0.37-1.02, P = 0.06) but no protective effect for primary NMSC (OR 0.53, 95% CI 0.03-9.96, P = 0.67).

CONCLUSIONS

Our results suggest that in nonrenal transplant recipients, mTOR inhibitors may have a protective effect against secondary NMSC but not primary NMSC posttransplantation. Extrapolating the findings of reduced NMSC in renal transplant populations to nonrenal transplant cases should be cautioned.

Evolving Role of Systemic Therapies in Non-melanoma Skin Cancer

Keratinocyte cancers - basal and cutaneous squamous cell carcinoma (BCC, cSCC) - are the most common forms of non-melanoma skin cancer (NMSC) and there has been a significant increase in their incidence globally in recent decades. Although the majority of BCC and cSCC are cured with conventional surgery or radiotherapy, certain tumour or patient-determined factors may result in these modalities being inadequate or inappropriate, for example, locally advanced or metastatic disease, high tumour multiplicity, patient comorbidities and patient preferences. In these clinical circumstances, systemic treatment may be indicated, and over the past 10 years a number of new systemic agents have been approved. Nonetheless, effective systemic therapy for keratinocyte cancers remains an area of significant unmet clinical need. Improved understanding of the molecular and immune pathogenesis underlying tumour growth and development is critical for driving future advances and is a research priority. The aim of this review is to provide clinicians with an overview of systemic treatments for BCC and cSCC and will focus on current evidence for conventional chemotherapy, targeted therapies, immunotherapy, adjuvant and neoadjuvant therapy, chemoprevention and future prospects for novel systemic treatment approaches.

Risk Factors for Developing Nonmelanoma Skin Cancer after Lung Transplantation

Background

Nonmelanoma skin cancer (NSMC) is the most common malignancy after organ transplantation. Lung transplant recipients (LTRs) are particularly prone to develop NMSC as compared to renal or hepatic transplant recipients due to higher dosages of immunosuppression needed. Everolimus, an immunosuppressant used in organ transplant recipients, is thought to inherit a lower risk for NMSC than calcineurin inhibitors, especially in renal transplant recipients. It is currently unknown whether this also applies to LTRs.

Objectives

To determine risk factors for NMSC and precancerous lesions after lung transplantation (LTx) and to characterize the effect of everolimus-based regimens regarding this risk.

Materials and Methods

90 LTRs and former participants of the interventional trial “Immunosuppressive Therapy with Everolimus after Lung Transplantation”, who were randomized to receive either an everolimus- or mycophenolate mofetil- (MMF-) based regimen, were enrolled and screened in this retrospective, single-center cohort study.

Results

After a median follow-up of 101 months, we observed a prevalence of 38% for NMSC or precancerous lesions. 33% of the patients continuously receiving everolimus from LTx to dermatologic examination compared to 39% of all other patients, predominantly receiving an MMF-based regimen, were diagnosed with at least one NMSC or precancerous lesion (P=.66). Independent risk factors for NMSC or precancerous lesions after LTx were male sex and duration of voriconazole therapy.

Conclusion

NMSC or precancerous lesions were very common after LTx, and risk factors were similar to previous reports on LTRs. Everolimus did not decrease this risk under the given circumstances of this study. Patients should be counseled regarding their risk, perform vigorous sunscreen, and undergo regular dermatological controls, regardless of their immunosuppressive regimen.

The mTOR-inhibitor Sirolimus decreases the cyclosporine-induced expression of the oncogene ATF3 in human keratinocytes

BACKGROUND

Due to their immunosuppressive therapy, organtransplant recipients (OTRs) exhibit a high incidence for the development of cutaneous squamous cell carcinoma (cSCC). Randomized studies of kidney-transplanted patients indicate a significant lower susceptibility for cSCC among patients receiving the mTOR-inhibitor Sirolimus, compared to patients without mTOR-regimen. The exact mechanism, how mTOR inhibition affects keratinocyte carcinogenesis remains unclear.

OBJECTIVE

Our aim was to investigate the impact of Sirolimus on the expression level of the oncogene ATF3, which is involved in the development and progression of cSCC.

METHODS

We incubated human keratinocytes, cSSC cell lines and 3D skin equivalents with Sirolimus, exposed the cells to calcineurin inhibitors (CNI) and UVA-radiation and measured the expression level of ATF3 by real-time PCR and western blot.

