J M McGregor

Barts Health NHS Trust, Londinium, England, United Kingdom

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Publications (113)526.42 Total impact

  • J M McGregor · P Sasieni
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    ABSTRACT: The aim of our editorial was to examine the MSLT-1 data with an open mind and to bring some clarity to the sentinel node biopsy debate which still divides opinion. Informed doctors are needed to inform patient choice. Evidently you were not impressed with our attempts to do this. In fact, on reading your letter carefully, we think that we agree on much more than we disagree. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    No preview · Article · May 2015 · British Journal of Dermatology
  • A Gulati · C.A. Harwood · J Rolph · E Pottinger · J M Mcgregor · N Goad · C M Proby
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    ABSTRACT: Skin disorders account for over 20% of GP consultations. Half of dermatology referrals to secondary care are for skin lesions, but only 12% of urgent skin cancer referrals are deemed appropriate. Suitably designed online learning resources may positively impact GP confidence in the recognition of skin cancer and improve patient outcomes. This study evaluated the impact of a national, online, skin cancer recognition toolkit on GP confidence and knowledge in diagnosing skin cancers and referral behaviour to secondary care. The toolkit, consisting of a referral decision aid, lesion recognition resource, clinical cases and a quiz, was launched in March 2012. Website usage statistics and online focus groups were used to assess the usability of the website and perceived changes in behaviour. The impact of the toolkit was assessed using national skin cancer referral data, cross-sectional questionnaires and urgent skin cancer referral data to two NHS trusts. The toolkit was accessed by 20% of GPs in England from 20th March to 31st October 2012; spending a mean of over 5 minutes each, with over 33% return users. A survey revealed that the toolkit improved perceptions of skin cancer training and self-reported knowledge about skin cancer referral pathways. Analysis of referral patterns did not identify an impact of the toolkit on number or appropriateness of urgent skin cancer referrals in the eight months following the launch of the website. Online focus groups confirmed the usefulness of the resource and suggested a positive influence on knowledge and referral behaviour. The skin cancer toolkit is an accessible online learning resource for improving confidence with skin cancer referral amongst GPs. Although we were unable to identify any immediate changes in skin cancer diagnoses or appropriate referral behaviours, research is required to evaluate its longer term effects on outcomes. © 2015 European Academy of Dermatology and Venereology.
    No preview · Article · Apr 2015 · Journal of the European Academy of Dermatology and Venereology
  • J M McGregor · P Sasieni

    No preview · Article · Mar 2015 · British Journal of Dermatology

  • No preview · Article · Feb 2014
  • J M McGregor

    No preview · Article · Aug 2013 · British Journal of Dermatology
  • N. Clayton · A. Sadri · M. Boyce · V. Wolstenholme · C. Harwood · G. Moir · J. M. McGregor · R. Cerio

