Living with xeroderma pigmentosum: comprehensive photoprotection for highly photosensitive patients

Insights from multi-omic modeling of neurodegeneration in xeroderma pigmentosum using an induced pluripotent stem cell system

Xeroderma pigmentosum (XP) is caused by defective nucleotide excision repair of DNA damage. This results in hypersensitivity to ultraviolet light and increased skin cancer risk, as sunlight-induced photoproducts remain unrepaired. However, many XP patients also display early-onset neurodegeneration, which leads to premature death. The mechanism of neurodegeneration is unknown. Here, we investigate XP neurodegeneration using pluripotent stem cells derived from XP patients and healthy relatives, performing functional multi-omics on samples during neuronal differentiation. We show substantially increased levels of 5',8-cyclopurine and 8-oxopurine in XP neuronal DNA secondary to marked oxidative stress. Furthermore, we find that the endoplasmic reticulum stress response is upregulated and reversal of the mutant genotype is associated with phenotypic rescue. Critically, XP neurons exhibit inappropriate downregulation of the protein clearance ubiquitin-proteasome system (UPS). Chemical enhancement of UPS activity in XP neuronal models improves phenotypes, albeit inadequately. Although more work is required, this study presents insights with intervention potential.

Translating patient needs into medical device development: co-design of a photoprotection visor for Xeroderma Pigmentosum using qualitative interviews

INTRODUCTION

People with Xeroderma Pigmentosum (XP) have a heightened sensitivity to ultraviolet radiation (UVR) and are advised to wear photoprotective clothing including a visor covering the face and neck. Photoprotective visors are homemade and predominately worn by children with decreasing frequency as age increases. To improve upon the current design and efficacy we were tasked with developing a prototype visor to meet patients' needs.

METHODS

Adopting a codesign methodology, patients' experiences of wearing a visor and patient and carer views of emerging prototypes were explored during interviews. A thematic analysis was conducted in parallel with data collection and themes were interpreted into design cues; desirable attributes of a visor that would counteract the negative user experiences and meet the requirements described by patients and carers. The design cues guided the iterative development of prototypes by academic engineers.

RESULTS

Twenty-four interviews were conducted with patients and carers. Thematic analysis resulted in the following five themes: Being safe from UVR exposure; self-consciousness; temperature effects; acoustic difficulties; and material properties. The following design cues were developed from the themes respectively; materials and design with high UVR protection; ability to customise with own headwear; ventilation to reduce steaming up; acoustic functionality to enable hearing and speech; foldable, portable, and easy to put on and take off.

CONCLUSIONS

It is important to understand people's experiences of using medical devices to improve their safety, efficiency and user satisfaction. The user experience themes and design cues, informed the iterative development of low fidelity visor prototypes as part of a codesign process. These design cues and responses to the prototypes are guiding commercial manufacturing and regulatory approval. The visor can then be prescribed to patients, providing an equitable service of care.

Physical, oral, and swallowing functions of three patients with type a xeroderma pigmentosum: a report of three cases

BACKGROUND

Xeroderma pigmentosum (XP) is an extremely rare and severe form of photosensitivity. It is classified into types A-G or V according to the gene responsible for the disease. The progression and severity of symptoms vary depending on the type. Although dysphagia caused by decreased swallowing function and dental malposition due to stenosis of the dentition in the facial and oral regions is common, it has not been reported in detail. We report three cases of type A XP, in which central and peripheral neurological symptoms appeared early on and progressed rapidly. We describe the oral function of these patients, focusing on the swallowing function and dentition malposition.

CASE PRESENTATION

Two males (27 and 25 years old) and one female (28 years old) presented with diverse neurological symptoms. We focused on the relationship between the changes in swallowing and oral functions and conditions due to decline in physical function. Some effects were observed by addressing the decline in swallowing and oral functions. In particular, a dental approach to manage the narrowing of the dentition, which was observed in all three patients, improved the swallowing and oral functions and maintained the current status of these functions.

CONCLUSIONS

In type A XP, early decline in oral and swallowing functions is caused by the early decline in physical function, and it is necessary to monitor the condition at an early stage.

Acceptability and influence of a complex personalized intervention on changes in photoprotection behaviours among people with xeroderma pigmentosum

OBJECTIVES

Rigorous photoprotection is the only means to prevent skin cancer in people with the rare condition of xeroderma pigmentosum (XP). We conducted a qualitative process evaluation of patient experiences and responses to a highly personalized, multi-component intervention, 'XPAND', designed to influence the psychosocial determinants of inadequate photoprotection among adults with XP.

DESIGN

Qualitative study of 15 patients following participation in a RCT.

METHODS

Semi-structured interviews explored acceptability, changes in photoprotection and attributions for behavioural changes. Analysis followed a framework approach.

RESULTS

Participants were overwhelmingly positive in their views of the quality and range of components of XPAND and the relevance to their personal photoprotection barriers. All participants reported improved adherence to at least one photoprotection activity and nearly two-thirds of participants noted improvements across multiple activities. Participants believed improvements in their photoprotection behaviours were influenced by different change mechanisms. Sunscreen application, was mainly facilitated by habit formation, prompted by text messages, whereas the wearing of a photoprotective face buff was influenced by strategies, learnt during one-to-one sessions, to overcome worry about looking different. Enhancement of general self-confidence and perceived support from XPAND described by participants facilitated change more broadly.

