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Biomedical subjects

C A Harwood

Publications and source records attributed to C A Harwood.

At least 19 recordsLinked to original sources
PubMed2007

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/ Bowen's disease and actinic keratoses). Epidermal dysplasia is often widespread and there are few comparative studies of available treatments. OBJECTIVES: To compare topical methylaminolaevulinate (MAL) photodynamic therapy (PDT) with topical 5% fluorouracil (5-FU) cream in the treatment of post-transplant epidermal dysplasia. METHODS: Eight OTRs with epidermal dysplasia were recruited to an open-label, single-centre, randomized, intrapatient comparative study. Treatment with two cycles of topical MAL PDT 1 week apart was randomly assigned to one area of epidermal dysplasia, and 5-FU cream was applied twice daily for 3 weeks to a clinically and histologically comparable area. Patients were reviewed at 1, 3 and 6 months after treatment. The main outcome measures were complete resolution rate (CRR), overall reduction in lesional area, treatment-associated pain and erythema, cosmetic outcome and global patient preference. RESULTS: At all time points evaluated after completion of treatment, PDT was more effective than 5-FU in achieving complete resolution: eight of nine lesional areas cleared with PDT (CRR 89%, 95% CI: 0.52-0.99), compared with one of nine lesional areas treated with 5-FU (CRR 11%, 95% CI: 0.003-0.48) (P = 0.02). The mean lesional area reduction was also proportionately greater with PDT than with 5-FU (100% vs. 79% respectively). Cosmetic outcome and patient preference were also superior in the PDT-treated group. CONCLUSIONS: Compared with topical 5-FU, MAL PDT was a more effective and cosmetically acceptable treatment for epidermal dysplasia in OTRs and was preferred by patients. Further studies are now required to confirm these results and to examine the effect of treating epidermal dysplasia with PDT on subsequent development of squamous cell carcinoma in this high risk population.

Administration, Topical↗
PubMed2006

Specialist dermatology clinics for organ transplant recipients significantly improve compliance with photoprotection and levels of skin cancer awareness.

BACKGROUND: Organ transplant recipients (OTRs) have 100-fold increased risk of developing squamous cell carcinomas. Cumulative exposure to ultraviolet radiation is the main risk factor and there is evidence that lack of dermatological surveillance may be responsible for poor levels of knowledge and photoprotection among OTRs. OBJECTIVES: This study evaluated whether routine consultation in a specialist OTR dermatology clinic improves understanding of skin cancer risk and compliance with photoprotection measures. METHODS: A cross-sectional questionnaire-based study was performed in a specialist OTR dermatology clinic at Bart's and the London NHS Trust, London, U.K. The subjects were 399 white-skinned patients under surveillance in a renal transplant clinic, who were sent a postal questionnaire from the renal transplant clinic. The main outcome measures were responses to the questionnaire regarding photoprotective practices and skin cancer risk awareness. RESULTS: Two hundred and ninety-two of 399 (73%) responded, of whom 89% had previously attended the specialist dermatology clinic. Ninety-six per cent recalled receiving photoprotection advice at least once (85% from dermatologists); 92% reported use of sunscreen; 88% specifically dressed to photoprotect themselves; 96% directly avoided sun exposure during summer; 68% were aware that an increased risk of skin cancer was the reason that extra photoprotective measures were important after a transplant. Photoprotective measures and level of skin cancer awareness were significantly lower in those responders who had never attended the specialist clinic. No obvious bias was identified among nonresponders. CONCLUSIONS: Skin cancer awareness and compliance with photoprotective measures in our patient population is generally greater than previously reported, suggesting that delivery of educational messages regarding skin cancer may be improved if provided in a specialist dermatological setting.

Cross-Sectional Studies↗
PubMed2005

Imiquimod cream 5% for recalcitrant cutaneous warts in immunosuppressed individuals.

BACKGROUND: Viral warts may cause significant morbidity in individuals unable to mount an adequate T-helper 1 cell-mediated immune response to human papillomavirus. Imiquimod is a potent inducer of antiviral cytokine activity which has shown significant efficacy in the treatment of genital warts. Similar efficacy in cutaneous warts is not yet established. OBJECTIVES: To assess the response of persistent cutaneous warts to 5% imiquimod cream in immunosuppressed individuals. METHODS: Fifteen immunosuppressed patients with warts on the hands and/or feet present for more than 18 months, which had failed to respond to a minimum of 12 weeks of topical salicylic acid and four cycles of cryotherapy, were recruited. Imiquimod 5% cream was applied in an open label, right vs. left comparison study for 24 weeks (three times weekly for 8 weeks, daily for 8 weeks, then daily with occlusion for 8 weeks). RESULTS: Twelve (80%) patients completed the study protocol. Benefit was seen in five patients [36% in the intent-to-treat analysis (14 patients)], including more than 30% clearance of warts in three patients and reduction in overall size of warts in two further cases. Local skin reactions occurred in four (29%) patients and were usually mild. A transient rise in creatinine (11-29% above baseline) was measured in three renal transplant recipients, but we did not consider that this was related to imiquimod exposure. CONCLUSIONS: This is the first controlled study to assess therapeutic efficacy of topical 5% imiquimod cream in persistent warts associated with immunosuppression. It provides preliminary evidence that topical imiquimod may benefit a subgroup of immunosuppressed patients with recalcitrant cutaneous warts.

