Skin cancer in organ transplant recipients: Epidemiology, pathogenesis, and management

Factors associated with residual tumor at time of Mohs micrographic surgery for basal cell and squamous cell carcinomas

BACKGROUND

Residual tumor is not always clinically apparent following biopsy of cutaneous carcinomas, which may prompt patients to question the need for definitive treatment.

OBJECTIVE

We investigated the percentage of cases in which residual tumor was histologically present at the time of Mohs micrographic surgery (MMS) for basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) and investigated factors associated with residual tumor.

METHODS

We examined 483 MMS cases performed for biopsy-proven BCC (n = 287) and SCC (n = 196) between October 2022 and April 2023. Single-stage MMS specimens were step-sectioned en face to exhaust the block. Univariate and multivariable logistic regression models were created.

RESULTS

Residual tumor was identified in 83.3% of BCC and 66.8% of SCC at the time of MMS (P = .01). In patients clinically appearing tumor-free following biopsy, residual histologic tumor was identified in 68.2% of BCC and 41.5% of SCC. Residual tumor was significantly more likely in men (P = .04), high-risk sites (P = .002), smaller biopsy sizes (P = .0003), and larger preoperative sizes (P < .0001).

LIMITATIONS

Single center, retrospective cohort.

CONCLUSION

The majority of patients with BCC and SCC have residual histologic tumor at the time of MMS, oftentimes even when tumor is not clinically apparent. Multiple factors impact the presence/absence of residual tumor.

Cutaneous squamous cell carcinoma of the eyelid in northern latitudes, a 25-year experience in Finland

PURPOSE

To evaluate the incidence, clinical features, diagnostic challenges, management and prognosis of cutaneous squamous cell carcinoma of the eyelid (ecSCC) in southern Finland, northern Europe, latitude 62° N.

METHODS

Patients were identified from the Finnish Cancer Registry and the Helsinki University Hospital databases during a 25-year period (1998-2022). Age, sex, location, clinical and histopathological diagnosis, treatment and outcome were retrieved.

RESULTS

Cutaneous squamous cell carcinoma of the eyelid (ecSCC) was diagnosed in 58 patients. The mean age-standardized incidence was 1.03 per 100 000. Median age at the time of histopathological diagnosis was 79 (range 55-93) years; sex ratio was 0.52. Clinical diagnosis in the referral was ecSCC in only three patients. The most frequent misdiagnosis (38%) was basal cell carcinoma (BCC). One or more of the known risk factors (smoking, history of extensive sun exposure, systemic immunosuppression and previous in situ cSCC/cSCC) were documented in 71% of the patients. More than one third (38%) of the patients developed in situ SCC elsewhere on the skin; one third (31%) of the patients had invasive cSCC elsewhere. During the median follow-up time of 24 months, three patients experienced local recurrence, four patients developed metastatic disease (median 19 months) and two patients died of metastatic ecSCC.

CONCLUSION

The estimated incidence of ecSCC in Finland (predominantly white Caucasian) was higher than in a previous study from Europe. Clinical diagnosis of ecSCC is difficult and often misdiagnosed as BCC. Immunosuppression as a risk factor should noticed. Recurrences of ecSCC, which may be lethal, were infrequent.

Squamous cell carcinoma in solid organ transplant recipients: Review of the literature

Solid organ transplant recipients (SOTRs) exhibit an elevated incidence and aggressiveness of squamous cell carcinomas (SCCs) due to their immunosuppression. These tumors are associated with a heightened risk of metastasis and increased mortality. Therefore, an appropriate management of these patients is essential to improve their prognosis. Given the scarcity of studies on non-melanoma skin cancers (NMSCs) in SOTRs, this article aims to summarize and analyze the evidence gathered to date regarding therapeutic approaches, personalized monitoring, and prevention strategies for SCCs in these patients. Additionally, recent advancements in understanding SCCs within this patient group are also documented.

Cancer Surveillance in Solid Organ Transplant Recipients With a Pretransplant History of Malignancy: Multidisciplinary Collaborative Expert Opinion

With improved medical treatments, the prognosis for many malignancies has improved, and more patients are presenting for transplant evaluation with a history of treated cancer. Solid organ transplant (SOT) recipients with a prior malignancy are at higher risk of posttransplant recurrence or de novo malignancy, and they may require a cancer surveillance program that is individualized to their specific needs. There is a dearth of literature on optimal surveillance strategies specific to SOT recipients. A working group of transplant physicians and cancer-specific specialists met to provide expert opinion recommendations on optimal cancer surveillance after transplantation for patients with a history of malignancy. Surveillance strategies provided are mainly based on general population recurrence risk data, immunosuppression effects, and limited transplant-specific data and should be considered expert opinion based on current knowledge. Prospective studies of cancer-specific surveillance models in SOT recipients should be supported to inform posttransplant management of this high-risk population.

Mohs micrographic surgery in immunosuppressed vs immunocompetent patients: Results of a prospective nationwide cohort study (REGESMOHS, Spanish registry of Mohs surgery)

BACKGROUND

Immunosuppressed (IS) patients, particularly solid organ transplant recipients and those on immunosuppressive therapy, face a higher incidence and recurrence of nonmelanoma skin cancers (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Mohs micrographic surgery (MMS) is the preferred treatment for high-risk NMSC due to its high cure rate and margin examination capabilities. However, IS patients may experience more complications, such as surgical site infections, and a greater risk of recurrence, making their outcomes a subject of interest.

OBJECTIVES

This study aimed to compare IS and immunocompetent (IC) patients undergoing MMS for NMSC in terms of baseline characteristics, intra- and post-surgical complications, and postoperative recurrence rates.

METHODS

The study utilized data from the REGESMOHS registry, a 7-year prospective cohort study in Spain. It included 5226 patients, categorizing them into IC (5069) and IS (157) groups. IS patients included solid organ transplant recipients, those on immunosuppressive treatments, individuals with haematological tumours and HIV-positive patients. Patient data, tumour characteristics, surgical details and outcomes were collected and analysed.

RESULTS

IS patients demonstrated a higher proportion of SCC, multiple synchronous tumours and tumours invading deeper structures. Complex closures, unfinished MMS and more surgical sections were observed in the IS group. Although intra-operative morbidity was higher among IS patients, this difference became non-significant when adjusted for other variables such as year of surgery, antiplatelet/anticoagulant treatment or type of closure. Importantly, IS patients had a substantially higher recurrence rate (IRR 2.79) compared to IC patients.

CONCLUSIONS

This study suggests that IS patients may be at a higher risk of development of AE such as bleeding or tumour necrosis and are at a higher risk of tumour recurrence. Close follow-up and consideration of the specific characteristics of NMSC in IS patients are crucial. Further research with extended follow-up is needed to better understand the long-term outcomes for this patient group.

Advancements in elucidating the pathogenesis of actinic keratosis: present state and future prospects

Solar keratosis, also known as actinic keratosis (AK), is becoming increasingly prevalent. It is a benign tumor that develops in the epidermis. Individuals with AK typically exhibit irregular, red, scaly bumps or patches as a result of prolonged exposure to UV rays. These growths primarily appear on sun-exposed areas of the skin such as the face, scalp, and hands. Presently, dermatologists are actively studying AK due to its rising incidence rate in the United States. However, the underlying causes of AK remain poorly understood. Previous research has indicated that the onset of AK involves various mechanisms including UV ray-induced inflammation, oxidative stress, complex mutagenesis, resulting immunosuppression, inhibited apoptosis, dysregulated cell cycle, altered cell proliferation, tissue remodeling, and human papillomavirus (HPV) infection. AK can develop in three ways: spontaneous regression, persistence, or progression into invasive cutaneous squamous cell carcinoma (cSCC). Multiple risk factors and diverse signaling pathways collectively contribute to its complex pathogenesis. To mitigate the risk of cancerous changes associated with long-term UV radiation exposure, prompt identification, management, and prevention of AK are crucial. The objective of this review is to elucidate the primary mechanisms underlying AK malignancy and identify potential treatment targets for dermatologists in clinical settings.