CONCLUSIONS

Exploration of responses to XPAND is required in the international XP population, followed by adaptation and evaluation to see if it could benefit other patient groups at higher risk of skin cancer. Implications for approaches to behaviour change include the acceptability of complex multidimensional interventions, the importance of dynamic personalization and the interactive nature of behaviour change mechanisms.

Retrospective study of efficacy and adverse events of immune checkpoint inhibitors in 22 xeroderma pigmentosum patients with metastatic or unresectable cancers

Background

Xeroderma pigmentosum (XP), a rare disease with defects in DNA repair genes, has >1,000-fold increased risk of ultraviolet-induced skin cancers. Immune checkpoint inhibitors (ICIs) are used for treating cancers with large numbers of mutations but may also promote adverse events (AEs). Deficient DNA repair in XP patients may lead to increased numbers of mutations, leading to enhanced efficacy of cancer response or, alternatively, to increased AE in response to ICI. We sought to compare the efficacy and AE of ICI in XP patients with metastatic or unresectable cancers to that of ICI-treated patients in the general population.

Methods

In this retrospective study, we reviewed medical records of XP patients treated in the United States and in London (UK). We also reviewed published reports of ICI-treated XP patients and patients in the general population.

Results

Metastatic or unresectable cancers in all 22 (100%) XP patients showed regression or remission in response to ICI. The types and frequencies of AE in XP patients were similar to those reported among ICI-treated patients in the general population. However, two XP patients had concurrent additional cancers that did not respond to ICI, two XP patients had cancer recurrence or progression after initial response, and eight XP patients developed new skin cancers during or after ICI treatment.

Conclusion

In this retrospective study with small sample size, XP patients demonstrated positive responses to ICI and the treatment was well tolerated but some patients developed new skin cancers while being treated. ICIs can be considered in treating metastatic or unresectable cancers in XP patients.

Xeroderma pigmentosum: case report

OBJECTIVE

The aim of this study was to describe the disease and treatment and to alert health professionals for the identification of signs and symptoms and the need for an early diagnosis in patients with xeroderma pigmentosum (XP).

CASE DESCRIPTION

An 8-year-old male patient was referred to the Joana de Gusmão Hospital (HIJG) in 2021 for evaluation and specialized care. Previously, the child was followed in his place of origin by oncologic and palliative care, where he was submitted to surgeries and chemotherapy. He was admitted to the HIJG using vismodegib, acitrein, tramadol, and solar protective measures. On physical examination, there were tumors and disseminated macular verrucous and ulcerated lesions. The imaging examination showed solid and expansive lesions on the face, and atelectasis and fibroscarring changes in the lung. The histopathological report proved the existence of melanocanthoma, carcinoma, and pyogenic granuloma. After the evaluation of the case, no surgery, chemotherapy, or radiotherapy was performed. It was decided to maintain the palliative treatment and to continue the use of tramadol for pain, and vismodegib and acitretin were used to control carcinomas and prophylactic measures.

COMMENTS

The XP is a rare disease of autosomal recessive inheritance whose mechanism comes from failure in the DNA repair by exposure to ultraviolet rays, resulting in lesions on the skin and mucous membranes. They start as sunburns and can progress to melanosis, areas with altered pigmentation, premature aging, poikiloderma, and areas of high risk for neoplasms.

A matter of delicate balance: Loss and gain of Cockayne syndrome proteins in premature aging and cancer

DNA repair genes are critical for preserving genomic stability and it is well established that mutations in DNA repair genes give rise to progeroid diseases due to perturbations in different DNA metabolic activities. Cockayne Syndrome (CS) is an autosomal recessive inheritance caused by inactivating mutations in CSA and CSB genes. This review will primarily focus on the two Cockayne Syndrome proteins, CSA and CSB, primarily known to be involved in Transcription Coupled Repair (TCR). Curiously, dysregulated expression of CS proteins has been shown to exhibit differential health outcomes: lack of CS proteins due to gene mutations invariably leads to complex premature aging phenotypes, while excess of CS proteins is associated with carcinogenesis. Thus it appears that CS genes act as a double-edged sword whose loss or gain of expression leads to premature aging and cancer. Future mechanistic studies on cell and animal models of CS can lead to potential biological targets for interventions in both aging and cancer development processes. Some of these exciting possibilities will be discussed in this review in light of the current literature.

Identifying the psychosocial predictors of ultraviolet exposure to the face in patients with xeroderma pigmentosum: a study of the behavioural factors affecting clinical outcomes in this genetic disease

Background

For patients with xeroderma pigmentosum (XP), the main means of preventing skin and eye cancers is extreme protection against ultraviolet radiation (UVR), particularly for the face. We have recently developed a methodology for objectively measuring photoprotection behaviour (‘UVR dose to facial skin’) and have found that the degree of photoprotection varies greatly between patients with XP. We have previously identified factors affecting photoprotection behaviour in XP using a subjective measure of photoprotection. Here, we have used this objective methodology to identify the factors which determine photoprotection behaviour in XP.

