Non-melanoma skin cancer: new and future synthetic drug treatments

The Role of Nicotinamide as Chemo-Preventive Agent in NMSCs: A Systematic Review and Meta-Analysis

BACKGROUND

Nicotinamide is the active form of vitamin B3 (niacin) obtained through endogenous synthesis, mainly through tryptophan metabolism and dietary supplements, fish, meats, grains, and dairy products. It participates in cellular energy metabolism and modulates multiple cellular survival and death pathways. Nicotinamide has been widely studied as a safe chemopreventive agent that reduces actinic keratosis (AKs) and non-melanoma skin cancers (NMSC).

METHODS

We used the Medline, EMBASE, PubMed, and Cochrane databases to search the concepts "nicotinamide", "chemoprevention", and "skin cancer" up to August 2023. Three independent authors screened titles and abstracts for intervention and study design before searching full texts for eligibility criteria. The primary outcome was the impact of oral nicotinamide on the incidence of NMSC in high-risk patients. We also conducted a systematic search to identify relevant epidemiological studies published evaluating dietary niacin intake and the risk of NMSC.

RESULTS

Two hundred and twenty-five studies were reviewed, and four met the inclusion criteria. There was no association between NAM consumption and risk for squamous cell carcinoma (SCC) (rate ratio (RR) 0.81, 95% CI 0.48-1.37; I2 = 0%), basal cell carcinoma (BCC) (RR 0.88, 95% CI 0.50-1.55; I2 = 63%), and NMSC (RR 0.82, 95% CI 0.61-1.12; I2 = 63%). Adverse events were rare and acceptable, allowing optimal compliance of patients to the treatment. We found only one article evaluating the association between niacin dietary intake and NMSC risk, supporting a potential beneficial role of niacin intake concerning SCC but not BCC or melanoma.

CONCLUSIONS

The present meta-analysis shows, by pooling immunocompetent and immunosuppressed patients, that there is insufficient evidence that oral nicotinamide therapy significantly reduces the number of keratinocyte cancers.

Advancing Cancer Research: Current Knowledge on Cutaneous Neoplasia

Skin cancers require a multidisciplinary approach. The updated guidelines introduce new insights into the management of these diseases. Melanoma (MM), the third most common skin cancer, a malignant melanocytic tumor, which is classified into four major histological subtypes, continues to have the potential to be a lethal disease. The mortality-incidence ratio is higher in Eastern European countries compared to Western European countries, which shows the need for better prevention and early detection in Eastern European countries. Basal cell carcinoma (BCC) and squamous cell carcinoma (cSCC) remain the top two skin cancers, and their incidence continues to grow. The gold standard in establishing the diagnosis and establishing the histopathological subtype in BCC and SCC is a skin biopsy. Sebaceous carcinoma (SeC) is an uncommon and potentially aggressive cutaneous malignancy showing sebaceous differentiation. It accounts for 0.7% of skin cancers and 3-6.7% of cancer-related deaths. Due to the rapid extension to the regional lymph nodes, SeC requires early treatment. The main treatment for sebaceous carcinoma is surgical treatment, including Mohs micrographic surgery, which has the advantage of complete margin evaluation and low recurrence rates. Primary cutaneous lymphomas (PCLs) are a heterogeneous group of lymphoproliferative diseases, with no evidence of extracutaneous determination at the moment of the diagnosis. PCLs have usually a very different evolution, prognosis, and treatment compared to the lymphomas that may secondarily involve the skin. The aim of our review is to summarize the important changes in the approach to treating melanoma, non-melanoma skin, cutaneous T and B cell lymphomas, and other types of skin cancers. For all skin cancers, optimal patient management requires a multidisciplinary approach including dermatology, medical oncology, and radiation oncology.