Administration, Cutaneous↗
PubMed2005

Primary cutaneous B-cell lymphoma associated with actinic prurigo.

We describe two patients with a diagnosis of actinic prurigo who subsequently developed cutaneous B-cell lymphoma. This is the first report, to our knowledge, of this association. We propose that chronic antigenic stimulation by ultraviolet radiation, in the context of actinic prurigo, may have been causal in the development of these unusual lymphomas.

Child↗
PubMed2004

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. OBJECTIVES: To assess the risk of nonmelanoma skin cancer (NMSC) associated with the presence of EV HPV in normal skin in immunocompetent (IC) individuals and renal transplant recipients (RTRs). METHODS: Using a degenerate and nested polymerase chain reaction technique, HPV DNA was sought in 124 normal skin samples from sun-exposed and nonsun-exposed sites, from 39 IC individuals and 38 RTRs, both with and without NMSC. Data were analysed using the Mantel-Haenszel test and by logistic regression analysis. RESULTS: HPV DNA was detected in 58/67 (87%) and 20/57 (35%) samples from renal transplant and IC patients, respectively. There was no difference in either the prevalence or spectrum of HPV types found in sun-exposed and nonsun-exposed normal skin. However, there was significant association between NMSC and the presence of EV HPV DNA. Multivariate analysis provided an odds ratio of 6.41 (95% confidence interval 1.79-22.9) for the association of EV HPV DNA in normal skin (irrespective of site) and NMSC status, even after stratifying for patient group and adjusting for the clustering effect of multiple sampling. Conversely, there was no association between skin cancer status and the presence of cutaneous or mucosal HPV types in either sun-exposed or nonsun-exposed skin. CONCLUSIONS: HPV DNA is widespread in normal adult skin, particularly in transplant patients. In our study, the presence of EV but not cutaneous HPV DNA in normal skin was significantly associated with NMSC status and may prove to be of predictive value for skin cancer risk. These data provide reason to focus on EV HPV types as causal agents in skin cancer.

Adult↗
PubMed2001

An association between sebaceous carcinoma and microsatellite instability in immunosuppressed organ transplant recipients.

Sebaceous carcinomas are rare cutaneous appendageal tumors that may occur sporadically or in association with an internal malignancy in Muir-Torre syndrome. In Muir-Torre syndrome microsatellite instability can often be demonstrated in tumor DNA as a result of an inherited mutation in one of several known mismatch repair genes; however, the role of microsatellite instability in sporadic sebaceous carcinomas has not been previously studied. In this report we describe the clinicopathologic characteristics of a series of unselected sebaceous carcinomas and examine them for the presence of microsatellite instability. Of 10 consecutive tumors identified over a 10 y period, only one was from a patient known to have Muir-Torre syndrome. Of the nine presumed sporadic cases, five were from four renal transplant recipients and four from otherwise healthy individuals. Microsatellite instability was demonstrable in three cases: in the Muir-Torre syndrome-associated tumor and in two tumors from transplant patients. Microsatellite instability was subsequently also found in a sebaceous carcinoma from a further transplant patient prospectively sought from another institution. The presence of microsatellite instability in post-transplant sebaceous carcinomas was associated with loss of expression of the mismatch repair protein hMSH2. In summary, sebaceous gland carcinomas, while characteristic of Muir-Torre syndrome, are commonly found outside this context. Among presumed sporadic cases, our data suggest they may be over-represented in immunosuppressed renal transplant recipients. The presence of microsatellite instability in transplant-associated lesions, together with loss of hMSH2 expression suggests that immunosuppression might unmask a previously silent Muir-Torre syndrome phenotype in some cases. Alternatively, there is experimental evidence to suggest that immunosuppressive drugs, most plausibly azathioprine, could select for the emergence of a mutator phenotype and thus predispose to the development of sebaceous carcinomas. The role of mismatch repair defects in other post-transplant skin malignancies remains to be established.

Aged↗
PubMed2000

Human papillomavirus infection and non-melanoma skin cancer in immunosuppressed and immunocompetent individuals.