Methods

We studied 29 psychological, social, demographic and clinical variables in 36 patients with XP. We have previously objectively measured UVR protection (by measuring the dose of UVR reaching the skin of the face over a 3-week period) in these patients. Here, we use linear mixed-effects model analysis to identify the factors which lead to the differences in degree of photoprotection observed in these patients.

Results

Psychosocial factors accounted for as much of the interindividual variation in photoprotection behaviour (29%) as demographic and clinical factors (24%). Psychosocial factors significantly associated with worse UVR protection included: automaticity of the behaviours, and a group of beliefs and perceptions about XP and photoprotection known to associate with poor treatment adherence in other diseases.

Conclusions

We have identified factors contributing to poor photoprotection in XP. Identifying these potentially reversible psychosocial features has enabled us to design an intervention to improve photoprotection in patients with XP, aiming to prevent skin and eye cancers in these patients.

Potential UV-Protective Effect of Freestanding Biodegradable Nanosheet-Based Sunscreen Preparations in XPA-Deficient Mice

Xeroderma pigmentosum (XP) is a rare autosomal recessive hereditary disorder. As patients with XP are deficient in nucleotide excision repair, they show severe photosensitivity symptoms. Although skin protection from ultraviolet (UV) radiation is essential to improve the life expectancy of such patients, the optimal protective effect is not achieved even with sunscreen application, owing to the low usability of the preparations. Nanosheets are two-dimensional nanostructures with a thickness in the nanometer range. The extremely large aspect ratios of the nanosheets result in high transparency, flexibility, and adhesiveness. Moreover, their high moisture permeability enables their application to any area of the skin for a long time. We fabricated preparations containing avobenzone (BMDBM) based on freestanding poly (L-lactic acid) (PLLA) nanosheets through a spin-coating process. Although monolayered PLLA nanosheets did not contain enough BMDBM to protect against UV radiation, the layered nanosheets, consisting of five discrete BMDBM nanosheets, showed high UV absorbance without lowering the adhesive strength against skin. Inflammatory reactions in XPA-deficient mice after UV radiation were completely suppressed by the application of BMDBM-layered nanosheets to the skin. Thus, the BMDBM layered nanosheet could serve as a potential sunscreen preparation to improve the quality of life of patients with XP.

Xeroderma Pigmentosum with Simultaneous Cutaneous and Ocular Squamous Cell Carcinoma

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease that disrupts deoxyribonucleic acid (DNA) repair due to ultraviolet (UV) radiation. XP is characterized by extreme sensitivity to sunlight, photophobia, cutaneous lesions in the form of freckle-like hyperpigmented macules, and neoplasia on the skin surface. Malignancy is a common complication found in areas exposed to UV light. Squamous cell carcinomas (SCC) is the most common malignancy seen in patients with XP. This report illustrates a case of XP in a six-year-old girl with cutaneous and ocular SCC. The diagnosis of XP was established based on the patient’s history and the presence of typical clinical manifestations. Dermoscopy and histopathology examinations confirmed the presence of SCC on the face and eyes. The management of XP patients includes early diagnosis, lifelong UV protection, and early detection of cutaneous malignancy. Early detection and appropriate management are very important in preventing the occurrence of malignancy.

Ultraviolet exposure to the face in patients with xeroderma pigmentosum and healthy controls: applying a novel methodology to define photoprotection behaviour

BACKGROUND

In Xeroderma Pigmentosum (XP), the main means of preventing skin and eye cancers is extreme protection against ultraviolet radiation (UVR). Protection is most important for the face.

OBJECTIVES

We aimed to assess how well patients with XP adhere to medical advice to protect against UVR by objectively estimating the mean daily dose of UVR to the face.

METHODS

We objectively estimated the UVR dose to the face in 36 XP patients and 25 healthy individuals over 3 weeks in the summer. We used a new methodology which combined UVR dose measurements from a wrist-worn dosimeter with an activity diary record of face photoprotection behaviour for each 15 minute period spent outside. A protection factor was associated with each behaviour, and the data analysed using a negative binomial mixed-effects model.

RESULTS

The mean daily UVR dose (weighted for DNA damage capacity) to the face in the XP patients was 0.13 Standard Erythemal Doses (SED) (mean in healthy individuals = 0.51 SED). There was wide variation between patients (range <0.01 - 0.48 SED/day). Self-caring adult patients had a very similar UV dose to the face to cared-for patients (0.13 vs 0.12 SED/day) despite photoprotecting much more poorly when outside, because the self-caring adults were outside in daylight much less.

CONCLUSIONS

Photoprotection behaviour varies widely within the XP group indicating that non-adherence to photoprotection advice is a significant issue. Timing and duration of going outside are as important as photoprotective measures taken when outside, to determine the UVR exposure to the face. This new methodology will be of value in identifying the sources of UVR exposure in other conditions where facial UV exposure is a key outcome, particularly in patients with multiple non-melanoma skin cancers.

