C Proby

Increased risk of skin cancer associated with the presence of epidermodysplasia verruciformis human papillomavirus types in normal skin.

Background  Human papillomaviruses (HPVs) are found in normal skin and in benign and malignant skin conditions. Epidermodysplasia verruciformis (EV) HPV types are those most plausibly linked to the development of squamous cell carcinomas of the skin.

Treatment of post-transplant premalignant skin disease: a randomized intrapatient comparative study of 5-fluorouracil cream and topical photodynamic therapy.

Background  Organ transplant recipients (OTR) are at high risk of developing nonmelanoma skin cancer and premalignant epidermal dysplasia (carcinoma in situ/ Bowens disease and actinic keratoses). Epidermal dysplasia is often widespread and there are few comparative studies of available treatments.

Overexpression of the Axl tyrosine kinase receptor in cutaneous SCC-derived cell lines and tumours

The molecular mechanisms that underlie the development of squamous cell skin cancers (SSC) are poorly understood. We have used oligonucleotide microarrays to compare the differences in cellular gene expression between a series of keratinocyte cell that mimic disease progression with the aim of identifying genes that may potentially contribute towards squamous cell carcinoma (SCC) progression in vivo, and in particular to identify markers that may serve as potential therapeutic targets for SCC treatment. Gene expression differences were corroborated by polymerase chain reaction and Western blotting. We identified Axl, a receptor tyrosine kinase with transforming potential that has also been shown to have a role in cell survival, adhesion and chemotaxis, was upregulated in vitro in SCC-derived cells compared to premalignant cells. Extending the investigation to tumour biopsies showed that the Axl protein was overexpressed in vivo in a series of SCCs.

PTCH mutations in basal cell carcinomas from azathioprine-treated organ transplant recipients.

The immunosuppressant azathioprine is used to prevent graft rejection after organ transplantation. To investigate whether azathioprine-associated mutagenesis contributes to the high incidence of skin tumours in organ transplant recipients (OTRs), we analysed PTCH gene mutations in 60 basal cell carcinomas (BCC); 39 from OTRs receiving azathioprine and 21 from individuals never exposed to azathioprine. PTCH was mutated in 55% of all tumours, independent of azathioprine treatment. In both the azathioprine and non-azathioprine groups, transitions at dipyrimidine sequences, considered to indicate mutation by ultraviolet-B radiation, occurred frequently in tumours from chronically sun-exposed skin. In BCC from non-sun-exposed skin of azathioprine-treated patients, there was an over-representation of unusual G:C to A:T transitions at non-dipyrimidine sites. These were exclusive to the azathioprine-exposed group and all in the same TGTC sequence context at different positions within PTCH. Meta-analysis of 247 BCCs from published studies indicated that these mutations are rare in sporadic BCC and had never previously been reported in this specific sequence context. This study of post-transplant BCC provides the first indication that azathioprine exposure may be associated with PTCH mutations, particularly in tumours from non-sun-exposed skin.

Detection and typing of human papillomaviruses in mucosal and cutaneous biopsies from immunosuppressed and immunocompetent patients and patients with epidermodysplasia verruciformis: a unified diagnostic approach.

AIM: To develop a unified diagnostic approach for the detection of human papillomavirus (HPV) DNA in skin and mucosal biopsies from both immunocompetent and immunosuppressed individuals using a degenerate polymerase chain reaction (PCR) method. METHODS: The sensitivity and specificity of three published degenerate primer sets (HVP2/B5 and F14/B15; MY09/MY11; CP62/69 outer and CP65/68 nested primer pairs) were evaluated in PCR reactions with serial dilutions of 12 representative cloned HPV types. This combination of primers was then used to detect HPV DNA in 49 benign and malignant lesions of cutaneous and mucosal origin from immunosuppressed, immunocompetent, and epidermodysplasia verruciformis (EV) patients, and compared with detection rates using single primer sets alone. RESULTS: The observed sensitivity of MY09/MY11 and CP62/69 + CP65/68 was high for mucosal and EV HPV types, respectively. The sensitivity of all primer sets for cutaneous types was low, but nonetheless the use of this combination of primers allowed HPV DNA detection in all of the benign warts analysed. Several mixed infections were also identified. A high prevalence of HPV DNA was similarly detected in squamous cell carcinomas from immunocompromised patients; the HPV types found were exclusively EV related. CONCLUSIONS: The use of a combined degenerate primer PCR approach considerably improves HPV DNA detection over individual primer sets and allows detection of mixed infections. The findings may help explain the discrepancies in published reports relating to HPV DNA detection in benign and malignant skin lesions. Further modifications to this method are in progress which should significantly improve comprehensive HPV detection and typing for diagnostic purposes.