Skin Cancer Awareness and Knowledge About Sun Protection Practices in Solid Organ Transplant Recipients: Patient Survey Study

BACKGROUND

Adequate sun protection practices in chronically immunosuppressed patients can minimize the burden of the most common type of skin cancer in this population. In addition, early recognition of skin cancer by patients can lead to decreased morbidity, and possibly mortality from the disease. Nevertheless, there are significant gaps in the knowledge of sun protection measures and early recognition of skin cancer.

OBJECTIVE

The aim of this study is to determine the risk factors of solid organ transplant recipients (SOTRs) for developing skin cancer and their sun exposure education and behavior post-transplantation.

MATERIALS AND METHODS

This study evaluates the responses of 107 SOTRs on their outlooks and beliefs of sunscreen usage, skin cancer, and sun exposure knowledge.

RESULTS

Our study identified several significant risk factors for the development of actinic keratosis or keratinocyte carcinoma in SOTRs including history of sunburn before age 18, blue eyes, history of tanning bed use, performing monthly skin exams, ability to identify precancerous skin lesions, and history of previous skin examinations.

CONCLUSION

A patient-centered approach needs to be used to properly educate patients on effective ways to reduce excessive sun exposure. Regular skin examinations, and patients continued education are necessary components in reducing the burden of skin cancer in SOTRs.

Dermatological Conditions Seen in Kidney Transplant Recipients: Prevalence and Risk Factors

OBJECTIVES

In kidney transplant, the use of immunosuppressive drugs, indispensable to avoid organ rejection, implies an increased risk of several infectious and neoplastic diseases. Cutaneous infections have a high incidence in kidney transplant recipients and are diagnosed in 55% to 97% of these patients. The objectives of this study were to identify the most frequent skin diseases and their clinical risk factors within a population of kidney transplant recipients.

MATERIALS AND METHODS

We reviewed the medical records of 200 kidney transplant recipients at Sahloul Teaching Hospital, Tunisia, between November 2007 and January 2018. We analyzed the clinical data of patients who sought skin consultations with either dermatologists or plastic surgeons within the hospital. We collected patient sociodemographic data, type of donor, and type of immunosuppressive therapy used by recipients. We also obtained history of skin lesions and examination findings.

RESULTS

Among 200 patients included in our study cohort, 131 were male and 69 were female. Age ranged from 6 to 75 years with a mean age of 30.51 ± 12 years. Patients had received kidneys from either living or deceased donors, with available data indicating 96.5% living donors and 3.5% deceased donors. The mean time interval from transplant to first skin consultation was 31 month (range, 3 months to 10 years). Prevalence of various skin conditions was 48.5%. We found that 62.9% of cases were skin infections, 59.8% were drug-induced skin conditions, and 2.9% were skin cancers. The estimated risk factors for skin lesions include use of cyclosporin and duration of immunosuppression.

CONCLUSIONS

Our study demonstrated the spectrum of skin conditions that can be expected after kidney transplant. Careful dermatological screening and long-term follow-up are needed for these patients to reduce posttransplant skin complications.

Sex as a Predictor of Response to Immunotherapy in Advanced Cutaneous Squamous Cell Carcinoma

Approximately 3-5% of patients with cutaneous squamous cell carcinoma (CSCC) develop advanced disease, accounting for roughly 1% of all cancer deaths in Australia. Immunotherapy has demonstrated significant clinical benefit in advanced CSCC in several key phase II studies; however, there are limited data for patients treated outside of clinical trials. This is particularly relevant in advanced CSCC, which is most often seen in elderly patients with significant comorbidities. Thus, we aim to describe our experience with immunotherapy in a cohort of patients with advanced CSCC in Australia. We retrospectively reviewed all advanced CSCC patients treated with immunotherapy within the Illawarra and Shoalhaven Local Health District. Among the 51 patients treated with immunotherapy, there was an objective response rate (ORR) of 53% and disease control rate (DCR) of 67%. Our most significant predictor of response was sex, with male patients more likely to have better responses compared to female patients (DCR 85% vs. 41%, p < 0.0001), as well as improved progression-free survival (HR 4.6, 95%CI 1.9-10.8, p = 0.0007) and overall survival (HR 3.0, 95%CI 1.3-7.1, p = 0.006). Differential expression analysis of 770 immune-related genes demonstrated an impaired CD8 T-cell response in female patients. Our observed ORR of 53% is similar to that described in current literature with durable responses seen in the majority of patients.

Immunity against Non-Melanoma Skin Cancer and the Effect of Immunosuppressive Medication on Non-Melanoma Skin Cancer Risk in Solid Organ Transplant Recipients

Non-melanoma skin cancers (NMSCs) occur frequently in the Caucasian population and are considered a burden for health care. Risk factors include ultraviolet (UV) radiation, ethnicity and immunosuppression. The incidence of NMSC is significantly higher in solid organ transplant recipients (SOTRs) than in immunocompetent individuals, due to immunosuppressive medication use by SOTRs. While the immunosuppressive agents, calcineurin inhibitors and purine analogues increase the incidence of NMSC in transplant recipients, mTOR inhibitors do not. This is most likely due to the different immunological pathways that are inhibited by each class of drug. This review will focus on what is currently known about the immune response against cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC), two of the main types of NMSC. Furthermore, we will describe the different classes of immunosuppressants given to SOTRs, which part of the immune system they target and how they can contribute to NMSC development. The risk of developing NMSC in SOTRs is the result of a combination of inhibiting immunological pathways involved in immunosurveillance against NMSC and the direct (pro/anti) tumor effects of immunosuppressants.

Skin Cancer in Non-White Solid Organ Transplant Recipients: Mayo Clinic Experience

OBJECTIVE

Solid organ transplant recipients (SOTRs) have an increased risk of skin cancer development, but limited data exist on the development pattern of cutaneous malignancies in non-White SOTRs. The aim of this study was to describe the characteristics and outcomes of non-White patients who developed skin cancer following solid organ transplantation.

METHODS

We conducted a retrospective chart review of non-White SOTRs at the Mayo Clinic who underwent transplantation between November 1987 and April 2020 and subsequently developed skin cancer.

RESULTS

We identified 32 non-White SOTRs who developed skin cancer in the posttransplant period. Among these, 46.9% were Hispanic/Latinx, 25% were American Indian/Alaskan Native, 21.9% were Asian, and 6.3% were Black/African American. Four patients had a history of nonmelanoma skin cancer pretransplant. In regard to skin cancer type, 21 (65.6%) patients developed squamous cell carcinoma, 15 (46.9%) developed basal cell carcinoma, 5 (15.6%) developed melanoma, and 2 (6.3%) developed sebaceous carcinoma. The median time from transplant to first posttransplant skin cancer was 7.8 years.

CONCLUSIONS

Our study provides further characterization of the development of skin cancer in non-White SOTRs following transplant and identifies a variety of relevant pre- and posttransplant factors. Despite a long follow-up period, the number of patients identified remained low, which is consistent with the literature, indicating a low incidence of skin cancer development in non-White SOTRs. Continued investigation may allow for a more precise identification of risk factors and their degree of significance.

[The Cutaneous Squamous Cell Carcinoma - An Update]

BACKGROUND

The cutaneous squamous cell carcinoma (CSCC) is the second most common nonmelanoma skin cancer with an increasing incidence rate. Patients presenting with high-risk lesions associated with locally advanced or metastatic CSCC face high rates of recurrence and mortality.

