Multiple basal cell carcinomas in xeroderma pigmentosum treated with imiquimod 5% cream

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.

Current Therapeutic Strategies of Xeroderma Pigmentosum

Xeroderma pigmentosum (XP) is an autosomal recessive genetic disease caused by a defect in the DNA repair system, exhibiting skin cancer on sun exposure. As it is an incurable disease, therapeutic strategies of this disease are critical. This review article takes an attempt to explore the current therapeutic advancements in XP. Different approaches including sun avoidance; surgical removal of cancerous lesions; laser and photodynamic therapy; use of retinoid, 5-fluorouracil, imiquimod, photolyase, and antioxidant; interferon therapy and gene therapy are chosen by doctors and patients to lessen the adverse effects of this disease. Among these options, sun avoidance, use of 5-fluorouracil and imiquimod, and interferon therapy are effective. However, some approaches including laser and photodynamic therapy, and the use of retinoids are effective against skin cancer having severe side effects. Furthermore, surgical removal of cancerous lesions and use of antioxidants are considered to be effective against this disease; however, efficacies of these are not experimentally determined. In addition, some approaches including oral vismodegib, immunotherapy, nicotinamide, acetohexamide, glimepiride-restricted diet are found to be effective to minimize the complications secondary to defects in the nucleotide excision repair (NER) system and also enhance the NER, which are under experimental level yet. Besides these, gene therapy, including the introduction of missing genes and genome edition, may be a promising approach to combat this disease, which is also not well established now. In the near future, these approaches may be effective tools to manage XP.

Genetisch bedingte Hauterkrankungen – Xeroderma pigmentosum und das CEDNIK-Syndrom

Die Rostocker Hautklinik ist Europäisches Referenznetzwerkzentrum für seltene Hauterkrankungen mit den besonderen Schwerpunkten Xeroderma pigmentosum und Ichthyosen. Diese Themen vertreten wir auch in der medizinischen Grundlagenforschung.

Xeroderma pigmentosum (XP) ist eine seltene, autosomal-rezessive Erkrankung, die entsprechend der Gendefekte in 7 Komplementationsgruppen – XP-A bis XP-G sowie die sog. XP-Variante (XP-V) – eingeteilt wird. XP ist ein Nukleotid-Exzisions-Reparatur-Defektsyndrom und äußert sich v. a. durch vorzeitige Hautalterung und frühzeitige Entwicklung von Hauttumoren.

Das seltene, neurokutane CEDNIK-Syndrom ist eine autosomal-rezessive Erkrankung, der eine Loss-of-Function-Mutation in SNAP29 zugrunde liegt. SNAP29 ist ein SNARE-Protein und an intrazellulären Membranfusionen beteiligt. CEDNIK ist ein Akronym für den mit dem Syndrom assoziierten Symptomkomplex aus zerebraler Dysgenese, Neuropathie, Ichthyose und Palmoplantarkeratosen. CEDNIK-Patienten weisen neben der Ichthyose zudem Gedeihstörungen, eine psychomotorische Retardierung und faziale Dysmorphien auf.

Topical Imiquimod as a Treatment Option for Nodular Basal Cell Carcinoma: A Systematic Review

BACKGROUND

Surgical excision is considered standard treatment for nodular basal cell carcinoma (nBCC). However, patients who reject or are unsuited for surgery may benefit from imiquimod (IMQ) 5% cream as an alternative treatment.

OBJECTIVES

The objective of this study was to conduct a systematic review on the efficacy and safety of IMQ for the treatment of nBCC.

MATERIALS AND METHODS

The terms basal cell carcinoma AND imiquimod OR Aldara were searched on Ovid-MEDLINE, EMBASE, and Cochrane Library databases. Articles were included if they reported the efficacy or side effects of IMQ for nBCC. Primary outcomes included clearance (clinical and histological), recurrence rates, and adverse events. Number of lesions/subjects, treatment regimens, length of treatment, and time to recurrence were secondary outcomes.

RESULTS

Thirty-nine publications, totaling 738 lesions, revealed a 77.4% (335/433 lesions) clinical and 72.9% (390/535 lesions) histological clearance rate. Regimens ranged from once daily 2 days a week to twice daily 7 days a week. Average treatment duration was 8.81 (±3.49) weeks. There was a 1.80% recurrence rate after an average follow-up period of 13.03 (±15.09) months. Common adverse effects included erythema (77.2%), crusting (50.5%), pruritus (34.1%), tenderness/irritation (27.3%), ulceration (25.4%), burning (22.1%), and erosion (21.7%). Unforeseen side effects included conjunctivitis, keratitis, depigmentation, comedone formation, and ruptured epidermoid cysts.

CONCLUSION

Imiquimod showed clinical and histological clearance rates of over 70% for nBCC, with a recurrence rate of 1.80%. Although clearance rates are lower than surgery, IMQ can be considered as a treatment option for nBCC in those who decline or are unfit for surgical intervention.