Xeroderma Pigmentosum: General Aspects and Management

Xeroderma Pigmentosum (XP) is a rare genetic syndrome with a defective DNA nucleotide excision repair. It is characterized by (i) an extreme sensitivity to ultraviolet (UV)-induced damages in the skin and eyes; (ii) high risk to develop multiple skin tumours; and (iii) neurologic alterations in the most severe form. To date, the management of XP patients consists of (i) early diagnosis; (ii) a long-life protection from ultraviolet radiation, including avoidance of unnecessary UV exposure, wearing UV blocking clothing, and use of topical sunscreens; and (iii) surgical resections of skin cancers. No curative treatment is available at present. Thus, in the last decade, in order to prevent or delay the progression of the clinical signs of XP, numerous strategies have been proposed and tested, in some cases, with adverse effects. The present review provides an overview of the molecular mechanisms featuring the development of XP and highlights both advantages and disadvantages of the clinical approaches developed throughout the years. The intention of the authors is to sensitize scientists to the crucial aspects of the pathology that could be differently targeted. In this context, the exploration of the process underlining the conception of liposomal nanocarriers is reported to focus the attention on the potentialities of liposomal technology to optimize the administration of chemoprotective agents in XP patients.

Thyroid nodules in xeroderma pigmentosum patients: a feature of premature aging

PURPOSE

Xeroderma pigmentosum (XP) is an autosomal recessive disease with defective DNA repair, a markedly increased risk of skin cancer, and premature aging. Reports from North Africa have described thyroid nodules in XP patients, but thyroid nodule prevalence has never been determined in XP patients enrolled in our natural history study at the National Institutes of Health (NIH).

METHODS

We performed thyroid ultrasound examinations on all 29 XP patients examined from 2011 to 2019 and assessed nodule malignancy using the Thyroid Imaging Reporting and Data System. Thyroid nodule prevalence was also obtained from comparison cohorts. DNA sequencing was performed on thyroid tissue from XP patients who had surgery for thyroid cancer.

RESULTS

Thyroid nodules were identified in 18/29 XP patients (62%). The median age of patients with thyroid nodules in our XP cohort (20 years) was younger than that of three comparison groups: 36 years (California study-208 subjects), 48 years (Korean study-24,757 subjects), and 52 years (NIH-682 research subjects). Multiple (2-4) thyroid nodules were found in 12/18 (67%) of the patients with nodules. Autopsy examination revealed follicular adenomas in 4/8 (50%) additional XP patients. DNA sequencing revealed rare mutations in two other XP patients with papillary thyroid cancer.

CONCLUSIONS

XP patients have an increased incidence of thyroid nodules at an early age in comparison to the general population. These finding confirm another premature aging feature of XP.

Therapeutics of xeroderma pigmentosum: A PRISMA-compliant systematic review

Xeroderma pigmentosum is a rare hereditary autosomal recessive genodermatosis. At present, there are many treatment options for xeroderma pigmentosum, covering medical/procedural, surgical and combined modalities. However, the quality of these interventions has not been assessed. Our study aimed to perform a systematic review of the literature regarding the treatment of xeroderma pigmentosum. Multiple medical databases were accessed with the Medical Subject Headings terms; "xeroderma pigmentosum," "therapeutics" and "surgical procedures, operative" from January 2000 to April 2019, including articles published in Portuguese, Spanish and English (PROSPERO-CRD42018114858). Two hundred and ninety-eight studies were found in the databases researched, of which, after applying the inclusion criteria, only 33 studies remained. The 33 complete articles were read by three of the authors, having been found: 16 reported medical/procedural and 17 reported surgical treatments. Only one clinical study presented a good level of evidence (EL: 2): a randomized clinical trial using a T4 endonuclease V (T4N5) liposome lotion which reduced the development of skin lesions in patients with xeroderma pigmentosum. Amongst surgical modalities, all studies presented low evidence level (EL: 4). Three illustrative cases are also presented, to emphasize the multiple number of times that surgical modalities may be required in these patients. The therapeutic modalities, both clinical and surgical, for xeroderma pigmentosum presented a low level of scientific evidence which did not allow meta-analysis. More therapeutic studies, both clinical and surgical, with better scientific evidence are needed.

Improving photoprotection in adults with xeroderma pigmentosum: personalisation and tailoring in the 'XPAND' intervention

BACKGROUND

Individualised behaviour change interventions can result in greater effects than one-size-fits-all approaches. Factors linked to success include dynamic (vs. static) tailoring, and tailoring on behaviour, multiple theoretical variables, and participant characteristics. XP is a very rare (∼100 UK patients) genetic disease, involving an inability to repair ultraviolet radiation (UVR)-induced damage, resulting in skin cancers and eye damage from an early age, and mean life expectancy of 32-years. Management involves rigorous UVR photoprotection, which is often inadequate, and no interventions have been published. UK-based care is personalised and delivered by a multidisciplinary team at the National XP Service in London. Following an intensive, mixed-methods formative phase with patients diagnosed with XP (n-of-1, qualitative interviews, objective UVR measurement, cross-sectional survey) and relevant stakeholder consultation (clinical and patient/public teams), the 'XPAND' intervention was developed. This paper describes the comprehensive and novel tailoring and personalisation processes used to deliver the intervention.

METHODS

XPAND consists of core and personalised modules targeting cue-based (time of day, weather, symptoms), belief-based (motivation, priority), self-regulatory (effort, barriers, planning), and emotional (stress, self-consciousness, mental exhaustion) factors, social support, disclosure, habit, and willingness, using appropriately-matched BCTs. A-priori, phase I data and a baseline profiling questionnaire (data sources) were used to allocate modules to participants ('personalisation') and to adapt module content ('tailoring'). Iterative decisions about delivery were based on patient response to feedback, identification of additional barriers (e.g. reasons for varying protection across contexts), and emergence of new barriers as improvements in protection were attempted or achieved (e.g. appearance concerns).