Orobol, 3'-hydroxy-genistein, suppresses the development and regrowth of cutaneous SCC

Chronic solar ultraviolet exposure is a major risk factor for cutaneous squamous cell carcinoma (cSCC), which is the second most common type of skin cancer. Our previous data showed that total protein and phosphorylation levels of T-LAK cell-originated protein kinase (TOPK) were enhanced in solar-simulated light (SSL)-induced skin carcinogenesis and overexpressed in actinic keratosis (AK) and cSCC human skin tissues compared to those in matched normal skin. Thus, targeting TOPK activity could be a helpful approach for treating cSCC. Our data showed that orobol directly binds to TOPK in an ATP-independent manner and inhibits TOPK kinase activity. Furthermore, orobol inhibited anchorage-independent colony formation by SCC12 cells in a dose-dependent manner. After discontinuing the treatment, patients commonly return to tumor-bearing conditions; therefore, therapy or intermittent dosing of drugs must be continued indefinitely. Thus, to examine the efficacy of orobol against the development and regrowth of cSCC, we established mouse models including prevention, and therapeutic models on the chronic SSL-irradiated SKH-1 hairless mice. Early treatment with orobol attenuates chronic SSL-induced cSCC development. Furthermore, orobol showed therapeutic efficacy after the formation of chronic SSL irradiation-induced tumor. In the mouse model with intermittent dosing of orobol, our data showed that re-application of orobol is effective for reducing tumor regrowth after discontinuation of treatment. Moreover, oncogenic protein levels were significantly attenuated by orobol treatment in the SSL-stimulated human skin. Thus, we suggest that orobol, as a promising TOPK inhibitor, could have an effective clinical approach to prevent and treat the development and regrowth of cSCC.

Changing trends in the disease burden of non-melanoma skin cancer globally from 1990 to 2019 and its predicted level in 25 years

Background

The disease burden of non-melanoma skin cancer (NMSC) has become a significant public health threat. We aimed to conduct a comprehensive analysis to mitigate the health hazards of NMSC.

Methods

This study had three objectives. First, we reported the NMSC-related disease burden globally and for different subgroups (sex, socio-demographic index (SDI), etiology, and countries) in 2019. Second, we examined the temporal trend of the disease burden from 1990 to 2019. Finally, we used the Bayesian age-period-cohort (BAPC) model integrated nested Laplacian approximation to predict the disease burden in the coming 25 years. The Norpred age-period-cohort (APC) model and the Autoregressive Integrated Moving Average (ARIMA) model were used for sensitivity analysis.

Results

The disease burden was significantly higher in males than in females in 2019. The results showed significant differences in disease burden in different SDI regions. The better the socio-economic development, the heavier the disease burden of NMSC. The number of new cases and the ASIR of basal cell carcinoma (BCC) were higher than that of squamous cell carcinoma (SCC) in 2019 globally. However, the number of DALYs and the age-standardized DALYs rate were the opposite. There were statistically significant differences among different countries. The age-standardized incidence rate (ASIR) of NMSC increased from 54.08/100,000 (95% uncertainty interval (UI): 46.97, 62.08) in 1990 to 79.10/100,000 (95% UI: 72.29, 86.63) in 2019, with an estimated annual percentage change (EAPC) of 1.78. Other indicators (the number of new cases, the number of deaths, the number of disability-adjusted life years (DALYs), the age-standardized mortality rate (ASMR), and the age-standardized DALYs rate) showed the same trend. Our predictions suggested that the number of new cases, deaths, and DALYs attributable to NMSC would increase by at least 1.5 times from 2020 to 2044.

Conclusions

The disease burden attributable to NMSC will continue to increase or remain stable at high levels. Therefore, relevant policies should be developed to manage NMSC, and measures should be taken to target risk factors and high-risk groups.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09940-3.