METHODS

Selective literature review based on PubMed and consideration of current guidelines "Aktinische Keratosen und Plattenepithelkarzinom der Haut" and "Prävention von Hautkrebs".

FINDINGS

Complete surgical excision with histopathological control of excision margins is the gold standard in the treatment of primary CSCC. Radiotherapy can be used as an alternative treatment of inoperable CSCCs. In 2019, the PD1-antibody cemiplimab, has been approved for the treatment of locally advanced and metastatic CSCC by the European Medicines Agency. After 3 years of follow up, Cemiplimab shows overall response rates of 46 %, the median overall survival and median response rate had not been reached yet. Additional immunotherapeutics, combinations with other agents and oncolytic viruses are all potentially worth study to try, so clinical trial data will be forthcoming over the next few years to guide optimal use of these agents.

CONCLUSION

Multidisciplinary board decisions are mandatory for all patients with advanced disease who require more than surgery. Further development of existing therapeutic concepts, identification of new combination therapies and the development of new immunotherapeutics will be the key challenge over the next few years.

Pleckstrin Homology [PH] domain, structure, mechanism, and contribution to human disease

The pleckstrin homology [PH] domain is a structural fold found in more than 250 proteins making it the 11th most common domain in the human proteome. 25% of family members have more than one PH domain and some PH domains are split by one, or several other, protein domains although still folding to give functioning PH domains. We review mechanisms of PH domain activity, the role PH domain mutation plays in human disease including cancer, hyperproliferation, neurodegeneration, inflammation, and infection, and discuss pharmacotherapeutic approaches to regulate PH domain activity for the treatment of human disease. Almost half PH domain family members bind phosphatidylinositols [PIs] that attach the host protein to cell membranes where they interact with other membrane proteins to give signaling complexes or cytoskeleton scaffold platforms. A PH domain in its native state may fold over other protein domains thereby preventing substrate access to a catalytic site or binding with other proteins. The resulting autoinhibition can be released by PI binding to the PH domain, or by protein phosphorylation thus providing fine tuning of the cellular control of PH domain protein activity. For many years the PH domain was thought to be undruggable until high-resolution structures of human PH domains allowed structure-based design of novel inhibitors that selectively bind the PH domain. Allosteric inhibitors of the Akt1 PH domain have already been tested in cancer patients and for proteus syndrome, with several other PH domain inhibitors in preclinical development for treatment of other human diseases.

Management of Cutaneous Head and Neck Squamous and Basal Cell Carcinomas for Immunocompromised Patients

The incidence of non-melanoma skin cancer (NMSC) continues to rise, and more than one million cases are diagnosed in the United States each year. The increase in prevalence has been attributed to increased lifespan and improvements in survival for conditions that increase the risk of these malignancies. Patients who are immunocompromised have a higher risk of developing NMSC compared to the general population. In immunosuppressed patients, a combination of prevention, frequent surveillance, and early intervention are necessary to reduce morbidity and mortality. In this review, we collate and summarize current knowledge regarding pathogenesis of head and neck cutaneous SCC and BCC within immunocompromised patients, examine the potential role of the immune response in disease progression, and detail the role of novel immunotherapies in this subset of patients.

Catching Cancer Early: The Importance of Dermato-Oncology Screening

The European Society for Medical Oncology experts have identified the main components of the long-term management of oncological patients. These include early diagnosis through population screening and periodic control of already diagnosed patients to identify relapses, recurrences, and other associated neoplasms. There are no generally accepted international guidelines for the long-term monitoring of patients with skin neoplasms (nonmelanoma skin cancer, malignant melanoma, precancerous-high-risk skin lesions). Still, depending on the experience of the attending physician and based on the data from the literature, one can establish monitoring intervals to supervise these high-risk population groups, educate the patient and monitor the general population.

Resection of Skin Cancer Resulting in Free Vascularized Tissue Reconstruction: Always a Therapeutic Failure?

The globally increasing incidence of cutaneous malignancies leads, in parallel, to increasing numbers of locally advanced skin cancer resulting in reconstructive surgery. Reasons for locally advanced skin cancer may be a patient's neglect or aggressive tumor growth, such as desmoplastic growth or perineural invasion. This study investigates characteristics of cutaneous malignancies requiring microsurgical reconstruction with the aim of identifying possible pitfalls and improving diagnostic and therapeutic processes. A retrospective data analysis from 2015 to 2020 was conducted. Seventeen patients (n = 17) were included. The mean age at reconstructive surgery was 68.5 (±13) years. The majority of patients (14/17, 82%) presented with recurrent skin cancer. The most common histological entity was squamous cell carcinoma (10/17, 59%). All neoplasms showed at least one of the following histopathological characteristics: desmoplastic growth (12/17, 71%), perineural invasion (6/17, 35%), or tumor thickness of at least 6 mm (9/17, 53%). The mean number of surgical resections until cancer-free resection margins (R0) were achieved was 2.4 (±0.7). The local recurrence rate and the rate of distant metastases were 36%. Identified high-risk neoplastic characteristics, such as desmoplastic growth, perineural invasion, and a tumor depth of at least 6 mm, require a more extensive surgical treatment without concerns about defect size.

Molecular Alterations in Cutaneous Squamous Cell Carcinoma in Immunocompetent and Immunosuppressed Hosts-A Systematic Review

The characterization of cutaneous squamous cell carcinoma (cSCC) at the molecular level is lacking in the current literature due to the high mutational burden of this disease. Immunosuppressed patients afflicted with cSCC experience considerable morbidity and mortality. In this article, we review the molecular profile of cSCC among the immunosuppressed and immunocompetent populations at the genetic, epigenetic, transcriptomic, and proteometabolomic levels, as well as describing key differences in the tumor immune microenvironment between these two populations. We feature novel biomarkers from the recent literature which may serve as potential targets for therapy.

Patterns of photoprotective behavior, cumulative sun-exposure and skin cancer risk among solid organ transplant recipients: a dermatology transplant clinic experience

BACKGROUND

The risk for keratinocyte cancer is dramatically increased in solid organ transplant recipients (OTR) with a first post-transplant keratinocyte cancer conferring a high risk for subsequent keratinocyte cancer arising with accelerated dynamics. Despite cumulative ultraviolet radiation (UVR) being the primary responsible environmental carcinogen reduced compliance with photoprotective measures among OTR has been reported. Risk assessment tools could help guide clinical decision-making and targeted prevention strategies for patients at particularly high risk for post-transplant keratinocyte cancer.

OBJECTIVES

To evaluate cumulative sun exposure by means of an assigned total sun burden (TSB) score, sunscreen use and associated risk factors for keratinocyte cancer in the post-transplantation phase of OTR.

METHODS

A retrospective single-center cohort study analyzing medical records and standardized questionnaires of 290 OTR cared for at a German dermatology transplant clinic.

RESULTS

Significantly lower TSB scores were noted in OTR not developing a first keratinocyte cancer compared to OTR developing keratinocyte cancer during their follow-up period ( P  = 0.005). Regression analysis assigned a significantly higher risk for the development of first keratinocyte cancer to OTR with TSB scores >10. In total 70.7% of OTR with a history of ≥1 keratinocyte cancer reported intermittent sunscreen use, while daily sunscreen use was overall associated with female gender (21.3%) and age >30 years (17.6%).

CONCLUSIONS

The risk of OTR for developing keratinocyte cancer is reflected by their UV-exposure patterns, which may be assessed by the TSB-score, a scored risk assessment tool. Complementing clinical data, the TSB score may help clinicians to identify OTR at particularly high risk for keratinocyte cancer and to endorse intensified prevention strategies and dermato-oncologic care.