RESULTS

We show that Sirolimus downregulates the expression of ATF3 induced by cyclosporine or cyclosporine plus UV-radiation in keratinocytes. In line with this we demonstrate a decrease in ATF3 expression, by incubating 3D skin equivalents with Sirolimus prior to cyclosporine and UV-light. However, Sirolimus has no significant impact on the ATF3 expression levels of cyclosporine stimulated cSCC cell lines.

CONCLUSION

Taken together, our study demonstrates that Sirolimus downregulates the CNI or UV-induced ATF3 expression in human keratinocytes, which could be a potential molecular mechanism how Sirolimus reduces cSCC in OTRs. The lack of ATF3 suppression by Sirolimus in cSCC cell lines fits to observations from clinical studies which demonstrated a clinical benefit from the switch to a mTOR-regimen in patients with low tumor burden in early stage of disease.

Guidelines of care for the management of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of human cancer and has an increasing annual incidence. Although most cSCC is cured with office-based therapy, advanced cSCC poses a significant risk for morbidity, impact on quality of life, and death. This document provides evidence-based recommendations for the management of patients with cSCC. Topics addressed include biopsy techniques and histopathologic assessment, tumor staging, surgical and nonsurgical management, follow-up and prevention of recurrence, and management of advanced disease. The primary focus of these recommendations is on evaluation and management of primary cSCC and localized disease, but where relevant, applicability to recurrent cSCC is noted, as is general information on the management of patients with metastatic disease.

Human Immunodeficiency Virus (HIV)- and Non-HIV-Associated Immunosuppression and Risk of Cervical Neoplasia

OBJECTIVE

To estimate the risk of cervical intraepithelial neoplasia grade 2, 2-3, 3, adenocarcinoma in situ, or cancer (CIN 2 or worse) among women with human immunodeficiency virus (HIV)- and non-HIV-associated immunosuppression.

METHODS

We performed a case-control study of 20,146 women with incident CIN 2 or worse and 5:1 age-matched, incidence-density selected women in a control group (n=100,144) enrolled in an integrated health care system from 1996 to 2014. Adjusted rate ratios (RRs) from conditional logistic regression were obtained for HIV status (stratified by CD4 T-cells), solid organ transplant history, and immunosuppressive medication use.

RESULTS

Risk of CIN 2 or worse was increased among women with HIV (n=36 women in the case group and 79 women in the control group; adjusted RR 2.0, 95% CI 1.3-3.0) compared with those without HIV and in solid organ transplant recipients (n=51 women in the case group and 68 women in the control group; RR 3.3, 95% CI 2.3-4.8) compared with women without a prior transplant. The highest risks were among women with HIV and less than 200 CD4 T-cells/microliter (n=9 women in the case group and eight women in the control group; RR 5.6, 95% CI 2.1-14.7) compared with those without HIV and in solid organ transplant recipients prescribed three or greater immunosuppressive medication classes (n=32 women in the case group and 33 women in the control group; RR 4.1, 95% CI 2.5-6.8) compared with women without a prior transplant and zero medication classes. No increased risks were observed for women with HIV and 500 or greater CD4 T-cells/microliter (n=9 women in the case group and 43 women in the control group; RR 0.8, 95% CI 0.4-1.7) compared with those without HIV or women without prior solid organ transplantation prescribed two or fewer immunosuppressive medication classes (n=1,262 women in the case group and 6,100 women in the control group; RR 0.95, 95% CI 0.89-1.01) compared with women without and a prior transplant and zero medication classes.

CONCLUSION

Risk of CIN 2 or worse is increased in women with a prior solid organ transplant or who have HIV and CD4 cells/microliter less than 500 but not in women with HIV and higher CD4 levels or in women without a prior solid organ transplant but who are prescribed only one or two immunosuppressive medication classes.

Research gaps in the management and prevention of cutaneous squamous cell carcinoma in organ transplant recipients

Although tremendous progress has been made in recent years in skin cancer care for organ transplant recipients, significant gaps remain in data-driven clinical guidelines, particularly for the treatment and prevention of cutaneous squamous cell carcinoma (cSCC), the most common malignancy among this population. In this review, we aim to summarize current knowledge around the management of cSCC and highlight the most significant gaps in knowledge that continue to pose challenges in the delivery of skin cancer care for organ transplant recipients. We suggest future directions for research that will bridge existing gaps and establish evidence-driven guidelines for primary prevention, screening and treatment of cSCC in this high-risk patient population.