Wounding Therapies for Prevention of Photocarcinogenesis

The occurrence of non-melanoma skin cancer (NMSC) is closely linked with advanced age and ultraviolet-B (UVB) exposure. More specifically, the development of NMSC is linked to diminished insulin-like growth factor-1 (IGF-1) signaling from senescent dermal fibroblasts in geriatric skin. Consequently, keratinocyte IGF-1 receptor (IGF-1R) remains inactive, resulting in failure to induce appropriate protective responses including DNA repair and cell cycle checkpoint signaling. This allows UVB-induced DNA damage to proliferate unchecked, which increases the likelihood of malignant transformation. NMSC is estimated to occur in 3.3 million individuals annually. The rising incidence results in increased morbidity and significant healthcare costs, which necessitate identification of effective treatment modalities. In this review, we highlight the pathogenesis of NMSC and discuss the potential of novel preventative therapies. In particular, wounding therapies such as dermabrasion, microneedling, chemical peeling, and fractionated laser resurfacing have been shown to restore IGF-1/IGF-1R signaling in geriatric skin and suppress the propagation of UVB-damaged keratinocytes. This wounding response effectively rejuvenates geriatric skin and decreases the incidence of age-associated NMSC.

Non-Melanoma Skin Cancer in People Living With HIV: From Epidemiology to Clinical Management

Skin cancers represent the most common human tumors with a worldwide increasing incidence. They can be divided into melanoma and non-melanoma skin cancers (NMSCs). NMSCs include mainly squamous cell (SCC) and basal cell carcinoma (BCC) with the latest representing the 80% of the diagnosed NMSCs. The pathogenesis of NMSCs is clearly multifactorial. A growing body of literature underlies a crucial correlation between skin cancer, chronic inflammation and immunodeficiency. Intensity and duration of immunodeficiency plays an important role. In immunocompromised patients the incidence of more malignant forms or the development of multiple tumors seems to be higher than among immunocompetent patients. With regards to people living with HIV (PLWH), since the advent of combined antiretroviral therapy (cART), the incidence of non-AIDS-defining cancers (NADCs), such as NMSCs, have been increasing and now these neoplasms represent a leading cause of illness in this particular population. PLWH with NMSCs tend to be younger, to have a higher risk of local recurrence and to have an overall poorer outcome. NMSCs show an indolent clinical course if diagnosed and treated in an early stage. BCC rarely metastasizes, while SCC presents a 4% annual incidence of metastasis. Nevertheless, metastatic forms lead to poor patient outcome. NMSCs are often treated with full thickness treatments (surgical excision, Mohs micro-graphic surgery and radiotherapy) or superficial ablative techniques (such as cryotherapy, electrodesiccation and curettage). Advances in genetic landscape understanding of NMSCs have favored the establishment of novel therapeutic strategies. Concerning the therapeutic evaluation of PLWH, it’s mandatory to evaluate the risk of interactions between cART and other treatments, particularly antiblastic chemotherapy, targeted therapy and immunotherapy. Development of further treatment options for NMSCs in PLWH seems needed. We reviewed the literature after searching for clinical trials, case series, clinical cases and available databases in Embase and Pubmed. We review the incidence of NMSCs among PLWH, focusing our attention on any differences in clinicopathological features of BCC and SCC between PLWH and HIV negative persons, as well as on any differences in efficacy and safety of treatments and response to immunomodulators and finally on any differences in rates of metastatic disease and outcomes.

miR-18a expression in basal cell carcinoma and regulatory mechanism on autophagy through mTOR pathway

BACKGROUND

Basal cell carcinoma (BCC) is the most common form of skin carcinoma.

AIM

To investigate the function of key micro(mi)RNAs and to explore the potential molecular mechanisms involved in BCC.

METHODS

The microarray dataset GSE34535, which comprises seven BCC samples and seven control samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs (DE-miRNAs) were identified. We collected tissue samples from 20 patients with BCC and 20 healthy controls (HCs), to compare the miR-18a expression in their tissue samples. Expression of miR-18a in A431 and HaCaT cells was also assayed. Following this, we upregulated and downregulated miR-18a expression in A431 cells to examine the effects on cell proliferation, migration and apoptosis. To further investigate the relative mechanism, the proteins LC3, Beclin 1, Akt and mammalian target of rapamycin (mTOR) were examined by quantitative real-time PCR and Western blotting. For further verification, we examined the expression of LC3 in the 20 BCC and 20 HC tissue samples.