    No preview · Conference Paper · Jul 2013
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    R Atkar · M Ocampo · S Euvard · J McGregor · J Kanitakis · C Harwood
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    ABSTRACT: Ultraviolet radiation (UV) B is a substantial risk factor for skin cancer in both the immune competent and immunosuppressed organ transplant population (OTR). In OTRs, additional exposure to UVA through drug photosensitisation may contribute to their excess risk, which is well established. (1) There is some evidence for preferential lateralisation of photodamage and (pre)-cancers, in the general population, to the side most exposed to UVR whilst driving. Moehrle et al reported that left-sided drivers receive 5 times more UV to the left arm than the right arm, and 20 times more UV on the left side of the face than the right (2). Actinic keratoses have been reported to occur more frequently on the right side of the body in Australian drivers, where drivers sit on the right side of the car. A left sided bias in skin cancer was observed in the United States where drivers sit on the left side of the car (3, 4, 5). This article is protected by copyright. All rights reserved.
    Full-text · Article · Apr 2013 · British Journal of Dermatology
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    ABSTRACT: Skin cancer is a frequent complication of organ transplantation. Current guidelines advise specialist skin surveillance but there are limited data on how these should be implemented. This study determines overall burden of cancer and relevant intervals for strategic surveillance in an ethnically diverse transplant population. Prospective data on time to first and subsequent cancers and cumulative burden with respect to defined risk factors were analyzed in a cohort of 1010 patients in a UK center over 22 years. Among 931 individuals transplanted >6 months (mean 10.3 years), 1820 skin cancers occurred in 267 (29%) individuals and were multiple in 66%. Cumulative incidence at 5, 10, 20 and 30 years was 11%, 25%, 54% and 74%, with median time to second, third and fourth cancers of 24, 14.7 and 8.4 months, respectively. Tumors were overwhelmingly squamous and basal cell carcinomas (73% and 24%, respectively). Skin phototype, ultraviolet radiation exposure, age at transplant and duration of transplant were significant risk predictors and were used to construct clinically relevant surveillance intervals. This study provides a comprehensive, prospective analysis of skin cancer morbidity and risk in an ethnically diverse transplant population from which we derive an evidence-based skin cancer surveillance program.
    Full-text · Article · Oct 2012 · American Journal of Transplantation
  • R N Matin · P Szlosarek · J M McGregor · R Cerio · C A Harwood
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    ABSTRACT: An increased frequency of renal carcinoma in men with melanoma has been reported in population based-studies. We report the clinicopathological findings of five cases of synchronous renal cell carcinoma (RCC), identified after routine radiological staging for cutaneous malignant melanoma (MM) between October 2006 and October 2008. The five patients (three men and two women, with a mean age of 62.4 years), presented with six melanomas of varying subtypes. The mean Breslow thickness was 1.87 mm. There was no family history of cancer in any of the cases. Routine radiological staging identified a mass arising from the left kidney in three cases and the right kidney in two cases. All patients underwent radical nephrectomy, and histology in each case confirmed RCC of the clear-cell subtype. Mean follow-up was 3 years. Although the simultaneous occurrence of RCC and MM may be coincidental, there are several plausible aetiological links. Further analysis of the synchronous occurrence of MM and renal cancer may provide therapeutic insights into these two important tumours.
    No preview · Article · Jun 2012 · Clinical and Experimental Dermatology