First-line programmed death-1 inhibitor treatment for locoregionally advanced or metastatic cutaneous squamous cell carcinoma - A real-world experience from Israel

Objective

Cutaneous squamous cell carcinoma (cSCC) is the second most common non-melanoma skin cancer worldwide. It is usually treated surgically, with very high cure rates. However, in 3%-7% of cases, cSCC metastasizes to lymph nodes or distant organs. Many of the affected patients are elderly with comorbidities who are not candidates for standard-of-care curative-intent treatment with surgery and/or radio-/chemotherapy. Immune checkpoint inhibitors, which target programmed cell death protein 1 (PD-1) pathways, have recently emerged as a potent therapeutic option. The present report presents the Israeli experience with PD-1 inhibitors for the treatment of loco-regionally advanced or metastatic cSCC in a diverse and elderly population, with or without the addition of radiotherapy.

Material and methods

The databases of two university medical centers were retrospectively searched for patients with cSCC treated with the PD-1 inhibitors cemiplimab or pembrolizumab between January 2019 and May 2022. Data on baseline, disease-related, treatment-related, and outcome parameters were collected and analyzed.

Results

The cohort included 102 patients of a median age 78.5 years. Evaluable response data were available for 93. The overall response rate was 80.6%: complete response in 42 patients (45.2%) and partial response in 33 (35.5%). Stable disease was recorded in 7 (7.5%) and progressive disease in 11 (11.8%). Median progression-free survival was 29.5 months. Radiotherapy was administered to the target lesion during PD-1 treatment in 22.5% of patients. mPFS was not significantly different in patients who treated with RT than patients how did not (NR vs 18.4 months, HR=0.93, 95%CI: 0.39 - 2.17, p<0.859). Any-grade toxicity was recorded in 57 patients (55%), including grade ‗3 in 25, of whom 5 (5% of cohort) died. Compared to toxicity-free patients, patients with drug toxicity had better progression-free survival (18.4 months vs not reached, HR=0.33, 95% CI: 0.13-0.82, p=0.012) and higher overall response rate (87% vs 71.8%, p=0.06).

Conclusion

This retrospective real-world study showed that PD-1 inhibitors were effective in the treatment of locally advanced or metastatic cSCC and appeared to be amenable for use in elderly or fragile patients with comorbidities. However, the high toxicity warrants consideration against other modalities. Induction or consolidation radiotherapy may improve the results. These findings need to be corroborated in a prospective trial.

Evaluation of sun-protective behaviors in transplant clinic patients: a longitudinal analysis

Organ transplant recipients (OTRs) are at a significantly elevated risk for developing cutaneous malignancies. In recent years, the advent of dermatology clinics dedicated to this specific patient population has aimed to provide increased access and specialized care, including important sun-protective behavior education. It has been shown that OTRs tend to have poor sun-protective practices, and care at these specialized dermatology clinics has facilitated an improvement in sun-protective behavior. Previously, sun-protective behavior of patients within these specialized clinics has been characterized longitudinally, though only for a short duration of 3 months. We retrospectively analyzed a cohort of 230 OTRs seen at a single academic institution's transplant clinic between 2016-2020 and sought to characterize sun-protective behavior at baseline and longitudinally. 78 patients returned for at least one follow-up visit, and the median follow-up duration was 15.1 months (IQR 8.4-24.3 months). Sun-protective behavior was quantified using the average score of questions addressing sunscreen usage frequency, consistency, circumstance of application, reapplication, and sun avoidance. We utilized paired Wilcoxon signed-rank tests to analyze changes in sun-protective behavior between initial visits and subsequent follow-up visits. Sun-protective behavior was increased at the first follow-up visit (median change in sun-protective score - 0.04, p = 0.017) and second follow-up visit (median change in sun-protective score - 0.25, p = 0.026) compared to the initial visit. Multivariable logistic regression and mixed effects modeling were employed to quantify patient features associated with increased sun-protective behavior. Female sex [OR 3.79, 95% CI (1.83, 8.04)] and personal history of skin cancer [OR 3.06, 95% CI (1.25, 7.76)] were associated with stronger sun-protective behaviors at baseline. Female sex [OR 13.77, 95% CI (2.44, 77.52)] was the only characteristic associated with increased sun-protective behavior over time. Our findings identify patient characteristics that are associated with increased sun-protective behavior after education in a dermatology clinic dedicated to OTRs.

Skin cancer in solid organ transplant recipients: still an open problem

In the last two decades, the optimization of organ preservation and surgical techniques, and the personalized immunosuppression have reduced the rate of acute rejections and early post-transplant complications. However, long-term graft survival rates have not improved over time, and evidence suggest a role of chronic calcineurin inhibitor toxicity in this failure. Solid organ transplant recipients may develop chronic dysfunction/damage and several comorbidities, including post-transplant malignancies. Skin cancers, mostly non-melanoma skin cancers (squamous cell carcinoma and basal cell carcinoma), are the most common malignancies in Caucasian solid organ transplant recipients. Several factors, together with immunosuppression, may contribute to the susceptibility for skin cancers which, although often treatable, could be associated with a much higher mortality rate than in the general population. The rapid identification and treatment (including reduction of immunosuppression and early surgical treatments) have an important role to avoid an aggressive behavior of these malignancies. Organ transplant recipients with a history of skin cancer should be followed closely for developing new and metastatic lesions. Additionally, patient education on the daily use of sun-protective measures and the recognition of the early signs (self-diagnosis) of coetaneous malignancies are useful preventive measures. Finally, clinicians should make themselves aware of the problem and build, in every clinical follow-up center, collaborative network involving transplant clinicians, dermatologists and surgeons who should work together to easily identify and rapidly treat these complications. In this review, we discuss the current literature regarding the epidemiology, risk factors, diagnosis, preventive strategies and treatments of skin cancer in organ transplantation.

The Use of Retinoids for the Prevention and Treatment of Skin Cancers: An Updated Review

Retinoids are natural and synthetic vitamin A derivatives that are effective for the prevention and the treatment of non-melanoma skin cancers (NMSC). NMSCs constitute a heterogenous group of non-melanocyte-derived skin cancers that impose substantial burdens on patients and healthcare systems. They include entities such as basal cell carcinoma and cutaneous squamous cell carcinoma (collectively called keratinocyte carcinomas), cutaneous lymphomas and Kaposi’s sarcoma among others. The retinoid signaling pathway plays influential roles in skin physiology and pathology. These compounds regulate diverse biological processes within the skin, including proliferation, differentiation, angiogenesis and immune regulation. Collectively, retinoids can suppress skin carcinogenesis. Both topical and systemic retinoids have been investigated in clinical trials as NMSC prophylactics and treatments. Desirable efficacy and tolerability in clinical trials have prompted health regulatory bodies to approve the use of retinoids for NMSC management. Acceptable off-label uses of these compounds as drugs for skin cancers are also described. This review is a comprehensive outline on the biochemistry of retinoids, their activities in the skin, their effects on cancer cells and their adoption in clinical practice.

The Immunohistochemical Assessment of Neoangiogenesis Factors in Squamous Cell Carcinomas and Their Precursors in the Skin

Cutaneous squamous cell carcinoma (cSCC) is a common skin cancer. Well-limited forms can be easily treated with excision, but locally advanced cancers can, unfortunately, progress to metastasis. However, it is difficult to establish the prognosis for cutaneous squamous cell carcinoma and its potential to metastasize. Therefore, this study aimed to evaluate neoangiogenesis in cSCC, as it plays a major role in the dissemination of neoplasia. A literature review was performed on selected neoangiogenic factors (VEGF, ANG1/2, Notch1, CD31/34/105, EGF, etc.). Most of them, including VEGF, EGFR, and CD105, had more elevated levels in the advanced stages of the lesion. The same is true for Notch1, p53, and TGFβ, which are the most frequently mutated tumor suppressors in this type of skin cancer. In addition, the inhibition of some of these markers, using Ang1 analogs, inhibitors of EGFR, TRAF6, or combined inhibitors of EGFR and IGF-IR, may lead to a decrease in tumor size. In conclusion, this literature review identified diagnostic and prognostic markers, as well as possible factors that can be used for the targeted therapy of spinaliomas.