RESULTS

In total, 19 DE-miRNAs (13 upregulated and 6 downregulated) that were common to the BCC and HC groups were identified. Levels of miR-18a were about three-fold higher in BCC tissues and A431 cells compared with their respective control groups. In vitro, downregulation of miR-18a was shown to inhibit cell proliferation and activate autophagy via the Akt/mTOR signalling pathway, while upregulation of miR-18a promoted proliferation of these cells. LC3 was decreased in BCC compared with HC tissue samples.

CONCLUSIONS

Our data support an oncogenic role of miR-18a through a novel Akt/mTOR/Beclin 1/LC3 axis, and suggest that the antitumour effects of miR-18a inhibitor may make it suitable for BCC therapy.

Advanced cutaneous squamous cell carcinoma: how is it defined and what new therapeutic approaches are available?

PURPOSE OF REVIEW

Despite the overall excellent survival rates in patients with cutaneous squamous cell carcinoma (cSCC), advanced cutaneous SCCs are associated with high patient morbidity and mortality. Therefore, important unmet clinical needs persist: identifying high risk patients and choosing optimal treatment approaches.

RECENT FINDINGS

In recent years, a better understanding of the biology of cSCC and its clinical progression have led to improved staging systems and new promising treatments for advanced disease. Such treatments include PD1 inhibitors, such as cemiplimab, which was recently approved for the treatment of cutaneous SCC, and pembrolizumab whose efficacy in the treatment cSCC is still being investigated. Other treatments, such as epidermal growth factor receptor inhibitors have also been used in the treatment of cSCC with moderate success. Several clinical and histological risk factors are considered key in estimating the risk or recurrence or metastasis in cSCCs and, therefore, influence the appropriate treatment choice and patient monitoring.

SUMMARY

The present study reviews the current definition of advanced cSCC and discusses the new systemic approaches, including checkpoint inhibitors.

New perspectives in Merkel cell carcinoma

PURPOSE OF REVIEW

Merkel cell carcinoma (MCC), a rapidly progressing skin cancer, has poor prognosis. We reviewed the epidemiology, pathogenesis, diagnosis and treatment of MCC, with a focus on recent therapeutic advancements.

RECENT FINDINGS

Risk factors for MCC, such as old age, immunosuppression, polyomavirus infection and exposure to UV radiation have already been identified, but the underlying mechanisms leading to carcinogenesis still need clarification. On the basis of recent advances, immunotherapy - in particular, inhibition targeting the programmed cell death protein 1/programmed death-ligand 1 (PD1)/PDL1) immune checkpoint blockade - is currently being investigated in the treatment of metastatic MCC. Avelumab, an anti-PDL1 antibody, was the first drug to be approved internationally as second-line monotherapy for patients with advanced MCC, based on results from the JAVELIN Merkel 200 clinical trial. Avelumab has also recently been approved as first-line treatment for advanced MCC in Europe. Pembrolizumab (anti-PD1) in first-line and nivolumab (anti-PD1) in first-line and second-line treatments are two other checkpoint inhibitors that are under investigation, and showing promising results. New innovative therapies are also in development.

SUMMARY

New insights concerning advances in MCC diagnosis and treatment have been highlighted. Immunotherapy for metastatic MCC constitutes a recent breakthrough in an unmet medical need, but alternative therapies should continue to be investigated.

