The pathogenesis of cutaneous squamous cell carcinoma in organ transplant recipients

Dermatology-oncolog

Evaluation of a Novel Broad-Spectrum PCR-Multiplex Genotyping Assay for Identification of Cutaneous Wart-Associated Human Papillomavirus Types

A large number of human papillomavirus (HPV) types, distributed over five papillomavirus genera, are detectable in the skin. HPV types belonging to the alpha, gamma, and mu genera have been detected in cutaneous warts. A state-of-the-art HPV genotyping assay for these cutaneous wart-associated HPV types does not exist although warts constitute a highly prevalent skin condition, especially in children (33%) and organ transplant recipients (45%). Cutaneous warts are again the focus of attention as their clinical relevance rises with the increasing number of chronically immunosuppressed patients. The objective of this study was to develop and evaluate a DNA-based genotyping system for all known cutaneous wart-related HPV types using PCR and Luminex xMAP technology. The broad-spectrum PCR amplified DNA of all known wart-associated HPV types from the genera alpha (HPVs 2, 3, 7, 10, 27, 28, 29, 40, 43, 57, 77, 91, and 94), gamma (HPVs 4, 65, 95, 48, 50, 60, and 88), mu (HPVs 1 and 63), and nu (HPV41). The probes were evaluated using plasmid HPV DNA and a panel of 45 previously characterized cutaneous wart biopsy specimens showing high specificity. HPV was also identified in 96% of 100 swabs from nongenital cutaneous warts. HPV types 1, 2, 27, and 57 were the most prevalent HPV types detected in 89% of the swabs. In conclusion, this Luminex-based genotyping system identifies all known cutaneous wart HPV types including phylogenetically related types, is highly HPV type specific, and is suitable for large-scale epidemiological studies.Minor Ailment

Organ transplantation and cutaneous squamous cell carcinoma: progress, pitfalls and priorities in immunosuppression-associated keratinocyte carcinoma

Dermatology-oncolog

Organ transplantation and cutaneous squamous cell carcinoma: progress, pitfalls and priorities in immunosuppression‐associated keratinocyte carcinoma

Dermatology-oncolog

Metastatic cutaneous squamous cell carcinoma shows frequent deletion in the protein tyrosine phosphatase receptor Type D gene

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of nonmelanoma skin cancer (NMSC), and its incidence is increasing rapidly. Metastatic cSCC accounts for the majority of deaths associated with NMSC, but the genetic basis for cSCC progression remains poorly understood. A previous study identified small deletions (typically <1 Mb) in the protein tyrosine phosphatase receptor Type D (PTPRD) gene that segregated with more aggressive cSCC. To investigate the apparent association between deletion within PTPRD and cSCC metastasis, a series of 74 formalin-fixed paraffin-embedded tumors from 31 patients was analyzed using a custom Illumina 384 SNP microarray. Deletions were found in 37% of patients with metastatic cSCC and were strongly associated with metastatic tumors when compared to those that had not metastasized (p = 0.007). Subsequent mutation analysis revealed a higher mutation rate for PTPRD than has been reported in any other cancer type, with 37% of tumors harboring a somatic mutation. Conversely, bisulfite sequencing showed that methylation was not a mechanism of PTPRD disruption in cSCC. This is the first report to observe an association between deletion within PTPRD and metastatic disease and highlights the potential use of these deletions as a diagnostic biomarker for tumor progression. Combined with the high mutation rate observed in our study, PTPRD is one of the most commonly altered genes in cSCC and warrants further investigation to determine its significance for metastasis in other tumor types

The Genomic Landscape of Actinic Keratosis

Actinic keratoses (AKs) are lesions of epidermal keratinocyte dysplasia and are precursors for invasive cutaneous squamous cell carcinoma (cSCC). Identifying the specific genomic alterations driving the progression from normal skin to skin with AK to skin with invasive cSCC is challenging because of the massive UVR-induced mutational burden characteristic at all stages of this progression. In this study, we report the largest AK whole-exome sequencing study to date and perform a mutational signature and candidate driver gene analysis on these lesions. We demonstrate in 37 AKs from both immunosuppressed and immunocompetent patients that there are significant similarities between AKs and cSCC in terms of mutational burden, copy number alterations, mutational signatures, and patterns of driver gene mutations. We identify 44 significantly mutated AK driver genes and confirm that these genes are similarly altered in cSCC. We identify azathioprine mutational signature in all AKs from patients exposed to the drug, providing further evidence for its role in keratinocyte carcinogenesis. cSCCs differ from AKs in having higher levels of intrasample heterogeneity. Alterations in signaling pathways also differ, with immune-related signaling and TGFβ signaling significantly more mutated in cSCC. Integrating our findings with independent gene expression datasets confirms that dysregulated TGFβ signaling may represent an important event in AK‒cSCC progression

Topical immunomodulation under systemic immunosuppression: results of a multicentre, randomized, placebo-controlled safety and efficacy study of imiquimod 5% cream for the treatment of actinic keratoses in kidney, heart, and liver transplant patients.