Advances in Cutaneous Squamous Cell Carcinoma Management

Simple Summary

Cutaneous squamous cell carcinoma (cSCC) is an increasingly prevalent and morbid cancer worldwide. Management of this cancer has changed significantly in the last decade through improved risk stratification and new therapies offering patients with locally advanced and metastatic disease more effective, less toxic, and more durable treatment options. Ongoing clinical trials are assessing new therapeutic options as well as optimizing existing regimens in efforts to better manage this cancer. The recent developments highlight the need for multidisciplinary care, especially for those with locally advanced and metastatic disease.

Abstract

cSCC is increasing in prevalence due to increased lifespans and improvements in survival for conditions that increase the risk of cSCC. The absolute mortality of cSCC exceeds melanoma in the United States and approaches that of melanoma worldwide. This review presents significant changes in the management of cSCC, focusing on improvements in risk stratification, new treatment options, optimization of existing treatments, and prevention strategies. One major breakthrough in cSCC treatment is the advent of immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1), which have ushered in a renaissance in the treatment of patients with locally advanced and metastatic disease. These agents have offered patients with advanced disease decreased therapeutic toxicity compared to traditional chemotherapy agents, a more durable response after discontinuation, and improved survival. cSCC is an active field of research, and this review will highlight some of the novel and more developed clinical trials that are likely to impact cSCC management in the near future.

Lethal Dermal Sarcoma in Immunosuppressed Patients

Skin cancer is the leading malignancy in immunosuppressed patients, including organ transplant recipients (OTRs), which is increasing in incidence as OTRs live longer. We performed a single-center case series of 4 patients with scalp pleomorphic dermal sarcoma and a history of multiple keratinocyte carcinomas. Outcomes included incidence of dermal sarcoma, dermal sarcoma-related mortality, and histopathologic findings. Out of more than 200 patients followed over a 3-year period in Massachusetts General Hospital High Risk Skin Cancer Clinics, all skin cancer-related deaths (2/2) were due to metastatic dermal sarcoma. Three of 4 patients diagnosed with scalp dermal sarcoma were OTRs and had been on at least one immunosuppressive medication for a median of 9 years. For patients who died from dermal sarcoma, the median time between diagnosis and death was 6 months. Our findings suggest pleomorphic dermal sarcoma contributes to skin cancer-related morbidity and mortality in OTRs.

Mammalian Target of Rapamycin Inhibitors for prolonged secondary prevention of non-melanoma skin cancer in solid organ transplant recipients

BACKGROUND

Immunosuppressive agents are essential for graft survival in solid-organ transplant recipients (SOTRs), but they have substantial durable side effects, including a higher incidence of aggressive non-melanoma skin cancers (NMSCs). Hitherto, only one class of immunosuppressants, mammalian target of rapamycin inhibitors (mTORi), may inhibit skin tumor formation, however their durable effectiveness is controversial.

OBJECTIVE

To evaluate the sustained effectiveness of mTORi in reducing NMSCs' incidence in SOTRs.

METHODS

A retrospective study was conducted in a specialized dermatology clinic for SOTRs of a tertiary university-affiliated medical center. SOTRs with a history of at least one histologically proven NMSC, were followed for 6 years: 3 years after transplantation, before initiation of mTORi, and 3 years under mTORi treatment.

RESULTS

The cohort consisted of 44 SOTRs. Treatment with mTORi was initiated on average 6.27 (3.34-6.34) years following transplantation. In the 3 years before mTORi treatment initiation, the mean number of new NMSCs per patient was 2.11 (1-14). This value decreased to 1.2 (0-19) in the 3 years under mTORi treatment (P=0.0007). Analysis by NMSC type yielded a significant decrease in both SCCs and BCCs.

CONCLUSION

This study found that mTORi are effective for prolonged secondary prevention of NMSCs in SOTRs. This article is protected by copyright. All rights reserved.

Pathways from Diagnosis to Death from Keratinocyte Cancer in Kidney Transplant Recipients

BACKGROUND

Kidney transplant recipients are at increased risk of developing and dying from keratinocyte cancer. We aimed to describe the clinical course of keratinocyte cancer-related deaths in a cohort of kidney transplant recipients.

METHODS

In kidney transplant recipients transplanted between 1995 and 2014 in Queensland, Australia, we ascertained keratinocyte cancer deaths by searching national transplant and state death registries to March 2020. Deceased transplant recipients' medical records were reviewed to assess features of the primary lesion of the fatal keratinocyte cancer, metastases, and clinical information before death.

RESULTS

Of 658 kidney transplant recipient deaths, 49 (7%) were due to keratinocyte cancer, and medical records were available for 36 (73%). One death was due to basal cell carcinoma, and 35 were from squamous cell carcinoma (SCC), primarily from the head and neck (24; 69%). The most common site of metastasis was the lungs (21; 58%). Median time (minimum, maximum) from the diagnosis of primary SCC to metastasis was 5 months (0, 29). After this, the median time to death was 9 months (1, 50).

CONCLUSION

Fatal keratinocyte cancers overwhelmingly arise on the head and neck, with lungs the most common metastasis site. The short time from diagnosis of primary to death indicates the aggressive nature of these keratinocyte cancers.

Das kutane Plattenepithelkarzinom – ein Update

Hintergrund Das kutane Plattenepithelkarzinom (PEK) ist nach dem Basalzellkarzinom der zweithäufigste bösartige Hauttumor. In Deutschland wurden 2014 über 50.000 PEK-Neuerkrankungen dokumentiert. Mit Zunahme der durchschnittlichen Lebenserwartung und Komorbiditäten treten mittlerweile auch gehäuft lokal fortgeschrittene Tumore mit Metastasierung auf.

Methode Selektive Literaturrecherche in PubMed und unter Berücksichtigung der deutschen S3-Leitlinien „Aktinische Keratosen und Plattenepithelkarzinom der Haut“ und „Prävention von Hautkrebs“.

Ergebnisse Beim PEK ist der Goldstandard die vollständige Exzision des Primärtumors mittels histopathologischer Kontrolle der Schnittränder. Eine Radiotherapie kann eingesetzt werden, wenn eine vollständige Exzision nicht erreicht werden kann bzw. Inoperabilität besteht. Im Falle eines metastasierten (mPEK) oder lokal fortgeschrittenen (laPEK) PEK, welches nicht kurativ operiert oder bestrahlt werden kann, werden systemische medikamentöse Therapien eingesetzt. Mit der Zulassung des PD1-Antikörpers Cemiplimab steht seit 2019 in der EU eine neue systemische Therapie zur Behandlung des fortgeschrittenen PEK zur Verfügung. Nach bis zu 3 Jahren Follow-up sprechen noch 46% der Patienten mit mPEK und laPEK auf Cemiplimab an, der Medianwert für das Gesamtüberleben und die Ansprechdauer ist in beiden Gruppe noch nicht erreicht. Weitere Antikörper gegen PD1 oder PDL1, Kombinationstherapien sowie die Immuntherapie mit onkolytischen Viren ermöglichen zahlreiche Therapieoptionen und sind aktuell Gegenstand der Forschung.