Characterisation of resistance mechanisms developed by basal cell carcinoma cells in response to repeated cycles of Photodynamic Therapy

Photodynamic Therapy (PDT) with methyl-aminolevulinate acid (MAL-PDT) is being used for the treatment of Basal cell carcinoma (BCC), but recurrences have been reported. In this work, we have evaluated resistance mechanisms to MAL-PDT developed by three BCC cell lines (ASZ, BSZ and CSZ), derived from mice on a ptch+/- background and with or without p53 expression, subjected to 10 cycles of PDT (10thG). The resistant populations showed mesenchymal-like structure and diminished proliferative capacity and size compared to the parental (P) cells. The resistance was dependent on the production of the endogenous photosensitiser protoporphyrin IX in the CSZ cell line and on its cellular localisation in ASZ and BSZ cells. Moreover, resistant cells expressing the p53 gene presented lower proliferation rate and increased expression levels of N-cadherin and Gsk3β (a component of the Wnt/β-catenin pathway) than P cells. In contrast, 10thG cells lacking the p53 gene showed lower levels of expression of Gsk3β in the cytoplasm and of E-cadherin and β-catenin in the membrane. In addition, resistant cells presented higher tumorigenic ability in immunosuppressed mice. Altogether, these results shed light on resistance mechanisms of BCC to PDT and may help to improve the use of this therapeutic approach.

Chimeric Monoclonal Antibody Cetuximab Targeting Epidermal Growth Factor-Receptor in Advanced Non-Melanoma Skin Cancer

BACKGROUND:

Non-melanoma skin cancer (NMSC) is the most common malignancy in humans. Targeted therapy with monoclonal antibody cetuximab is an option in case of advanced tumor or metastasis.

AIM:

We present and update of the use of cetuximab in NMSC searching PUBMED 2011-2017.

METHODS:

The monoclonal antibody cetuximab against epidermal growth factor receptor (EGFR) has been investigated for its use in NMSC during the years 2011 to 2017 by a PUBMED research using the following items: “Non-melanoma skin cancer AND cetuximab,” “cutaneous squamous cell carcinoma AND cetuximab,” and “basal cell carcinoma AND cetuximab”, and “cetuximab AND skin toxicity”. Available data were analyzed including case reports.

RESULTS:

Current evidence of cetuximab efficacy in NMSC was mainly obtained in cutaneous SCC and to a lesser extend in BCC. Response rates vary for neoadjuvant, adjuvant, mono- and combined therapy with cetuximab. Management of cutaneous toxicities is necessary. Guidelines are available.

CONCLUSIONS:

Cetuximab is an option for recurrent or advanced NMSC of the skin. It seems to be justified particularly in very high-risk tumors. There is a need for phase III trials.

Understanding the Molecular Genetics of Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common human cancer and represents a growing public health care problem. Several tumor suppressor genes and proto-oncogenes have been implicated in BCC pathogenesis, including the key components of the Hedgehog pathway, PTCH1 and SMO, the TP53 tumor suppressor, and members of the RAS proto-oncogene family. Aberrant activation of the Hedgehog pathway represents the molecular driver in basal cell carcinoma pathogenesis, with the majority of BCCs carrying somatic point mutations, mainly ultraviolet (UV)-induced, and/or copy-loss of heterozygosis in the PTCH1 gene. Recent advances in sequencing technology allowed genome-scale approaches to mutation discovery, identifying new genes and pathways potentially involved in BCC carcinogenesis. Mutational and functional analysis suggested PTPN14 and LATS1, both effectors of the Hippo–YAP pathway, and MYCN as new BCC-associated genes. In addition, emerging reports identified frequent non-coding mutations within the regulatory promoter sequences of the TERT and DPH3-OXNAD1 genes. Thus, it is clear that a more complex genetic network of cancer-associated genes than previously hypothesized is involved in BCC carcinogenesis, with a potential impact on the development of new molecular targeted therapies. This article reviews established knowledge and new hypotheses regarding the molecular genetics of BCC pathogenesis.

Updates on the Management of Non-Melanoma Skin Cancer (NMSC)

Non-melanoma skin cancers (NMSCs) are the most common malignancy worldwide, of which 99% are basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) of skin. NMSCs are generally considered a curable diseases, yet they currently pose an increasing global healthcare problem due to rising incidence. This has led to a shift in emphasis on prevention of NMSCs with development of various skin cancer prevention programs worldwide. This article aims to summarize the most recent changes and advances made in NMSC management with a focus on prevention, screening, diagnosis, and staging.