CONCLUSIONS

Dynamic multi-level personalisation and tailoring based on mixed-methods in XPAND allowed for insights and decision-making not possible with cross-sectional quantitative or qualitative methods alone. Data collection and allocation/adaptation methods may be of use in other rare conditions where small patient numbers mean that within-participant, individual-level delivery is well-suited and feasible.

Approaches to Photoprotection and Normalization in Highly Adherent Families of Children With Xeroderma Pigmentosum in the United Kingdom

In this study, we examine photoprotection for children with Xeroderma pigmentosum (XP), a rare genetic skin disease requiring rigorous photoprotection, to reduce risks of severe burning and skin cancers from exposure to ultraviolet radiation (UVR). We elicit the views and experiences of both children and their parents to inform the care and support provided. Qualitative semistructured interviews were undertaken with 12 child-parent dyads recruited from the National XP Specialist service in London. We employed a framework approach to analysis. This identified a high level of photoprotection based either on "protection" to facilitate normal activities or "avoidance" of outdoor activity with priority given to normality in the future. These approaches were shaped by perceptions of clinical risk, the emphasis given to a normal family life and families' circumstances and resources. The findings contribute to notions of normalization and coping with demanding care regimens and inform approaches to working with families.

Novel mutation identified in the DDB2 gene in patients with xeroderma pigmentosum group-E

BACKGROUND

Xeroderma pigmentosum (XP) is a rare photosensitive syndrome, which is divided into eight complementation groups (XP-A to XP-G and XPV) and characterized by skin cancers diagnosed at early age. A family of seven members (age range between 5 and 47 years) with carriers of the novel nonsense mutation that causes XP-E type were included in the current study.

METHODS

DNA was isolated from peripheral blood samples of the proband, and cancer predisposition genes were sequenced with next-generation sequencing. The demographic features and the laboratory, clinical, and histopathological findings of patients were evaluated.

RESULTS

In the proband, squamous cell carcinoma was first diagnosed in the right-eye cornea at the age of 13 years and then in the left-eye cornea at the age of 15 years. Later, the patient was diagnosed with basosquamous cell carcinoma on the dorsum of the nose at the age of 18 years. After genetic analysis, a novel nonsense c.1063C>T(p.Arg355Ter) pathogenic variation that causes XP-E type was detected as homozygous in the DDB2 gene of the proband and her siblings, 11 and 5 years of age, and as heterozygous in her parents and a 22-year-old brother.

CONCLUSION

Because of the occurrence of early termination codon, truncated nonfunctional proteins or proteins with deleterious loss or gain-of-function activities are synthesized in nonsense mutation. Thus, to avoid the development of pathological lesions, it is important that such patients with nonsense mutation stay away from agents that might cause DNA damage and develop an appropriate lifestyle according to this condition.

Reproductive Health in Xeroderma Pigmentosum: Features of Premature Aging

OBJECTIVE

To assess the age at menarche and menopause of women with xeroderma pigmentosum, a DNA repair disease with premature aging, in a longitudinal natural history study.

METHODS

We conducted a natural history study that reviewed medical records for gynecologic and reproductive health of all female patients with xeroderma pigmentosum aged older than 9 years examined at the National Institutes of Health (NIH). We performed gynecologic and laboratory examinations on a subset of the patients. Women in a second subset, who could not be examined, were interviewed using a questionnaire. Women who were deceased or lost to follow-up formed a third subset.

RESULTS

Sixty females with xeroderma pigmentosum aged older than 9 years (median 29 years, range 10-61 years) were evaluated at the NIH from 1971 to 2018. Of these 60, 31 had history, questionnaire, record review, and gynecologic evaluation; 14 had record review and questionnaire interview by telephone; and 15 had only NIH record review. Menarche in females with xeroderma pigmentosum occurred at a median age of 12.0 years (range 9-17 years), which was comparable with the U.S. general population. Among the 18 patients with menopause, the median age at menopause of 29.5 years (range 18-49.5 years) was more than 20 years younger than in the U.S. general population (52.9 years). Premature menopause (before age 40 years) occurred in 14 of the 45 (31%) women aged 18 years or older, and primary ovarian insufficiency was documented in nine of them. There were 32 live births among 21 of the women, five of whom subsequently developed premature menopause.

CONCLUSION

Females with xeroderma pigmentosum in our study had a normal age at menarche and were fertile but had increased incidence of premature menopause. Premature menopause, a symptom of premature aging, should be considered for gynecologic and reproductive health as well as implicating DNA repair in maintaining normal ovarian function.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT00001813.

Compare and contrast: pediatric cancer versus adult malignancies

Cancer is a leading cause of death in both adults and children, but in terms of absolute numbers, pediatric cancer is a relatively rare disease. The rarity of pediatric cancer is consistent with our current understanding of how adult malignancies form, emphasizing the view of cancer as a genetic disease caused by the accumulation and selection of unrepaired mutations over time. However, considering those children who develop cancer merely as stochastically "unlucky" does not fully explain the underlying aetiology, which is distinct from that observed in adults. Here, we discuss the differences in cancer genetics, distribution, and microenvironment between adult and pediatric cancers and argue that pediatric tumours need to be seen as a distinct subset with their own distinct therapeutic challenges. While in adults, the benefit of any treatment should outweigh mostly short-term complications, potential long-term effects have a much stronger impact in children. In addition, clinical trials must cope with low participant numbers when evaluating novel treatment strategies, which need to address the specific requirements of children.