Schlussfolgerung Mit der Zunahme von fortgeschrittenen Stadien des PEK nimmt die Wichtigkeit des interdisziplinären Tumorboards für den Therapieentscheid immer mehr zu. Die Weiterentwicklung bestehender therapeutischer Konzepte, die Identifikation von gut wirksamen Kombinationstherapien sowie die Entwicklung weiterer verträglicher zielgerichteter Systemtherapien ist eine entscheidende dermatoonkologische Herausforderung der nächsten Jahre.

Ablative Fractional Laser-assisted Low-irradiance Photodynamic Therapy for Treatment of Actinic Keratoses in Organ Transplant Recipients: A Prospective, Randomized, Intraindividual Controlled Trial

Pain and inferior efficacy are major limiting factors of conventional photodynamic therapy for the field treatment of actinic keratoses in immunosuppressed organ transplant recipients. This prospective randomized controlled study evaluates the efficacy and tolerability of ablative fractional laser system pretreatment combined with low-irradiance photodynamic therapy (18.5 mW/cm2) compared with conventional photodynamic therapy (61.67 mW/cm2) in the treatment of actinic keratoses on the face and scalp in organ transplant recipients, using a red light-emitting diode lamp at a total light dose of 37 J/cm2. Low-irradiance photodynamic therapy combined with Er:YAG pretreatment achieved a significantly superior lesion response rate (mean ± standard deviation 77.3 ± 23.6%) compared with conventional photodynamic therapy (61.8 ± 21.4%; p = 0.025) in intra-individual fields at 3 months without negatively impacting pain (p = 0.777) or cosmetic outcome (p = 0.157).

Covering of large scalp defects prior to postoperative irradiation

BACKGROUND AND OBJECTIVE

After R0 resection of extensive cutaneous squamous cell carcinoma of the scalp with indication for postoperative radiotherapy, closure techniques should be chosen that allow rapid initiation of radiotherapy. The aim of this retrospective analysis is to evaluate defect coverage by transverse transposition flap and split skin grafting of the donor site in such a scenario with regard to oncologic safety (recurrence rate) and permanence of wound closure.

PATIENTS AND METHODS

Eleven patients were identified who had histologic cutaneous squamous cell carcinoma treated by microscopically controlled excision and defect coverage using a transverse transposition flap and split skin grafting of the donor site and who received postoperative radiotherapy. Patients were evaluated for recurrence, wound healing disorders and side effects of radiotherapy.

RESULTS

The mean age was 81 years. Follow-up time averaged 1.4 years after the last radiotherapy session. Wound healing disorders of the transposition flap or graft necrosis were not detected. All therapy-associated side effects had resolved at follow-up. Local recurrence or metastasis did not occur.

CONCLUSIONS

Combined transverse transposition flap plasty with split-skin grafting of the donor site is a safe treatment concept with few side effects for large scalp defects with exposed calvaria requiring postoperative radiotherapy.

A long-term cohort study of acitretin for prevention of keratinocyte carcinoma in solid organ transplant recipients

Background

Solid organ transplant recipients (SOTR) are at high risk of keratinocyte carcinoma (KC). Long‐term evidence for acitretin as chemoprophylaxis in this population is lacking.

Objective

To determine the benefit of long‐term acitretin for KC chemoprevention in SOTR.

Methods

A retrospective cohort study of SOTR treated with acitretin at an Australian transplant dermatology clinic was performed. General estimating equations were used to evaluate change in rates of histologically confirmed KC in the 6–12 months prior to acitretin and following a minimum 6 months of treatment. A control group of patients within the same service was included, comprising SOTR who were not treated with acitretin.

Results

Twenty‐two patients received acitretin treatment for at least 6 months, eighteen for at least 5 years and four for at least 9 years. The median KC rate pretreatment was 3.31 per year (IQR 1.93, 5.40). There was a significant reduction in the rate of KC in the first year of acitretin treatment (IRR 0.41, 95% CI 0.22, 0.76, P = 0.005), and this effect was observed for 5 years (IRR at 5 years 0.34, 95% CI 0.17, 0.67, P = 0.002). The control group had no statistically significant change in KC rate over time in the study.

Conclusions

Acitretin appears to be well‐tolerated and effective in reducing KC in SOTR for at least 5 years. Study limitations include its retrospective nature, small sample size and lack of blinding.

Cutaneous squamous cell carcinoma arising in immunosuppressed patients: a systematic review of tumor profiling studies

As solid organ transplantation becomes more prevalent, more individuals are living as members of the immunosuppressed population with an elevated risk for cutaneous squamous cell carcinoma (cSCC). Although great progress has been made in understanding the pathogenesis of cSCC in general, little is known about the drivers of tumorigenesis in immunosuppressed patients and organ-transplant recipients, specifically. This systematic review sought to synthesize information regarding the genetic and epigenetic alterations as well as changes in protein and mRNA expression that place this growing population at risk for cSCC, influence treatment response, and promote tumor aggressiveness. This review will provide investigators with a framework to identify future areas of investigation and clinicians with additional insight into how to best manage these patients.

Second primary malignancies in chronic lymphocytic leukaemia: Skin, solid organ, haematological and Richter's syndrome

Chronic lymphocytic leukaemia (CLL) is invariably accompanied by some degree of immune failure, and CLL patients have a high rate of second primary malignancy (SPM) compared to the general population. We comprehensively documented the incidence of all forms of SPM including skin cancer (SC), solid organ malignancy (SOM), second haematological malignancy (SHM) and separately Richter's syndrome (RS) across all therapy eras. Among the 517 CLL/small lymphocytic lymphoma (SLL) patients, the overall incidence of SPMs with competing risks was SC 31.07%, SOM 25.99%, SHM 5.19% and RS 7.55%. Of the 216 treated patients, 106 (49.1%) had at least one form of SPM, and 63 of 106 (29.2% of treated patients) developed an SPM 1.5 years (median) after treatment for their CLL. Melanoma accounted for 30.3% of SC. Squamous cell carcinoma (SCC), including eight metastatic SCCs, was 1.8 times more than basal cell carcinoma (BCC), a reversal of the typical BCC:SCC ratio. The most common SOMs were prostate (6.4%) and breast (4.5%). SHM included seven acute myeloid leukaemia (AML) and five myelodysplasia (MDS) of which eight (four AML, four MDS) were therapy-related. Any SPM occurred in 32.1% of 53 Monoclonal B-lymphocytosis (MBL) patients. Age-adjusted standardised rates of SPM (per 100,000) for CLL, MBL and the general Australian population were 2648, 1855 and 486.9, respectively. SPMs are a major health burden with 44.9% of CLL patients with having at least one SPM, and apart from SC, associated with significantly reduced overall survival. Dramatic improvements in CLL treatment and survival have occurred with immunochemotherapy and targeted therapies, but mitigating SPM burden will be important to sustain further progress.

Outcomes of skin cancers in pediatric solid organ transplant patients: A systematic review

BACKGROUND

The most frequently reported malignancies after solid organ transplant are cutaneous, but data on the risk in pediatric populations varies across studies.

OBJECTIVES

To perform a systematic review including reported features and outcomes of skin cancers in pediatric solid organ transplant recipients.

METHODS

EMBASE and MEDLINE were systematically searched (Prospero CRD42020201659).

RESULTS

The review summarizes data from 20 studies on 337 patients, with a median age ranging from 15.0 to 19.5 years as reported in 4 studies, who developed skin malignancies after pediatric solid organ transplantation. Median ages at transplant and skin cancer diagnosis ranged from 1.5 to 17.0 years and 15.3 to 33.5 years, respectively. Squamous cell carcinoma (SCC) was most commonly reported (218 cases), followed by basal cell carcinoma (BCC) (91 cases), melanoma (18 cases), and unspecified keratinocyte carcinomas (2 cases). The median latency period between transplantation and cancer diagnosis ranged from 2.2 to 21.0 years. Overall, 4 studies reported 17 cases of metastasis in total, and recurrence was reported in one case. Six deaths were reported in one study related to SCC and melanoma metastases. The incidence rate of skin cancer after pediatric transplantation per 100 person-years of follow-up was 2.1 based on 5 studies.