Does human papillomavirus play a role in the development of bladder transitional cell carcinoma? A comparison of PCR and immunohistochemical analysis

Aim: To investigate the role of human papillomavirus (HPV) in the development of bladder transitional cell carcinoma (TCC). Methods: Seventy eight paraffin wax embedded TCC samples were tested for the presence of HPV by two methods. First, immunohistochemistry was carried out using a polyclonal antibody capable of detecting the capsid protein of all known papillomaviruses. The second method was a consensus GP5+/6+ primer mediated polymerase chain reaction (PCR) technique, with the products analysed by both agarose gel electrophoresis and an enzyme immunoassay using type specific oligonucleotide probes for 10 different mucosal genotypes. To exclude false negative results because of the poor quality of DNA extracted from paraffin wax embedded samples, the series was extended to include 20 further blocks for which the corresponding snap frozen unfixed tissue was available. Results: The two methods produced contrasting results, with 47 of the 78 samples positive for HPV antigen and none positive for HPV DNA. HPV DNA was not detected in the 20 additional paraffin wax embedded TCCs or in the 20 paired unfixed samples. In contrast, HPV DNA was amplified by PCR from all six of the paraffin wax embedded cervical carcinoma and anogenital wart control samples. Conclusion: The disparity between the two sets of results is probably caused by false positives resulting from the non-specificity of the polyclonal antibody used for immunohistochemistry. These results suggest that HPV is unlikely to play an aetiological role in the development of bladder TCC.

Single Nucleotide Polymorphism Array Analysis Defines a Specific Genetic Fingerprint for Well-Differentiated Cutaneous SCCs

Cutaneous squamous cell carcinomas (cSCCs) are the second most frequent cancers in fair-skinned populations; yet, because of their genetic heterogeneity, the key molecular events in cSCC tumorigenesis remain poorly defined. We have used single nucleotide polymorphism microarray analysis to examine genome-wide allelic imbalance in 60 cSCCs using paired non-tumor samples. The most frequent recurrent aberrations were loss of heterozygosity at 3p and 9p, observed in 39 (65%) and 45 (75%) tumors, respectively. Microdeletions at 9p23 within the protein tyrosine phosphatase receptor type D (PTPRD) locus were identified in 9 (15%) samples, supporting a tumor suppressor role for PTPRD in cSCC. In addition, microdeletions at 3p14.2 were detected in 3 (5%) cSCCs, implicating the fragile histidine triad (FHIT) gene as a possible target for inactivation. Statistical analysis revealed that well-differentiated cSCCs demonstrated significantly fewer aberrations than moderately and poorly differentiated cSCCs; yet, despite a lower rate of allelic imbalance, some specific aberrations were observed equally frequently in both groups. No correlation was established between the frequency of chromosomal aberrations and immune or human papillomavirus status. Our data suggest that well-differentiated tumors are a genetically distinct subpopulation of cSCC.

A novel human papillomavirus identified in epidermodysplasia verruciformis

Epidermodysplasia verruciformis (EV) is a rare inherited condition in which there is widespread infection with human papillomavirus (HPV). Patients have a high risk of developing squamous cell carcinoma and Bowens disease on sun‐exposed sites. We describe a Jatnaican man with the typical clinical and histopathological features of EV. HPV 8·24 and a subtype of HPV 38, along with a novel HPV sequence most closely related to HPV 9 have been detected in his skin lesions. Although skin tumours are rare In black patients with EV and he has lived in a temperate climate most of his life, several of the lesions showed bowenoid atypia and he is at risk of developing invasive cutaneous malignancies.

Genital and cutaneous human papillomavirus (HPV) types in relation to conjunctival squamous cell neoplasia: A case-control study in Uganda

BackgroundWe investigated the role of infection with genital and cutaneous human papillomavirus types (HPV) in the aetiology of ocular surface squamous neoplasia (which includes both conjunctival intraepithelial neoplasia (CIN) and carcinoma) using data and biological material collected as part of a case-control study in Uganda.ResultsAmong 81 cases, the prevalence of genital and cutaneous HPV types in tumour tissue did not differ significantly by histological grade of the lesion. The prevalence of genital HPV types did not differ significantly between cases and controls (both 38%; Odds ratio [OR] 1.0, 95% confidence interval [CI] 0.4–2.7, p = 1.0). The prevalence of cutaneous HPV types was 22% (18/81) among cases and 3% (1/29) among controls (OR 8.0, 95% CI 1.0–169, p = 0.04).ConclusionWe find no evidence of an association between genital HPV types and ocular surface squamous neoplasia. The prevalence of cutaneous HPV was significantly higher among cases as compared to controls. Although consistent with results from two other case-control studies, the relatively low prevalence of cutaneous HPV types among cases (which does not differ by histological grade of tumour) indicates that there remains considerable uncertainty about a role for cutaneous HPV in the aetiology of this tumour.

Melanomas in renal transplant recipients: the London experience, and invitation to participate in a European study.