Psychological correlates of adherence to photoprotection in a rare disease: International survey of people with Xeroderma Pigmentosum

OBJECTIVES

Xeroderma pigmentosum (XP) is an extremely rare genetic disorder (approximately 100 known cases in the United Kingdom), where DNA damage caused by ultraviolet radiation in daylight cannot be repaired. Adherence to photoprotection is essential to prevent skin cancer. We investigated psychological correlates of photoprotection in the XP population of Western Europe and the United States.

DESIGN

Cross-sectional survey of adults with XP and caregivers of patients <16 years and those with cognitive impairment in the United Kingdom, Germany, the United States, and France (n = 156).

METHODS

Photoprotection activities to protect the face and body when outdoors; avoidance of going outside during daylight hours; intention; self-efficacy; and social support were assessed using measures developed for this study. Participants answered questions about their illness representations of XP (BIPQ); beliefs about photoprotection (BMQ); automaticity (i.e., without conscious effort) (SRBAI); clinical and demographic characteristics. Ordinal logistic regressions determined factors associated with photoprotection.

RESULTS

One third did not achieve optimal face photoprotection. After controlling for demographic and clinical factors, modifiable correlates of higher photoprotection included greater perceived control of XP, stronger beliefs in necessity and effectiveness of photoprotection, and higher intention. Avoidance of going outside was associated with greater photoprotection concerns, more serious illness consequences, and higher XP-related distress. Greater automaticity and higher self-efficacy were associated with better protection across all outcomes.

CONCLUSIONS

Approximately half of all known cases across three European countries participated. Identified modifiable predictors of photoprotection may be targeted by interventions to reduce the incidence of skin cancers in the immediate future, when a treatment breakthrough is unlikely. Statement of contribution What is already known on this subject? Adherence to photoprotection in other populations at elevated risk from skin cancer is poor; however, the level in XP is unknown. Research across chronic conditions shows that adherence to treatment and lifestyle recommendations are influenced by illness perceptions, self-efficacy, and treatment beliefs. Studies on photoprotection conducted with the general population have found that perceived risk, perceptions of ultraviolet radiation (UVR) protection, self-efficacy for the behaviour, and automaticity (behaviours that are enacted with little conscious awareness) are related to better photoprotection. What does this study add? This is the first international survey to examine adherence and its correlates in people with XP (an under-researched group at very high risk of fatal skin cancer). Adherence varies and at least one third have potential for improvement. Perceptions about XP, photoprotection beliefs, self-efficacy, intention, and automaticity were associated with photoprotection of the face and body when outdoors. Negative emotional representations of XP were associated with avoidance of going outside during daylight hours.

Nucleolar and Ribosomal Dysfunction-A Common Pathomechanism in Childhood Progerias?

The nucleolus organizes around the sites of transcription by RNA polymerase I (RNA Pol I). rDNA transcription by this enzyme is the key step of ribosome biogenesis and most of the assembly and maturation processes of the ribosome occur co-transcriptionally. Therefore, disturbances in rRNA transcription and processing translate to ribosomal malfunction. Nucleolar malfunction has recently been described in the classical progeria of childhood, Hutchinson-Gilford syndrome (HGPS), which is characterized by severe signs of premature aging, including atherosclerosis, alopecia, and osteoporosis. A deregulated ribosomal biogenesis with enlarged nucleoli is not only characteristic for HGPS patients, but it is also found in the fibroblasts of "normal" aging individuals. Cockayne syndrome (CS) is also characterized by signs of premature aging, including the loss of subcutaneous fat, alopecia, and cataracts. It has been shown that all genes in which a mutation causes CS, are involved in rDNA transcription by RNA Pol I. A disturbed ribosomal biogenesis affects mitochondria and translates into ribosomes with a reduced translational fidelity that causes endoplasmic reticulum (ER) stress and apoptosis. Therefore, it is speculated that disease-causing disturbances in the process of ribosomal biogenesis may be more common than hitherto anticipated.

The influence of perceived medical risks and psychosocial concerns on photoprotection behaviours among adults with xeroderma pigmentosum: a qualitative interview study in the UK

BACKGROUND

A high level of photoprotection is required by people with xeroderma pigmentosum (XP), a rare skin disease, to reduce skin cancer and other risks. However poor photoprotection is thought to be widespread.

PURPOSE

This study examines the influences on photoprotection behaviours in adults with XP.

DESIGN

Inductive qualitative study with semistructured interviews. Analysis employed a framework approach.

SETTING

National sample recruited through a specialist XP centre in London.

METHODS

Semistructured interviews at patients' homes. All transcripts were coded and themes charted for each participant. Comparisons within and across cases identified common themes and differing motivations and approaches to photoprotection. Credibility of interpretations assessed through patient/carer input and clinic adherence scores.

PARTICIPANTS

25 adults (17 male, eight female) aged 16-63 years with diagnosed XP attending a specialist centre. 18 lived outside London.

