Dose response of retinol and isotretinoin in the prevention of nonmelanoma skin cancer recurrence

The pathogenic role of retinoid nuclear receptor signaling in cancer and metabolic syndromes

The retinoid nuclear receptor pathway, activated by the vitamin A metabolite retinoic acid, has been extensively investigated for over a century. This study has resulted in conflicting hypotheses about how the pathway regulates health and how it should be pharmaceutically manipulated. These disagreements arise from a fundamental contradiction: retinoid agonists offer clear benefits to select patients with rare bone growth disorders, acute promyelocytic leukemia, and some dermatologic diseases, yet therapeutic retinoid pathway activation frequently causes more harm than good, both through acute metabolic dysregulation and a delayed cancer-promoting effect. In this review, we discuss controlled clinical, mechanistic, and genetic data to suggest several disease settings where inhibition of the retinoid pathway may be a compelling therapeutic strategy, such as solid cancers or metabolic syndromes, and also caution against continued testing of retinoid agonists in cancer patients. Considerable evidence suggests a central role for retinoid regulation of immunity and metabolism, with therapeutic opportunities to antagonize retinoid signaling proposed in cancer, diabetes, and obesity.

A review of deep learning-based multiple-lesion recognition from medical images: classification, detection and segmentation

Deep learning-based methods have become the dominant methodology in medical image processing with the advancement of deep learning in natural image classification, detection, and segmentation. Deep learning-based approaches have proven to be quite effective in single lesion recognition and segmentation. Multiple-lesion recognition is more difficult than single-lesion recognition due to the little variation between lesions or the too wide range of lesions involved. Several studies have recently explored deep learning-based algorithms to solve the multiple-lesion recognition challenge. This paper includes an in-depth overview and analysis of deep learning-based methods for multiple-lesion recognition developed in recent years, including multiple-lesion recognition in diverse body areas and recognition of whole-body multiple diseases. We discuss the challenges that still persist in the multiple-lesion recognition tasks by critically assessing these efforts. Finally, we outline existing problems and potential future research areas, with the hope that this review will help researchers in developing future approaches that will drive additional advances.

Retinol and α-Tocopherol Levels in the Serum and Subcutaneous Adipose Tissue of Newly Diagnosed Basal Cell Carcinoma Patients

BACKGROUND

Nonmelanoma skin cancers are the most frequently occurring skin cancers. Vitamin A is involved in epithelial cell differentiation and may control skin tumor development. Vitamin E is a powerful lipophilic antioxidant that can quench and scavenge reactive oxygen species. However, there is little consistent evidence considering micronutrients and the development of basal cell carcinoma (BCC). Therefore, we aimed to investigate the possible difference between retinol and α-tocopherol in BCC patients and controls in Iranian population.

METHODS

This case-control study was conducted on adults with newly diagnosed BCC referred to Razi Hospital, Tehran, Iran in 2015. Serum and subcutaneous fat tissue retinol and α-tochopherol were measured by HPLC method.

RESULTS

Overall, serum retinol level was lower significantly in BCC patients (0.237±0.01 μg/ml) in comparison with control group (0.27±0.02 μg/ml, P-value: 0.038). However serum α-tocopherol level was not significantly different between BCC patients (4.41±0.33 μg/ml) and control subjects (4.06±0.35 μg/ml, P-value=0.18). Sub-cutaneous adipose tissue retinol was lower significantly in BCC patients (38.60±3.30 ng/mg) compared with control group (54.78±3.49 ng/mg, P-value=0.002). Furthermore, results revealed lower subcutaneous adipose tissue α-tocopherol in BCC patients (4.41±0.33 μg/ml) in comparison with control group (4.06±0.35 μg/ml, P-value=0.18).

CONCLUSION

Skin tissue concentration of retinol and α-tocopherol and serum retinol level was lower in BCC patients in comparison with control group but serum α-tocopherol was not different between groups.

Dermatological indications for the use of isotretinoin beyond acne

While the use of isotretinoin has revolutionized the treatment of acne vulgaris, isotretinoin is increasingly recognized as a useful therapeutic option for many other cutaneous conditions. We review the evidence underlying the use of isotretinoin for a variety of dermatological indications including hidradenitis suppurativa, sebaceous gland pathology, rosacea, scarring alopecia, cosmetic dermatology, and non-melanoma skin cancer prophylaxis amongst other uses, and thus consider alternative uses within dermatology practice. The studies found benefit of isotretinoin, however most trials lacked statistical power and in many cases the use was limited to case series. Isotretinoin, if used within the correct cohort with appropriate pretreatment counseling regarding side-effects, is a well-tolerated medication with potential as either an adjunctive treatment or a second-line agent in those recalcitrant cases unresponsive to first-line therapy.

Chemoprevention of Keratinocyte Carcinomas: An Updated Review

A well-established link between ultraviolet exposure and the carcinogenesis of keratinocyte carcinomas exists. Despite increased sun protection efforts, skin cancer remains the most common cancer in the USA. Numerous studies on the topic of chemoprevention investigate alternative topical, oral, and injectable agents to reduce skin cancer incidence in those at risk. Such agents include sunscreen, numerous vitamins and minerals, difluoromethylornithine, non-steroidal anti-inflammatory drugs, various peptides, field therapy, statins, and polyphenols. In this focused review, we discuss the risks and benefits of chemoprotective agents reported in clinical studies conducted in humans. We report several agents that may reduce skin cancer incidence in those at risk.