The role of human papillomavirus (HPV) in anogenital carcinogenesis is established firmly, but a similar role in non-melanoma skin cancer remains speculative. Certain immunosuppressed individuals have an increased incidence of both viral warts and non-melanoma skin cancer, that has prompted the suggestion that HPV may play a pathogenic role. Differences in the techniques used to detect HPV DNA in skin, however, have led to discrepancies in the prevalence and spectrum of HPV types reported in these malignancies. This study describes the use of a comprehensive degenerate PCR technique to compare the HPV status of 148 Non-melanoma skin cancers from immunosuppressed and immunocompetent individuals. HPV DNA was detected in 37/44 (84.1%) squamous cell carcinomas, 18/24 (75%) basal cell carcinomas and 15/17 (88.2%) premalignant skin lesions from the immunosuppressed group compared with 6/22 (27.2%) squamous cell carcinomas, 11/30 (36.7%) basal cell carcinomas and 6/11 (54. 4%) premalignancies in the immunocompetent group. Epidermodysplasia verruciformis HPV types prevailed in all lesion types from both groups of patients. In immunosuppressed individuals, cutaneous HPV types were also identified at high frequency, and co-detection of multiple HPV types within single tumours was commonly observed. This study represents the largest and most comprehensive analysis of the HPV status of non-melanoma skin cancers yet undertaken; whereas there are clearly significant differences in non-melanoma skin cancers from immunosuppressed and immunocompetent populations, we provide evidence that the prevalence and spectrum of HPV types does not differ in squamous cell carcinomas, basal cell carcinomas or premalignancies within the two populations. These data have important implications for future investigation of the role of HPV in cutaneous carcinogenesis at a functional level.

Adult↗
PubMed2000

A common polymorphism acts as an intragenic modifier of mutant p53 behaviour.

The p73 protein, a homologue of the tumour-suppressor protein p53, can activate p53-responsive promoters and induce apoptosis in p53-deficient cells. Here we report that some tumour-derived p53 mutants can bind to and inactivate p73. The binding of such mutants is influenced by whether TP53 (encoding p53) codon 72, by virtue of a common polymorphism in the human population, encodes Arg or Pro. The ability of mutant p53 to bind p73, neutralize p73-induced apoptosis and transform cells in cooperation with EJ-Ras was enhanced when codon 72 encoded Arg. We found that the Arg-containing allele was preferentially mutated and retained in squamous cell tumours arising in Arg/Pro germline heterozygotes. Thus, inactivation of p53 family members may contribute to the biological properties of a subset of p53 mutants, and a polymorphic residue within p53 affects mutant behaviour.

Alleles↗
PubMed1999

Role of human papillomaviruses in cutaneous and oral manifestations of immunosuppression.

Long-term immunosuppressive drug regimes, used to prevent organ transplant rejection, are associated with an increased risk of epithelial malignancies particularly anogenital and cutaneous cancers. Premalignant and malignant lesions of the oral mucosa have also been reported in renal transplant recipients (RTRs), particularly of sun-exposed lip lesions. Many of these anogenital lesions are associated with the detection of high-risk mucosal human papillomaviruses (HPV). Novel degenerate and nested polymerase chain reaction (PCR) techniques have found high levels of epidermodysplasia verruciformis (EV) HPVs (high-risk cutaneous oncogenic HPVs) in cutaneous warts, dysplastic keratoses, and squamous cell carcinomas. Unusual appendageal and spindle cell carcinomas are being observed in RTRs. Increasing survival times of HIV-positive patients may be associated with dysplasia of orogenital mucosal epithelium, and careful epidemiologic studies of cutaneous lesions are needed. The role of HPVs in the development of these lesions has yet to be established.

Adult↗
PubMed1999

Degenerate and nested PCR: a highly sensitive and specific method for detection of human papillomavirus infection in cutaneous warts.

The role of human papillomavirus (HPV) in anogenital carcinogenesis is firmly established, but evidence that supports a similar role in skin remains speculative. Immunosuppressed renal transplant recipients have an increased incidence of viral warts and nonmelanoma skin cancer, and the presence of HPV DNA in these lesions, especially types associated with the condition epidermodysplasia verruciformis (EV), has led to suggestions that HPV may play a pathogenic role. However, differences in the specificities and sensitivities of techniques used to detect HPV in skin have led to wide discrepancies in the spectrum of HPV types reported. We describe a degenerate nested PCR technique with the capacity to detect a broad spectrum of cutaneous, mucosal, and EV HPV types. In a series of 51 warts from 23 renal transplant recipients, this method detected HPV DNA in all lesions, representing a significant improvement over many previously published studies. Cutaneous types were found in 84.3% of warts and EV types were found in 80.4% of warts, whereas mucosal types were detected in 27.4% of warts. In addition, the method allowed codetection of two or more distinct HPV types in 94.1% of lesions. In contrast, single HPV types were detected in all but 1 of 20 warts from 15 immunocompetent individuals. In summary, we have established a highly sensitive and comprehensive degenerate PCR methodology for detection and genotyping of HPV from the skin and have demonstrated a diverse spectrum of multiple HPV types in cutaneous warts from transplant recipients. Studies designed to assess the significance of these findings to cutaneous carcinogenesis are under way.