CONCLUSION

The most frequent post-transplant malignancy in pediatric organ transplant recipients was SCC.

Risk factors and prevention strategies for cutaneous squamous cell carcinoma in transplant recipients

It has been well established that organ transplant recipients (OTRs) are at an increased risk of skin cancer. Studies vary on the exact degree of this risk, but it is likely somewhere between 60 and 100 times more likely that an OTR patient will develop skin cancer. The management of skin cancer burden in OTRs requires a multidisciplinary approach with the transplant team, dermatologists, and oncology. In many major hospital systems, there are dedicated transplant dermatology clinics that allow for specialized and more frequent screenings of this high-risk population. Here we discuss the pathogenesis, presentation, and treatment options used by dermatologists to prevent and treat commonly found skin cancers in this vulnerable population.

Long-Term Risk of Skin Cancer and Lymphoma in Users of Topical Tacrolimus and Pimecrolimus: Final Results from the Extension of the Cohort Study Protopic Joint European Longitudinal Lymphoma and Skin Cancer Evaluation (JOELLE)

Purpose

Evidence is insufficient to infer whether topical calcineurin inhibitors (TCIs; tacrolimus and pimecrolimus) cause malignancy. The study objective was to estimate the long-term risk of skin cancer and lymphoma associated with topical TCI use in adults and children, separately.

Patients and Methods

A cohort study in Denmark, Sweden, UK, and the Netherlands was conducted. Adjusted incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated for nonmelanoma skin cancer (NMSC), melanoma, cutaneous T-cell lymphoma (CTCL), non-Hodgkin lymphoma (NHL) excluding CTCL, and Hodgkin lymphoma (HL) in new users of TCIs versus users of moderate/high-potency topical corticosteroids.

Results

The study included 126,908/61,841 adults and 32,605/27,961 children initiating treatment with tacrolimus/pimecrolimus, respectively. Follow-up was ≥10 years for 19% of adults and 32% of children. Incidence rate ratios and (95% confidence intervals) for tacrolimus versus corticosteroid users in adults were <1 for melanoma, non-Hodgkin lymphoma, and Hodgkin lymphoma; and 1.80 (1.25–2.58) for cutaneous T-cell lymphoma. For pimecrolimus, IRRs in adults were <1 for non-Hodgkin lymphoma, cutaneous T-cell lymphoma, and Hodgkin’s lymphoma; and 1.21 (1.03–1.41) for melanoma; and 1.28 (1.20–1.35) for nonmelanoma skin cancer. In children, results were inconclusive due to few events. In adults, incidence rate ratios ≥5 years after first topical calcineurin inhibitor exposure were not higher than in overall analyses.

Conclusion

Overall, we found little evidence associating use of topical calcineurin inhibitors with skin cancer and lymphoma; confounding by indication, surveillance bias, and reverse causation may have influenced these results. Even if causal, the public health impact of these excess risks would be low and confined to the first years of exposure.

Immunotherapy and Systemic Treatment of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinomas (cSCC) represent one of the most diagnosed non-melanoma skin cancers and its incidence is increasing globally. Whereas early stage and low risk cSCC is typically treated with surgery, and in some cases other localized therapeutic modalities, locally advanced or metastatic cSCC is a cause of significant morbidity and mortality that requires a different approach to therapy. Therapeutic attempts at treating advanced cSCC include a multi-disciplinary approach with considerations for surgery, radiation, and systemic therapies. In this review, we will discuss the various systemic therapies that have been trialed for advanced cSCC, beginning with the early cytotoxic and platinum-based agents as well as their corresponding limitations. We will then review the targeted approaches using EGFR inhibitors prior to discussing the more recent immunotherapeutics that have shown good tumor responses in this often-lethal disease.

Cumulative incidence and disease-specific survival of metastatic cutaneous squamous cell carcinoma: A nationwide cancer registry study

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) represents the most serious form of keratinocyte cancers because of its metastatic potential. Studies on nationwide incidence and disease-specific survival rates of metastatic cSCC (mcSCC) are lacking.

OBJECTIVE

To investigate the cumulative incidence and disease-specific survival of patients with mcSCC in the Dutch population and assess patient-based risk factors.

METHODS

We conducted a nationwide cancer registry study including all patients with the first cSCC in 2007 or 2008, using data from the Netherlands Cancer Registry, the nationwide network and registry of histopathology and cytopathology, and Statistics Netherlands. Cumulative incidence and Kaplan-Meier curves were calculated, and time-dependent Cox proportional hazards regression analyses were used.

RESULTS

Of the 11,137 patients, metastases developed in 1.9% (n = 217). The median time to metastasis was 1.5 years (interquartile range 0.6-3.8 years). The risk factors were age (adjusted hazard ratio [aHR] 1.03, 95% CI 1.02-1.05), male sex (aHR 1.7, 95% CI 1.3-2.3), and immunosuppression (aHR [organ transplant recipient] 5.0, 95% CI 2.5-10.0; aHR [hematologic malignancy] 2.7, 95% CI 1.6-4.6). The 5-year disease-specific survival for patients with mcSCC was 79.1%.

LIMITATIONS

Only histopathologically confirmed mcSCCs were included.

CONCLUSION

About 2% of cSCCs metastasize, with higher risk for men, increasing age, and immunocompromised patients. Disease-specific survival for patients with mcSCC is high.

Treatment of advanced cutaneous squamous cell carcinoma: a Mohs surgery and dermatologic oncology perspective

Locally advanced or metastatic cutaneous squamous cell carcinoma no longer amenable to surgical resection or primary radiation therapy requires an alternative approach to treatment. Until 2018, management consisted of limited systemic chemotherapies, which carried marginal clinical benefit. The introduction of immunotherapy with anti-PD-1 antibodies resulted in alternative treatment options for advanced cutaneous squamous cell carcinoma with substantial antitumor activity, durable response and acceptable safety profile. The field of immunotherapeutics continues to expand with adjuvant, neoadjuvant and intralesional studies currently in progress. Herein, the authors discuss their approach for the treatment of advanced cutaneous squamous cell carcinoma from the perspective of a Mohs surgeon and a dermatologic oncologist.

Cutaneous Malignancies After Kidney and Simultaneous Pancreas-Kidney Transplantations

BACKGROUND

Organ transplant recipients are at increased risk of nonmelanotic skin cancers (NMSC). Scarce data exist regarding secondary malignancies developing post-simultaneous pancreas-kidney (SPK) transplantations. Our aim was to assess long-term risk of skin cancers among kidney alone (KA) and SPK transplantation recipients.

METHODS

In this study, 521 patients who underwent KA or SPK transplantation at our medical center were observed up by dedicated nephrologists and dermatologists. SPK transplantation recipients were matched with a control group of KA transplantation recipients based on demographic and clinical data. A multivariate analysis was performed to find independent cancer risk factors.

RESULTS

Patients who developed skin cancer were generally older, had a fair skin type, and had a higher incidence of NMSC before transplantation. Older age and fair skin type were independent risk factors on multivariate analysis. SPK transplantation in itself was not an independent risk factor. Cancer recurrence was associated with older age and male sex. Darker skin type and lowered immunosuppressive burden were protective.

CONCLUSION

In contrast to previous studies, the use of antithymocytic agents or SPK transplantation were not independently associated with increased skin cancer risk in this multivariate analysis. These findings emphasize the complex interplay between posttransplantation NMSC and various clinical and epidemiologic risk parameters.