High-risk cutaneous malignancies and immunosuppression: Challenges for the reconstructive surgeon in the renal transplant population

Renal transplantation is the most frequently performed transplant procedure. Immunosuppressive therapies have dramatically increased survival rates in transplant recipients but are associated with an increased risk of skin cancers. Recent changes in immunosuppressive strategies have been adopted with the aim of reducing this challenging adverse effect. Despite these new strategies, cutaneous malignancies tend to be numerous, aggressive and associated with a higher risk of local and distant dissemination than in the non-transplant population. This represents a significant workload for transplant physicians, dermatologists, and head and neck and plastic surgeons. This review highlights key concepts in the pathogenesis of skin cancer in transplant patients, the impact current and evolving immunosuppressive strategies and regimens will have on the epidemiology, and the management of cutaneous malignancies in renal transplant patients, with particular focus on the implications for the plastic surgery community.

Incidence of melanoma in organ transplant recipients in Alberta, Canada

BACKGROUND

Many studies have documented the increased risk of non-melanoma skin cancers in organ transplant recipients (OTRs). However, the incidence of melanoma is less well defined. To date, there have been no studies on the incidence of melanoma in Canadian OTRs. Herein, we determine the incidence and clinical features of melanoma in a cohort of OTRs in Southern Alberta, Canada.

METHODS

We used the Southern Alberta Transplant database to identify kidney and liver transplant recipients between the years 2000 and 2012. This population was cross-referenced with the Alberta Cancer Registry for a diagnosis of melanoma. The clinical features of all cases were obtained, and the standardized incidence rate was calculated.

RESULTS

We identified 993 OTR patients, representing 5955 person-years. Only one patient developed a melanoma post-transplant, and this was a nodular melanoma. The age-standardized incidence rate was 11 per 100 000 (0.6 per 5955), compared to 13.4 per 100 000 in the general Alberta population (incidence rate ratio of 1.29, with 95% confidence interval of 0.17 to 9.82).

CONCLUSIONS

This is the first Canadian study to investigate the association between organ transplantation and melanoma. Our study did not identify an increased risk of developing a de novo melanoma post-transplant.

A qualitative systematic review of the efficacy of sun protection education in organ transplant recipients

BACKGROUND

Transplant recipients are at increased risk of developing skin cancer as a result of chronic immunosuppression. Educating patients on sun protection has been routine posttransplantation, but to our knowledge, no systematic review has yet analyzed the efficacy of such education measures in this high-risk population.

OBJECTIVE

We sought to examine the efficacy of educating transplant recipients on skin cancer and sun protection.

METHODS

A literature search of interventional patient education studies published between January 1995 and March 2016 was performed in PubMed, CINAHL, Cochrane, and EMBASE databases.

RESULTS

Data from 7 studies meeting inclusion criteria were analyzed. No study attempted to examine the direct effect of sun protection education on skin cancer incidence in transplant recipients. Two randomized controlled trials showed that educational intervention can improve sun-protective behavior and decrease skin pigmentation or skin damage in sun-exposed areas. Three other randomized controlled trials compared the efficacy of 2 different forms of patient education at changing sun-protective behavior, but did not examine patient-oriented outcomes.

LIMITATIONS

A lack of high-quality randomized controlled trials with patient-oriented evidence and a dependence on self-reported data are limitations.

CONCLUSION

Sun protection education can be effective at altering patient behavior in transplant recipients, but its effect on posttransplantation skin cancer incidence remains to be elucidated.

Cyclosporine A immunosuppression drives catastrophic squamous cell carcinoma through IL-22

Immune-suppressed organ transplant recipients (OTRs) can develop catastrophic squamous cell carcinoma (SCC), characterized by multiple primary tumors, extensive body surface area involvement, or metastases. There are currently no curative systemic therapies available. We previously showed that IL-22 enhances SCC proliferation. Herein, we examined links between cyclosporine (CSA), IL-22, and SCC in patients, cell lines, and mice with UV light-induced SCC. Eighteen of 114 OTRs developed catastrophic SCC, which was strongly associated with CSA treatment. We found that CSA drives T cell polarization toward IL-22-producing T22 cells, and CSA treatment increased IL-22 receptor in SCC cells. SCC tissue from OTRs showed increased expression of IL-22RA1. CSA potentiated rescue by IL-22 of serum-starved SCC cells; treatment of SCC cells with IL-22 and CSA increased both their migratory and invasive capacity. In a UV-induced model of SCC in SKH-1 immunocompetent mice, treatment with anti-IL-22 antibody reduced tumor number and tumor burden. We found that catastrophic SCC in OTRs is associated with CSA use, which may be acting by favoring T22 polarization. Since anti-IL-22 antibody administration decreased tumor number and tumor burden in vivo, blockade of the IL-22 axis may be developed as a viable therapeutic option for catastrophic SCC.