Sir, In response to the report of Le Mire et al.1 on the incidence of malignant melanoma in Oxford renal transplant recipients (RTRs), we detail our experience of melanoma in a series of RTRs at Bart’s and the London NHS Trust. Although incidence rates in our population were similar to those documented in the Oxford study, metastatic disease was more common, and we suspect that RTRs with melanoma may have a worse prognosis than their immunocompetent counterparts, although larger, multicentre studies are now required to confirm this. A retrospective clinical and histological review of melanomas diagnosed in patients attending a dedicated RTR dermatology clinic between 1990 and 2005 was performed. All specimens were resectioned and were assessed by an experienced dermatopathologist (R.C.). In a total population of 861 RTRs with a follow-up period of 8557 patient-years, there were seven cases of de novo melanoma (five invasive and two in situ) in three men and four women. All diagnoses were made in the RTR dermatology clinic. Clinicopathological data are presented in Table 1 and are illustrated in Figure 1. All patients were on prednisolone and azathioprine, with or without ciclosporin. The mean age at diagnosis was older than in Oxford [57·7 years (range 44-68) vs. 41] and the mean time from transplantation was shorter [102 months (range 10-247) vs. 132]. All patients had skin types I-III (although 20% of our RTR cohort have skin type V or VI). None had a family history of melanoma or fulfilled criteria for atypical mole syndrome, although two patients had several atypical naevi. A high proportion of patients had a history of other invasive skin tumours (five of seven vs. four of 10 in Oxford); in all but one patient (patient 1) these tumours arose prior to the diagnosis of melanoma. Melanomas were more commonly located on the head and neck in our series, with four of seven tumours occurring at this site, in contrast to the Oxford tumours which all occurred at extracephalic sites. Ten of 12 tumours in the Oxford series were superficial spreading melanomas, whereas this subtype accounted for two of our seven cases. As in the Oxford series, Breslow thickness in the majority of cases (five of seven) was < 1 mm, and an inflammatory response was either minimal or absent in all melanomas, as has previously been documented.2 A contiguous pre-existing naevus was present in only one case, and, similarly, was detected in only a minority (three of 12) of the Oxford cases, in contrast to a previous proposal that over half of all transplant melanomas arise in pre-existing naevi.2 All melanomas in our series were treated by complete surgical excision; sentinel lymph node biopsy was not available at the time these tumours were diagnosed. In most cases immunosuppression was reduced, but not stopped. Fig 1 Clinical and histological examples of melanoma in renal transplant recipients. (a) Patient 6: lentigo maligna melanoma on right side of nose, Breslow thickness 0·4 mm. (b) Patient 2: lentigo maligna on cheek. (c) Photomicrograph of histology, ... Table 1 Clinicopathological data This series represents an elevated incidence of melanoma in our London RTR cohort: the rate in 2003 for the general population in North East Thames was 6·5 and 8·1 per 100 000 population for men and women, respectively, and we would therefore have expected approximately 0·9 cases of melanoma to have arisen in our cohort (in which 64% are male). If in situ tumours are included, these 7 cases represent an approximately 7·8-fold increased incidence compared with the general population. This is remarkably similar to the eightfold increased rate found in Oxford, and is of the same order as that reported by Moloney et al.3 who reported a 6·6-fold increase in males with melanoma in an Irish transplant population. These more recent studies report rates higher than previous estimates.4-6 Three patients in our series, but only one patient in Oxford, died from metastatic melanoma. Two deaths occurred in RTRs with melanomas exceeding 2 mm Breslow thickness. In accordance with American Joint Committee on Cancer staging, the predicted 5-year survival for patient 3 was 67% and that for patient 4 was 63%,7 yet both died within approximately 2 years. Even more unexpectedly, patient 6 developed metastases from a lentigo maligna melanoma of Breslow thickness 0·4 mm, for which the expected 5-year survival is 95% or greater. Our series of patients is too small to give statistical confirmation of a poorer prognosis in RTRs and previous studies have also not had sufficient power to examine this, although a compromised outcome from melanoma has similarly been observed in individuals with human immunodeficiency virus infection or AIDS.8 The incidence of melanoma is rising faster than for any other major cancer and will continue to do so over at least the next 30 years.9 In conjunction with the steadily improving long-term survival from organ transplantation, it is likely that post-transplant melanoma will emerge as an increasing clinical problem in coming years. Many important questions have yet to be answered in this respect: whether prognosis is, indeed, worse for post-transplant melanoma, whether more aggressive management strategies are therefore required, and how reduction in immunosuppression should be approached. Although consensus statements such as those recently reported in this Journal are a useful guideline to management of post-transplant skin cancer,10 a firmer evidence base is now required. This is a particular priority for management of post-transplant melanoma, and sufficient power to reach meaningful conclusions is only likely to be achieved in the context of a multicentre study. Such a study is currently being coordinated within the SCOPE network (Skin Care in Organ transplant Patients, Europe: http://www.scopnetwork.org) by our centre, and we invite clinicians who are interested in participating to contact us.