Base Sequence↗
PubMed1999

Human papillomavirus and the development of non-melanoma skin cancer.

Human papillomaviruses (HPV) are increasingly recognised as important human carcinogens. The best established association with human malignancy is that of high-risk mucosal HPV types and anogenital cancer. HPV-induced transformation of anogenital epithelia has been the subject of intense research which has identified the cellular tumour suppressor gene products, p53 and pRB, as important targets for the viral oncoproteins E6 and E7 respectively. Certain HPV types are also strongly associated with the development of non-melanoma skin cancer in the inherited disorder epidermodysplasia verruciformis (EV). However, in contrast with anogenital malignancy the oncogenic mechanisms of EV-HPV types remain uncertain, and there appears to be a crucial additional requirement for ultraviolet radiation. Cutaneous HPV types in the general population are predominantly associated with benign viral warts, but a role in non-melanoma skin cancer has recently been postulated. Polymerase chain reaction based HPV detection techniques have shown a high prevalence of HPV DNA, particularly in skin cancers from immunosuppressed patients and to a lesser extent in malignancies from otherwise immunocompetent individuals. No particular HPV type has yet emerged as predominant, and the role of HPV in cutaneous malignancy is unclear at present. It remains to be established whether HPV plays an active or purely a passenger role in the evolution of non-melanoma skin cancer.

Carcinoma, Squamous Cell↗
PubMed1998

p53 codon 72 polymorphism and risk of cervical cancer in UK.

BACKGROUND: A polymorphism at codon 72 of the human tumour-suppressor gene, p53, results in translation to either arginine or proline. A recent report suggested that the risk of human-papillomavirus-associated cervical cancer in white women is higher for those homozygous for the arginine allele than for those who are heterozygous. We examined a similar number of cervical cancers and a larger control group for their p53 codon 72 polymorphism status to see if we could confirm this result. METHODS: Three different groups of UK white women were studied: 96 who had volunteered to take part in a trial of ovarian-cancer screening; 150 attending for routine antenatal care in the Oxford region; and 50 women with cervical cancer. DNA from peripheral blood samples and from archival tissue samples was examined by PCR with allele-specific primers. FINDINGS: The proportions of individuals homozygous for the arginine allele, homozygous for the proline allele, and heterozygous for the two alleles were 59%, 4%, and 36% among women screened for ovarian cancer; 65%, 8%, and 27% among the antenatal-care group; and 54%, 6%, and 40% in women with cervical cancer. Chi2 analysis showed no significant differences in these proportions. INTERPRETATION: In the population studied, individuals homozygous for the arginine variant of codon 72 of the p53 gene were not at increased risk of cervical cancer.

Amino Acid Sequence↗
PubMed1998

Detection of human papillomavirus DNA in PUVA-associated non-melanoma skin cancers.

Psoralen and UVA (PUVA) photochemotherapy is associated with a dose-dependent increased risk of nonmelanoma skin cancer in patients treated for psoriasis. Like ultraviolet B radiation, PUVA is both mutagenic and immunosuppressive and may thus act as a complete carcinogen; however, the reversed squamous to basal cell carcinoma ratio (SCC:BCC) in PUVA-treated patients, also seen in immunosuppressed renal transplant recipients, suggests a possible cofactor role for human papillomavirus (HPV) infection. In this study we examine a large series of benign and malignant cutaneous lesions for the presence of HPV DNA from patients treated with high dose (> or =500 J per cm2) ultraviolet A. A panel of degenerate primers based on the L1 (major capsid protein) open reading frame was employed, designed to detect mucosal, cutaneous, and epidermodysplasia verruciformis HPV types with high sensitivity and specificity. HPV DNA was detected in 15 of 20 (75%) non-melanoma skin cancer, seven of 17 (41.2%) dysplastic PUVA keratoses, four of five (80%) skin warts, and four of 12 (33%) PUVA-exposed normal skin samples. The majority of HPV positive lesions contained epidermodysplasia verruciformis-related HPV including HPV-5, -20, -21, -23, -24, and -38. Possible novel epidermodysplasia verruciformis types were identified in further lesions. Mixed infection with epidermodysplasia verruciformis, cutaneous, and/or mucosal types was present in six of 30 (20%) of all HPV positive lesions, including in normal skin, warts, dysplastic PUVA keratoses, and squamous cell carcinomas. The prevalence and type of HPV infection in cutaneous lesions from PUVA-treated patients is similar to that previously reported in renal transplant-associated skin lesions, and suggests that the role of HPV in PUVA-associated carcinogenesis merits further study.

Adult↗