  • No preview · Article · Feb 2012 · American Journal of Clinical Dermatology
  • Conal M. Perrett · Jane M. McGregor · Catherine A. Harwood
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    ABSTRACT: Thiopurines-azathioprine and 6-mercaptourine-inhibit purine biosynthesis and cause incorporation of 6-thioguanine nucleotides into DNA. Chronic thiopurine exposure increases the risk of skin cancer. This is well established in organ transplant recipients where azathioprine is a component of immunosuppressive regimens, but is currently less well recognized in patients on thiopurine monotherapy for IBD. Risk factors include age, duration of immunosuppression, and exposure to ultraviolet radiation in sunlight. Immunosuppressive therapy is thought to promote development of skin cancer by reducing immune surveillance. Thiopurines may also contribute directly to skin carcinogenesis as 6-thioguanine acts as a chromophore for solar ultraviolet A (UVA) radiation with resulting mutagenic DNA damage. The implications for IBD patients on thiopurines and strategies for managing this risk are discussed.
    No preview · Article · Jan 2012
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    ABSTRACT: Azathioprine is associated with enhanced skin photosensitivity to ultraviolet A (UVA) and leads to incorporation of 6-thioguanine (6-TG) into DNA of dividing cells. Unlike canonical DNA, 6-TG DNA is damaged by UVA, which comprises more than 90% of the ultraviolet reaching earth. Skin photosensitivity to UVA and UVB was measured in 48 kidney transplant patients immunosuppressed either by azathioprine (n = 32) or mycophenolate (n = 16). In 23 patients, azathioprine was subsequently replaced by mycophenolate and skin photosensitivity, DNA 6-TG content in peripheral blood mononuclear cells, and susceptibility to UVA-induced DNA damage were monitored for up to 2 years. The mean minimal erythema dose to UVA on azathioprine was twofold lower than on mycophenolate. Three months after replacing azathioprine by mycophenolate mofetil, the minimal erythema dose to UVA had increased from 15 to 25 J/cm(2) (p < 0.001) accompanied by reduced DNA 6-TG content. P53 protein expression in irradiated skin indicated reduced susceptibility to UVA-induced DNA damage. 6-TG DNA in peripheral blood mononuclear cells remained measurable for over 2 years. Replacing azathioprine selectively reduced the skin photosensitivity to UVA, attenuated UVA-induced skin DNA damage, and is likely based on incorporated 6-TG in DNA.
    Full-text · Article · Sep 2011 · American Journal of Transplantation
  • C.M. Perrett · C.A. Harwood · J.M. McGregor · J Warwick · R Cerio · P Karran
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    ABSTRACT: Organ transplant recipients (OTRs) have an increased risk of skin cancer. Treatment with azathioprine, commonly used in post-transplant immunosuppressive regimens, results in incorporation of 6-thioguanine (6-TG) into DNA. Mismatch repair (MMR)-defective cells are resistant to killing by 6-TG. Azathioprine exposure confers a survival advantage on MMR-defective cells, which are hypermutable and may therefore contribute to azathioprine-related nonmelanoma skin cancer, a phenomenon we have previously demonstrated in transplant-associated sebaceous carcinomas. The MSH2 protein is an important component of DNA MMR. The -6 exon 13 T>C MSH2 polymorphism is associated with impaired MMR, drug resistance and certain cancers. To investigate (i) whether loss of MMR protein expression and microsatellite instability are over-represented in squamous cell carcinomas (SCCs) from OTRs on azathioprine compared with SCCs from immunocompetent patients, and (ii) whether the MSH2 -6 exon 13 polymorphism is over-represented in OTRs with skin cancer on azathioprine. (i) Immunohistochemical staining was used to assess expression of the MMR proteins MSH2 and MLH1 in cutaneous SCCs from OTRs on azathioprine and from immunocompetent patients. (ii) Blood samples from OTRs on azathioprine with and without skin cancer were genotyped for the -6 exon 13 MSH2 polymorphism. (i) MSH2 and MLH1 protein expression was not altered in SCCs from OTRs on azathioprine and there was no difference in expression between SCCs from OTRs and immunocompetent patients. (ii) There was no association between MSH2 polymorphism genotype frequency and OTR skin cancer status. Despite previous findings in transplant-associated sebaceous carcinomas, defective MMR and the -6 exon 13 MSH2 polymorphism are unlikely to play a significant role in the development of SCC in OTRs on azathioprine.
    No preview · Article · Oct 2009 · British Journal of Dermatology
  • O R Colegio · C M Proby · J S Bordeaux · J M McGregor