RESULTS

Awareness of risks of ultraviolet radiation (UVR) and photoprotection was high. However, photoprotection behaviours varied according to perceived necessity and concerns. Three behavioural responses were identified: (1) 'dominated' by planning and routines to achieve a high level of photoprotection with significant activity restrictions and psychosocial impacts. (2) 'resistant' to photoprotection with priority given to avoiding an illness identity and enjoying a normal life. (3) Photoprotection' integrated' with an individual's life with little psychosocial impact. These responses were influenced by illness, personal and contextual factors including age, life stage and social support. Only the 'integrated' group achieved an equilibrium between perceived 'necessity' and 'concerns'.

CONCLUSIONS

The personal balance between perceived risks of UVR and social/psychological 'concerns' led to differing behavioural responses and contributes to an understanding of adaptation and normalisation in chronic illness. The study will also inform a series of individualised behavioural interventions to reduce measured UVR exposure among people with XP that are potentially applicable to other conditions with high risks of skin cancer.

Xeroderma pigmentosum: overview of pharmacology and novel therapeutic strategies for neurological symptoms

Xeroderma pigmentosum (XP) encompasses a group of rare diseases characterized in most cases by malfunction of nucleotide excision repair (NER), which results in an increased sensitivity to UV radiation in affected individuals. Approximately 25-30% of XP patients present with neurological symptoms, such as sensorineural deafness, mental deterioration and ataxia. Although it is known that dysfunctional DNA repair is the primary pathogenesis in XP, growing evidence suggests that mitochondrial pathophysiology may also occur. This appears to be secondary to dysfunctional NER but may contribute to the neurodegenerative process in these patients. The available pharmacological treatments in XP mostly target the dermal manifestations of the disease. In the present review, we outline how current understanding of the pathophysiology of XP could be used to develop novel therapies to counteract the neurological symptoms. Moreover, the coexistence of cancer and neurodegeneration present in XP led us to focus on possible new avenues targeting mitochondrial pathophysiology. LINKED ARTICLES: This article is part of a themed section on Mitochondrial Pharmacology: Featured Mechanisms and Approaches for Therapy Translation. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.22/issuetoc.

Recent Developments in the Diagnosis and Management of Photosensitive Disorders

Photodermatoses occur in males and females of all races and ages. Onset can be variable in timing and influenced by genetic and environmental factors. Photodermatoses are broadly classified as immunologically mediated, chemical- and drug-induced, photoaggravated, and genetic (defective DNA repair or chromosomal instability) diseases. Advances in the field have led to improved recognition and treatment of many photodermatoses. The purpose of this focused review is to provide an update on the diagnosis and management of a variety of photodermatoses, both common and less common, with review of recent updates in the literature pertaining to their diagnosis and management.

Malignant skin tumors: Kids are not just little people

Skin tumors are a clinically heterogeneous group of dermatologic conditions that affect both children and adults. Although similar types of skin tumors can affect both children and adults, the epidemiology, pathogenesis, and treatment of these skin neoplasms can vary drastically in children compared with adults. Despite the clear need for literature elucidating the differences of skin tumors in children compared with adults, there is a serious dearth of scientific contributions addressing this area. This contribution highlights the types of differences that can occur between adults and children with skin neoplasms, as well as the special considerations that need to be recognized when managing skin tumors in children by providing a comparative analysis of basal cell carcinoma, squamous cell carcinoma, and Kaposi sarcoma occurring in adults with these same tumors occurring in children. Specifically, we examine the aforementioned tumors with a focus on (1) epidemiology, (2) etiology, (3) clinical presentation, (4) workup, and (5) treatment.

XRCC1 and XPD polymorphisms and their relation to the clinical course in hepatocarcinoma patients

In this study genotyping of hepatocellular carcinoma (HCC) patients was conducted to detect polymorphisms on the X-ray repair cross-complementing 1 (XRCC1) and xeroderma pigmentosum complementary group D (XPD) genes and analyze the relationship of their presence with the clinical features of the cancer. A total of 172 patients with HCC were selected in Qilu Hospital, Shandong University, from January 2010 to September 2011. All patients underwent resection of HCC and no tumor metastases were found. Peripheral venous blood samples (3–5 ml) were collected from the patients to extract genomic DNA. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and gene sequencing. During the five-year follow-up, the survival of patients with various genotypes of XRCC1 and XPD genes were observed and compared. Logistic regression analysis was used to analyze the association between single nucleotide polymorphisms of XRCC1 and XPD genes and the prognosis of patients with HCC. χ² tests showed that XRCC1-194, XRCC1-280 and XPD-312 gene polymorphisms were significantly correlated with the number, location and diameter of the tumors (p<0.05). No significant difference was found in the survival curve of patients presenting different genotypes of the XRCC1-194 locus (p>0.05). Nevertheless, a significant difference was found in the survival curve of patients with AA and GG genotypes of the XRCC1-280 locus and in the patients with AA, GA and GG genotypes of the XPD-312 locus (p<0.05). Logistic regression analysis showed that the XRCC1-194 genotype was not an independent risk factor for HCC mortality risk (p>0.05), but XRCC1-280 (OR=1.815, p<0.01) and XPD-312 (OR=1.815, p<0.01) genotypes were independent risk factors for a poor prognosis. Taken together our results point to polymorphisms in XRCC1 and XPD genes as being related to the clinical characteristics of HCC, making them suitable prognostic markers of HCC.