Antibody-Based Targeted Interventions for the Diagnosis and Treatment of Skin Cancers

BACKGROUND

Cutaneous malignancies most commonly arise from skin epidermal cells. These cancers may rapidly progress from benign to a metastatic phase. Surgical resection represents the gold standard therapeutic treatment of non-metastatic skin cancer while chemo- and/or radiotherapy are often used against metastatic tumors. However, these therapeutic treatments are limited by the development of resistance and toxic side effects, resulting from the passive accumulation of cytotoxic drugs within healthy cells.

OBJECTIVE

This review aims to elucidate how the use of monoclonal Antibodies (mAbs) targeting specific Tumor Associated Antigens (TAAs) is paving the way to improved treatment. These mAbs are used as therapeutic or diagnostic carriers that can specifically deliver cytotoxic molecules, fluorophores or radiolabels to cancer cells that overexpress specific target antigens.

RESULTS

mAbs raised against TAAs are widely in use for e.g. differential diagnosis, prognosis and therapy of skin cancers. Antibody-Drug Conjugates (ADCs) particularly show remarkable potential. The safest ADCs reported to date use non-toxic photo-activatable Photosensitizers (PSs), allowing targeted Photodynamic Therapy (PDT) resulting in targeted delivery of PS into cancer cells and selective killing after light activation without harming the normal cell population. The use of near-infrared-emitting PSs enables both diagnostic and therapeutic applications upon light activation at the specific wavelengths.

CONCLUSION

Antibody-based approaches are presenting an array of opportunities to complement and improve current methods employed for skin cancer diagnosis and treatment.

Keratinocyte Cancer Mortality in Kidney Transplant Recipients

BACKGROUND

Kidney transplant recipients are at increased risk of developing and dying from keratinocyte cancer. Risk factors for keratinocyte cancer death have not been previously described.

METHODS

In a cohort of kidney transplant recipients transplanted in Queensland 1995-2014, we identified keratinocyte cancer deaths by searching national transplant and state death registries to March 2020. Standardized keratinocyte cancer mortality rates and mortality ratios were calculated. We used a competing risks model to identify factors associated with keratinocyte cancer death and calculated relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

There were 562 deaths in 1866 kidney transplant recipients (62% males; 86% Caucasian) with 25 934 person-years of follow-up, of which 36 were due to squamous cell carcinoma (SCC) and 1 to basal cell carcinoma (BCC) with standardized mortality rates of 78 (95% CI 53-111) and 2 (95% CI 0.1-11) per 100,000 person-years respectively. The standardized mortality ratio for keratinocyte cancer was 23 (95% CI 23-24). Besides Caucasian ethnicity (associated with 100% of keratinocyte cancer deaths), male sex (RR 3.24 95% CI 1.26-8.33), and older age at transplantation (≥ 50 versus <50 years RR 3.09 95% CI 1.38-6.89) were associated with increased risk of keratinocyte cancer death.

CONCLUSIONS

Keratinocyte cancer mortality in kidney transplant recipients is over 20 times higher than in the general population. Most keratinocyte cancer deaths are due to cutaneous SCC, however, BCC can be fatal. Education in skin cancer prevention is essential to avoid unnecessary deaths from keratinocyte cancer amongst kidney transplant recipients.

Association Between Topical Calcineurin Inhibitor Use and Keratinocyte Carcinoma Risk Among Adults With Atopic Dermatitis

Importance

Topical calcineurin inhibitors (TCIs), primarily used to treat atopic dermatitis (AD), carry a black box label warning users about the potential for increased skin cancer risk. The risk associated with keratinocyte carcinoma (KC), the most common cancer, defined as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), remains poorly defined because findings from large-scale postmarketing surveillance studies have not been reported.

Objectives

To examine KC risk overall and by subtype (BCC and SCC) among adults with AD exposed to TCIs compared with those exposed to topical corticosteroids (primary comparator group) and those unexposed to TCIs or topical corticosteroids (alternative comparator group) as well as alterations in risk with TCI dose, frequency, and duration of exposure.

Design, Setting, and Participants

A retrospective cohort study was conducted at Kaiser Permanente Northern California, a large, integrated health care delivery system, of adults 40 years or older (n = 93 746) with a physician-rendered diagnosis of AD or dermatitis. Patients who were diagnosed from January 1, 2002, to December 31, 2013, were included, with follow-up through December 31, 2017. Data analysis was conducted from June 1, 2016, to October 1, 2018.

Exposures

Time-varying pharmacy-dispensed TCI exposure (n = 7033) over the study period was compared with topical corticosteroids (n = 73 674) and no TCI or topical corticosteroid exposure (n = 46 141).

Main Outcomes and Measures

Electronic pathologic testing-validated incident KCs (n = 7744).

Results

Among a cohort of 93 746 members, the mean (SD) age was 58.5 (12.7) years, and 55 023 patients (58.7%) were women. Multivariable Cox proportional hazards regression revealed no association between TCI exposure and KC risk (adjusted hazard ratio [aHR], 1.02; 95% CI, 0.93-1.13) compared with topical corticosteroid exposure. Similarly, there were no significant differences in BCC risk (aHR, 1.01; 95% CI, 0.90-1.14, TCI vs topical corticosteroids) or SCC risk (aHR, 0.94; 95% CI, 0.82-1.08, TCI vs topical corticosteroids). Changing the comparator group to unexposed individuals yielded similar findings (aHR, 1.04; 95% CI, 0.91-1.19, TCI vs unexposed for basal cell carcinoma). There were no associations between TCI dose, frequency, and duration of use and BCC, SCC, or overall KC risk.

Conclusions and Relevance

The results of this postmarketing surveillance study of adult health plan members with AD revealed no apparent association between TCI exposure and overall KC, BCC, or SCC risk. Secondary analyses examining dose, frequency, and duration of TCI exposure revealed no associations. These findings suggest that use of TCIs may be safe with respect to KC risk among adults with AD.

Clinically relevant aberrant Filip1l DNA methylation detected in a murine model of cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinomas (cSCC) are among the most common and highly mutated human malignancies. Understanding the impact of DNA methylation in cSCC may provide avenues for new therapeutic strategies.

METHODS

We used reduced-representation bisulfite sequencing for DNA methylation analysis of murine cSCC. Differential methylation was assessed at the CpG level using limma. Next, we compared with human cSCC Infinium HumanMethylation BeadArray data. Genes were considered to be of major relevance when they featured at least one significantly differentially methylated CpGs (RRBS) / probes (Infinium) with at least a 30% difference between tumour vs. control in both a murine gene and its human orthologue. The human EPIC Infinium data were used to distinguish two cSCC subtypes, stem-cell-like and keratinocyte-like tumours.

FINDINGS

We found increased average methylation in mouse cSCC (by 12.8%, p = 0.0011) as well as in stem-cell like (by 3.1%, p=0.002), but not keratinocyte-like (0.2%, p = 0.98), human cSCC. Comparison of differentially methylated genes revealed striking similarities between human and mouse cSCC. Locus specific methylation changes in mouse cSCC often occurred in regions of potential regulatory function, including enhancers and promoters. A key differentially methylated region was located in a potential enhancer of the tumour suppressor gene Filip1l and its expression was reduced in mouse tumours. Moreover, the FILIP1L locus showed hypermethylation in human cSCC and lower expression in human cSCC cell lines.

INTERPRETATION

Deregulation of DNA methylation is an important feature of murine and human cSCC that likely contributes to silencing of tumour suppressor genes, as shown for Filip1l.

FUNDING

British Skin Foundation, Cancer Research UK.

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.