    No preview · Article · May 2009 · American Journal of Transplantation
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    ABSTRACT: Before 1985, azathioprine and corticosteroids were used to suppress the immune response and prevent allograft rejection in organ transplant recipients. Since 1985, the majority of patients have received cyclosporin in combination with azathoprine and/or corticosteroids. More recently, other immunosuppressive agents have been introduced, including tacrolimus, sirolimus, and mycophenolate mofetil [1-3], which are described elsewhere in this book (see Part I).
    No preview · Article · Feb 2009 · Cancer treatment and research
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    ABSTRACT: 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.
    Preview · Article · Nov 2008 · British Journal of Cancer
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    Preview · Dataset · Oct 2008
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    ABSTRACT: Organ transplant recipients have a higher incidence of melanoma compared to the general population but the prognosis of this potentially fatal skin cancer in this group of patients has not yet been established. To address this, we undertook a multicenter retrospective analysis to assess outcome for 100 melanomas (91 posttransplant and 9 pretransplant) in 95 individuals. Data were collected in 14 specialist transplant dermatology clinics across Europe belonging to the Skin Care in Organ Transplant Patients, Europe (SCOPE) Network, and compared with age, sex, tumor thickness and ulceration status-matched controls from the American Joint Committee on Cancer (AJCC) melanoma database. Outcome for posttransplant melanoma was similar to that of the general population for T1 and T2 tumors (< or = 2 mm thickness); but was significantly worse for T3 and T4 tumors (> 2 mm thickness); all nine individuals with a pretransplant melanoma survived without disease recurrence following organ transplantation. These data have implications for both cutaneous surveillance in organ transplant recipients and management of transplant-associated melanoma.
    Full-text · Article · Sep 2008 · American Journal of Transplantation
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    J G Cronin · D Mesher · K Purdie · H Evans · J Breuer · C.A. Harwood · J M McGregor · C M Proby
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    ABSTRACT: Human papillomaviruses (HPVs) of the beta genus (beta-PV), especially HPV5 and HPV36, are proposed to play a pathogenic role in psoriasis, but many previous studies have failed to control for potential confounders, including treatment. To re-examine the relationship between beta-PV and psoriasis addressing limitations present in previous studies and analyse intra-patient concordance for carriage of HPV. Plucked eyebrow hairs and forearm skin scrapes were collected from 20 newly diagnosed, previously untreated adult patients with psoriasis and 23 normal controls. A combination of type-specific and degenerate polymerase chain reaction methods was used to achieve comprehensive HPV DNA detection. The prevalence of HPV in hair and skin from psoriasis patients was higher than in controls (83.3% vs. 46.7%, respectively, P < 0.03 corrected for age and clustering). HPV5 or HPV36 were not over-represented. The profile of diverse beta-PV types was comparable in the two groups. Intra-patient concordance for HPV DNA at separate sites was high (P < 0.00001). Our data do not support a specific causal role for HPV5 or HPV36 in psoriasis, but suggest that psoriatic skin may be more permissive for viral presence than normal skin. High intra-patient concordance for specific HPV types at separate sites, together with the ubiquity of HPV DNA in normal human skin, suggests that an individual becomes colonized with a particular beta-PV profile presumably to the exclusion of other types. To what extent this HPV profile is then causal in the subsequent development of hyperproliferative skin disease is unknown.
    Full-text · Article · Aug 2008 · British Journal of Dermatology
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    ABSTRACT: Azathioprine is used to treat a variety of conditions and to prevent graft rejection in organ transplant recipients (OTRs). To investigate clinically our previous finding that azathioprine metabolites interact with ultraviolet (UV) A radiation to form promutagenic oxidative DNA damage and to determine whether this may be causal or contributory to the development of excess skin cancers post-transplantation. The clinical corollary of these data were investigated. Five patients were recruited and the minimal erythema dose (MED) for UVB, UVA and solar-simulated radiation (SSR) was determined for each person before, and at least 12 weeks after, starting azathioprine therapy. In all five patients azathioprine treatment was associated with an increased UVA and SSR sensitivity of the skin and a significant reduction in MEDs for UVA and SSR. We found no change in UVB-induced erythema or MED. In addition, we found that DNA from the skin of patients on azathioprine contains 6-thioguanine (6-TG). Our findings confirm the presence of DNA 6-TG in the skin of those taking therapeutic doses of azathioprine and provide support for the hypothesis that DNA damage occurs when DNA 6-TG interacts with UVA, resulting in abnormal cutaneous photosensitivity.
    No preview · Article · Aug 2008 · British Journal of Dermatology

Publication Stats

4k Citations
526.42 Total Impact Points


  • 2013-2015
    • Barts Health NHS Trust
      Londinium, England, United Kingdom
  • 2005-2012
    • Queen Mary, University of London
      • • The Blizard Institute of Cell and Molecular Science
      • • Centre for Cutaneous Research
      Londinium, England, United Kingdom
  • 2005-2009
    • University of London
      • The London School of Medicine and Dentistry
      Londinium, England, United Kingdom
  • 2006
    • WWF United Kingdom
      Londinium, England, United Kingdom
  • 2001
    • St. Mark's Hospital
      Harrow, England, United Kingdom
    • St. John's Hospital
      Springfield, Illinois, United States
  • 2000
    • King's College London
      Londinium, England, United Kingdom
    • The Kings College
      Brooklyn, New York, United States
    • Beaumont Hospital
      Dublin, Leinster, Ireland
  • 1998-2000
    • Royal Cornwall Hospitals NHS Trust
      Truro, England, United Kingdom
  • 1999
    • London School of Hygiene and Tropical Medicine
      Londinium, England, United Kingdom
  • 1995
    • North Middlesex University Hospital NHS Trust
      Londinium, England, United Kingdom
  • 1994
    • Royal Free London NHS Foundation Trust
      • Department of Dermatology
      Londinium, England, United Kingdom