Is early detection of basal cell carcinoma worthwhile? Systematic review based on the WHO criteria for screening

The incidence of basal cell carcinoma (BCC) has risen three- to fourfold over the last 30 years and is expected to continue to increase with ageing of the population. Although BCC has a good prognosis, it causes significant morbidity and has an important impact on the public health budget due to direct treatment costs. Based on the existing evidence, a systematic evaluation of the World Health Organization criteria was performed to determine whether earlier detection of BCC could reduce morbidity and cost. BCC slowly increases in size, with a median increase in diameter of 0·5 mm over 10 weeks. There is an important delay in diagnosis ranging from 19 to 25 months. In several studies BCC size was the main determinant of treatment cost, surgical complexity, reconstruction technique and the specific surgical procedure performed, such as Mohs micrographic surgery or surgical excision. One study showed that size also seems to affect the cost per treatment for other nonsurgical options. The use of vismodegib, an inhibitor of the hedgehog pathway, is confined to locally advanced or metastatic BCC. Delays in diagnosis and appropriate treatment are the most important underlying causes in the occurrence of giant BCC and/or BCC with metastasis. Although the latter represent only a very small fraction of all BCCs, the majority of them are located in the facial region. The available data point to a slow increase in the size of BCCs over time. Size is one of the major determinants in choice of treatment and the associated cost, especially for facial BCC. Therefore we conclude that current data support early detection and adequate management of BCCs on the face.

Basal cell naevus syndrome: an update on genetics and treatment

Basal cell naevus syndrome is an autosomal dominant disorder that stems from mutations in multiple genes, most commonly patched 1 (PTCH1). The classic triad of symptoms consists of basal cell carcinomas, jaw keratocysts and cerebral calcifications, although there are many other systemic manifestations. Because of the broad range of symptoms and development of several types of tumours, early diagnosis and close monitoring are essential to preserve quality of life. Targeting treatment is often difficult because of tumour prevalence. Newer inhibitors of the hedgehog signalling pathway and proteins involved in proliferative growth have shown therapeutic promise. In addition, preventive medications are being devised. We propose a method for determining appropriate treatment for cutaneous tumours.

Basal cell carcinoma of the skin (part 2): diagnosis, prognosis and management

Basal cell carcinoma (BCC) is a heterogeneous malignant neoplasm with different biological and clinical behaviors, often slow growing and rarely metastatic and conveying an excellent prognosis. However, BCC is the most frequent skin cancer worldwide and can cause great morbidity, as most occur in high visible areas of the body, often relapse and may invade and destroy local tissues. This review aims to present a concise and updated overview of BCC histopathology and clinical presentation and progression. We also present a summary of currently available treatment options and some of the new promising agents.

Molecular cancer prevention: Current status and future directions

The heterogeneity and complexity of advanced cancers strongly support the rationale for an enhanced focus on molecular prevention as a priority strategy to reduce the burden of cancer. Molecular prevention encompasses traditional chemopreventive agents as well as vaccinations and therapeutic approaches to cancer-predisposing conditions. Despite challenges to the field, we now have refined insights into cancer etiology and early pathogenesis; successful risk assessment and new risk models; agents with broad preventive efficacy (eg, aspirin) in common chronic diseases, including cancer; and a successful track record of more than 10 agents approved by the US Food and Drug Administration for the treatment of precancerous lesions or cancer risk reduction. The development of molecular preventive agents does not differ significantly from the development of therapies for advanced cancers, yet it has unique challenges and special considerations given that it most often involves healthy or asymptomatic individuals. Agents, biomarkers, cohorts, overall design, and endpoints are key determinants of molecular preventive trials, as with therapeutic trials, although distinctions exist for each within the preventive setting. Progress in the development and evolution of molecular preventive agents has been steadier in some organ systems, such as breast and skin, than in others. In order for molecular prevention to be fully realized as an effective strategy, several challenges to the field must be addressed. Here, the authors provide a brief overview of the context for and special considerations of molecular prevention along with a discussion of the results from major randomized controlled trials.

Updated Physician's Guide to the Off-label Uses of Oral Isotretinoin

While oral isotretinoin is renowned for its ability to treat acne vulgaris, many of its off-label uses continue to go underappreciated. Since the last review on the unapproved indications of isotretinoin, relevant publications have surfaced with new recommendations. This article attempts to provide physicians with the latest information regarding successful and unsuccessful use of isotretinoin as an effective treatment for dermatological conditions, such as rosacea, psoriasis, pityriasis rubra pilaris, condyloma acuminatum, granuloma annulare, Darier's disease, systemic cutaneous lupus erythematosus, nonmelanoma skin cancer, and hidradenitis suppurativa. Variations in dosage regimens and isotretinoin viability as an alternative to other standard treatments are also discussed in relation to these conditions.