Understanding photodermatoses associated with defective DNA repair: Photosensitive syndromes without associated cancer predisposition

Photodermatoses associated with defective DNA repair are a group of photosensitive hereditary skin disorders. In this review, we focus on diseases and syndromes with defective nucleotide excision repair that are not accompanied by an increased risk of cutaneous malignancies despite having photosensitivity. Specifically, the gene mutations and transcription defects, epidemiology, and clinical features of Cockayne syndrome, cerebro-oculo-facial-skeletal syndrome, ultraviolet-sensitive syndrome, and trichothiodystrophy will be discussed. These conditions may also have other extracutaneous involvement affecting the neurologic system and growth and development. Rigorous photoprotection remains an important component of the management of these inherited DNA repair-deficiency photodermatoses.

Xeroderma Pigmentosum

Xeroderma pigmentosum (XP) is a rare disorder of defective UV-radiation induced damage repair that is characterized by photosensitivity with easy skin burning following minimal sun exposure, early freckling and development of lentiginous pigmentation along with other features of poikiloderma and a propensity for developing skin cancer at an early age. In this short review, the clinical, pathological, genetic and molecular aspects of XP are reviewed in the current literature. XP encompasses a spectrum of disease that overlaps with other diseases of DNA repair systems. In addition to cutaneous complications, patients are susceptible to eye conditions, neurodegenerative processes, central nervous system tumors and other tumors as a result of UV radiation exposure and its byproducts. Patients with XP frequently experience a shorter life span due to skin cancer and neurodegenerative sequelae, but aggressive preventative measures to minimize UV radiation exposure and damage can improve the course of disease and prolong life. The disease has served as a model for photoaging and UV radiation-induced cancer and has led to a better understanding of cell processes that prevent development of these disease features in normal individuals.

Genome Instability in Development and Aging: Insights from Nucleotide Excision Repair in Humans, Mice, and Worms

DNA damage causally contributes to aging and cancer. Congenital defects in nucleotide excision repair (NER) lead to distinct cancer-prone and premature aging syndromes. The genetics of NER mutations have provided important insights into the distinct consequences of genome instability. Recent work in mice and C. elegans has shed new light on the mechanisms through which developing and aging animals respond to persistent DNA damage. The various NER mouse mutants have served as important disease models for Xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD), while the traceable genetics of C. elegans have allowed the mechanistic delineation of the distinct outcomes of genome instability in metazoan development and aging. Intriguingly, highly conserved longevity assurance mechanisms respond to transcription-blocking DNA lesions in mammals as well as in worms and counteract the detrimental consequences of persistent DNA damage. The insulin-like growth factor signaling (IIS) effector transcription factor DAF-16 could indeed overcome DNA damage-driven developmental growth delay and functional deterioration even when DNA damage persists. Longevity assurance mechanisms might thus delay DNA damage-driven aging by raising the threshold when accumulating DNA damage becomes detrimental for physiological tissue functioning.

Development of effective skin cancer treatment and prevention in xeroderma pigmentosum

Xeroderma pigmentosum (XP) is a rare, recessively transmitted genetic disease characterized by increasingly marked dyspigmentation and xerosis (dryness) of sun-exposed tissues, especially skin. Skin cancers characteristically develop in sun-exposed sites at very much earlier ages than in the general population; these are often multiple and hundreds or even thousands may develop. Eight complementation groups have been identified. Seven groups, XP-A…G, are associated with defective genes encoding proteins involved in the nucleotide excision DNA repair (NER) pathway that recognizes and excises mutagenic changes induced in DNA by sunlight; the eighth group, XP-V, is associated with defective translesion synthesis (TLS) bypassing such alterations. The dyspigmentation, xerosis and eventually carcinogenesis in XP patients appear to be due to their cells' failure to respond properly to these mutagenic DNA alterations, leading to mutations in skin cells. A subset of cases, especially those in some complementation groups, may develop neurological degeneration, which may be severe. However, in most XP patients, in the past the multiple skin cancers have led to death at an early age due to either metastases or sepsis. Using either topical 5-fluorouracil or imiquimod, we have developed a protocol that effectively prevents most skin cancer development in XP patients.

Comparison of mice with accelerated aging caused by distinct mechanisms

Aging is the primary risk factor for numerous chronic, debilitating diseases. These diseases impact quality of life of the elderly and consume a large portion of health care costs. The cost of age-related diseases will only increase as the world's population continues to live longer. Thus it would be advantageous to consider aging itself as a therapeutic target, potentially stemming multiple age-related diseases simultaneously. While logical, this is extremely challenging as the molecular mechanisms that drive aging are still unknown. Furthermore, clinical trials to treat aging are impractical. Even in preclinical models, testing interventions to extend healthspan in old age are lengthy and therefore costly. One approach to expedite aging studies is to take advantage of mouse strains that are engineered to age rapidly. These strains are genetically and phenotypically quite diverse. This review aims to offer a comparison of several of these strains to highlight their relative strengths and weaknesses as models of mammalian and more specifically human aging. Additionally, careful identification of commonalities among the strains may lead to the identification of fundamental pathways of aging.