Sunlight, Vitamin D, and Xeroderma Pigmentosum

Sunlight, in particular UV-B radiation, is an important factor for endogenous vitamin D production as 80-90% of the required vitamin D needs to be photosynthesized in the skin. The active form of vitamin D, vitamin D₃ or calcitriol, binds to the ligand-activated transcription factor vitamin D receptor (VDR) for genomic and non-genomic effects. Recently, calcitriol and analogs have been shown to have antiproliferative effects in mouse and human BCC and SCC cell lines in vitro. As UV radiation plays a critical role in the photosynthesis of vitamin D, stringent sun protection, as recommended for xeroderma pigmentosum (XP) patients, may impact their vitamin D levels.XP is a rare autosomal recessive disorder with a worldwide prevalence of 1 in 1,000,000. XP can be divided into seven different complementation groups: XP-A to XP-G. The complementation groups correspond with the underlying gene defect. Defects in these genes lead to a defective nucleotide excision repair (NER), which is necessary to remove UV-induced DNA damage such as the UV photoproducts cyclobutane pyrimidine dimers (CPD) and 6-4 pyrimidine-pyrimidone (6-4 PP) dimer. Additionally, a variant form with a mutation in the translational polymerase η gene (PolH), also called XP variant (XPV), exists. Patients with XPV show a defect in translesion synthesis. Due to their inability to repair UV-induced lesions, XP patients exhibit an increased risk for UV-induced nonmelanoma skin cancer (NMSC) such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) as well as melanoma. Although no curative therapy for XP exists today, numerous options for the treatment and prophylaxis of skin cancer have become available.

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.

Nonsyndromic Multiple Basal Cell Carcinomas

Basal cell carcinoma (BCC) comprising several lesions is not uncommon, but nonsyndromic multiple BCCs with parotid invasion are rare entities. We present two cases of multiple sporadic, nonsyndromic BCCs, and one of these cases is a unique case of parotid invasion associated purely with actinic keratosis. In Case 1, a 79-year-old female presented with multiple skin lesions on the face and left hand. All lesions were completely removed by surgery. The pathologic results showed lesions consistent with BCC and some lesions consistent with actinic keratosis. After 8 months, the patient presented with skin lesions in bilateral temporal areas and left cheek area. Surgical excision of the lesions was performed, and the biopsy results were squamous cell carcinoma in situ and actinic keratosis. In Case 2, a 43-year-old woman presented with multiple skin lesions on the face, scalp, right chest, abdomen and right leg. All lesions were completely removed by surgery. Pathologic evaluation confirmed the diagnosis of BCC. BCC is rarely metastatic, but it can lead to severe disfiguration or destruction. It is important to diagnose and treat BCC at an early stage.

Epidemiology of basal cell carcinoma

Basal cell carcinoma is the most common malignant neoplasm in humans and its incidence has increased over the last decades. Its high frequency significantly burdens the health system, making the disease a public health issue. Despite the low mortality rates and the rare occurrence of metastases, the tumor may be locally invasive and relapse after treatment, causing significant morbidity. Exposure to ultraviolet radiation is the main environmental risk factor associated with its cause. However, other elements of risk are described, such as light skin phototypes, advanced age, family history of skin carcinoma, light eyes and blond hair, freckles in childhood and immunosuppression. Behavioral aspects such as occupational sun exposure, rural labor and sunburns at a young age also play a role. Between 30% and 75% of the sporadic cases are associated with patched hedgehog gene mutation, but other genetic changes are also described. The tumor is commonly found in concomitance with skin lesions related to chronic sun exposure, such as actinic keratoses, solar lentigines and facial telangiectasia. The prevention of basal cell carcinoma is based on the knowledge of risk factors, early diagnosis and treatment, as well as on the adoption of specific measures, particularly in susceptible populations. The authors present a review of the epidemiology of basal cell carcinoma.

[Contribution of the cryosurgery in the management of xeroderma pigmentosum]

BACKGROUND

Basal cell carcinoma (BCC) occurs frequently in young patients with xeroderma pigmentosum (XP). Because tumours are multiple and usually found on the face, alternatives to surgery are proposed. The purpose of this study was to evaluate the efficacy of cryosurgery for BCC in XP patients.

PATIENTS AND METHODS

This was a retrospective study that included all instances of BCC occurring in XP patients treated by cryosurgery between January 2002 and October 2008.

RESULTS

Forty-five cases of primary facial BCC and one case of relapsing BCC (16 on the cheeks, 11 on the nose, six on the face and five on the inner edge of the eye area) were treated by cryosurgery in 18 XP patients (average age: 18.7 years; sex ratio: 0.5). Mean carcinoma size was 10mm. Thirty-six tumours were nodular and 10 were nodular and ulcerated. Follow-up ranged from 16 to 60 months (mean: 30 months). Complications were rare. Cosmetic results were satisfactory. We noted 10 cases of hypopigmentation (21.7%) and one notch on the nose following treatment for recurrent BCC on a radiotherapy scar. Relapse occurred in one case (2.17%).

CONCLUSION

Because of its simplicity, its good safety, its sparing of skin and its reliability of oncological outcome, cryosurgery is the treatment of choice for CBC in XP patients.