OBJECTIVE: In this study the safety and efficacy of imiquimod 5% cream for the treatments of actinic keratoses in kidney, heart and liver transplant recipients is evaluated. BACKGROUND: Growing populations of organ transplant recipients face increased risk of developing actinic keratosis (AK) and skin cancer secondary to continuous systemic immunosuppressive therapy. Imiquimod 5% cream is an effective option for the treatment of AK, but the safety of topical immune stimulation in immunocompromised patients has not been widely evaluated. METHODS: A total of 43 patients in six European transplant centres applied two sachets of topical imiquimod or vehicle cream three times per week to a 100 cm(2) field. Dosing continued for 16 weeks regardless of lesion clearance. Patients were assessed for safety variables that included adverse events, local skin reactions, laboratory results, vital signs, dosage of immunosuppressive medication and indication of graft rejection. A blinded independent expert committee was responsible for safety monitoring and final safety assessment. RESULTS: No graft rejections or trends for a deterioration of graft function were detected. No meaningful trends were observed in laboratory results. Among patients randomized to imiquimod, the complete clearance rate was 62.1% (18/29); for vehicle patients, the complete clearance rate was 0% (0/14). Clinical clearance was confirmed histologically in all cases. CONCLUSIONS: Imiquimod appears to be a safe alternative for the treatment of multiple actinic keratoses in patients with solid organ transplants. Efficacy was within the range previously observed in nontransplanted populations

Topical immunomodulation under systemic immunosuppression: results of a multicentre, randomized, placebo-controlled safety and efficacy study of imiquimod 5% cream for the treatment of actinic keratoses in kidney, heart, and liver transplant patients.

OBJECTIVE: In this study the safety and efficacy of imiquimod 5% cream for the treatments of actinic keratoses in kidney, heart and liver transplant recipients is evaluated. BACKGROUND: Growing populations of organ transplant recipients face increased risk of developing actinic keratosis (AK) and skin cancer secondary to continuous systemic immunosuppressive therapy. Imiquimod 5% cream is an effective option for the treatment of AK, but the safety of topical immune stimulation in immunocompromised patients has not been widely evaluated. METHODS: A total of 43 patients in six European transplant centres applied two sachets of topical imiquimod or vehicle cream three times per week to a 100 cm(2) field. Dosing continued for 16 weeks regardless of lesion clearance. Patients were assessed for safety variables that included adverse events, local skin reactions, laboratory results, vital signs, dosage of immunosuppressive medication and indication of graft rejection. A blinded independent expert committee was responsible for safety monitoring and final safety assessment. RESULTS: No graft rejections or trends for a deterioration of graft function were detected. No meaningful trends were observed in laboratory results. Among patients randomized to imiquimod, the complete clearance rate was 62.1% (18/29); for vehicle patients, the complete clearance rate was 0% (0/14). Clinical clearance was confirmed histologically in all cases. CONCLUSIONS: Imiquimod appears to be a safe alternative for the treatment of multiple actinic keratoses in patients with solid organ transplants. Efficacy was within the range previously observed in nontransplanted populations

Primary cutaneous posttransplant lymphoproliferative disorders in solid organ transplant recipients: a multicenter European case series.

Primary cutaneous posttransplant lymphoproliferative disorders (PTLD) are rare. This retrospective, multicenter study of 35 cases aimed to better describe this entity. Cases were (re)-classified according to the WHO-EORTC or the WHO 2008 classifications of lymphomas. Median interval between first transplantation and diagnosis was 85 months. Fifty-seven percent of patients had a kidney transplant. Twenty-four cases (68.6%) were classified as primary cutaneous T cell lymphoma (CTCL) and 11 (31.4%) as primary cutaneous B cell PTLD. Mycosis fungoides (MF) was the most common (50%) CTCL subtype. Ten (90.9%) cutaneous B cell PTLD cases were classified as EBV-associated B cell lymphoproliferations (including one plasmablastic lymphoma and one lymphomatoid granulomatosis) and one as diffuse large B cell lymphoma, other, that was EBV-negative. Sixteen (45.7%) patients died after a median follow-up of 19.5 months (11 [68.8%] with CTCL [6 of whom had CD30(+) lymphoproliferative disorders (LPD)] and 5 [31.2%] with cutaneous B cell PTLD. Median survival times for all patients, CTCL and cutaneous B cell PTLD subgroups were 93, 93, and 112 months, respectively. Survival rates for MF were higher than those for CD30(+) LPD. The spectrum of primary CTCL in organ transplant recipients (OTR) is similar to that in the general population. The prognosis of posttransplant primary cutaneous CD30(+) LPD is worse than posttransplant MF and than its counterpart in the immunocompetent population. EBV-associated cutaneous B cell LPD predominates in OTR