Cutaneous squamous cell carcinoma in Norway 1963-2011: increasing incidence and stable mortality

Recent Changes in the Incidence and Characteristics of Cutaneous Squamous Cell Carcinomas in Finland from 2006 to 2020: A Retrospective Cohort Study

Registers recording only 1 tumour per patient do not enable assessment of the real burden of cutaneous squamous cell carcinoma. To investigate recent changes in the incidence and characteristics of tumours, a retrospective 15-year patient cohort study was performed in Finland. Histopathological diagnoses of cutaneous squamous cell carcinomas diagnosed between 2016 and 2020 were obtained from the pathology database and clinical data from patient medical records and combined with previously collected data for the years 2006-2015. Altogether 1,472 patients with 2,056 tumours were identified. The crude incidence increased from 19/100,000 persons in 2006 to 42 in 2020 (p < 0.001), increasing most in people aged over 80 years. The percentage of tumours located on the trunk increased from 5.3% during the first 5-year period, 2006-2010, to 9.0% in 2016-2020. Also, the location of tumours was significantly different between men and women, as men had more tumours on the scalp and ears, and women on the lower limbs. A slight change in the tumours from poorly to well differentiated and a decrease in the invasion depth were noted between 2006 and 2020. As the burden of tumours continues to increase, more attention should be paid to their prevention.

Age group-specific changes in keratinocyte cancer treatment rates in Australia, 2012-2021: a retrospective cohort study based on MBS claims data

OBJECTIVES

To examine recent changes in the numbers of Medicare-subsidised keratinocyte cancer excisions, particularly for younger people exposed to primary prevention campaigns since the early 1980s.

STUDY DESIGN

Retrospective cohort study; analysis of administrative data.

SETTING, PARTICIPANTS

Analysis of Medicare Benefits Schedule (MBS) claims data for procedures related to the diagnosis and treatment of keratinocyte cancer in Australia, 2012-2021.

MAIN OUTCOME MEASURES

Age-standardised rates for MBS-subsidised claims for first surgical squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) excisions, Mohs surgery, surgical excisions of benign lesions, skin biopsies, and cryotherapy or serial curettage of premalignant and malignant lesions, overall, and by sex, state/territory, and age group; average annual percentage change in rate for time intervals determined by joinpoint regression.

RESULTS

In men, the age-standardised rate of BCC/SCC excisions increased by 1.9% (95% confidence interval [CI], 1.4-2.4%) per year during 2012-2019 (from 2931 to 3371 per 100 000 men) and then declined by 3.8% (95% CI, 0.5-7.0%) per year during 2019-2021 (to 3152 per 100 000). In women, the age-standardised rate increased by 2.2% (95% CI, 1.7-2.8%) per year during 2012-2019 (from 1798 to 2093 per 100 000 women); the decline to 1967 excisions per 100 000 women in 2021 was not statistically significant. BCC/SCC excision rates declined for men under 55 years of age (by 1.0-3.4% per year) and women under 45 years of age (by 1.7-2.3% per year). Age-standardised biopsy rates increased during 2012-2021 in all age groups (by 2.8-6.9% per year).

CONCLUSIONS

Rates of MBS-subsidised treatment for keratinocyte cancers increased during 2012-2019, but BCC/SCC treatment rates declined among younger Australians, who have probably been exposed to less sunlight than earlier generations because of public health interventions and population-wide lifestyle changes related to technology use.

Lymphatic drainage patterns of malignant skin tumors in the head and neck region: a single-center retrospective study

BACKGROUND

This study aimed to clarify the relationship between primary site and lymphatic drainage pattern for malignant skin tumors in the head and neck region. Malignant melanoma and squamous cell carcinoma in the head and neck region are known to have poor prognosis because of lymph node metastasis. Nevertheless, numerous aspects of lymphatic drainage patterns remain elusive.

METHODS

We statistically analyzed data of 47 patients with malignant skin tumors in the head and neck region. Information was collected on the patients' clinical characteristics, primary tumor site, and lymphatic drainage patterns.

RESULTS

The parotid lymph nodes drained the greatest amount of lymph from skin tumors of the head and neck. Important lymphatic drainage pathways were the superficial cervical nodes for primary tumors in the buccal/nasal region, level IA and level IB nodes for primary tumors in the lip region, the occipital nodes, posterior auricular nodes, and level VA nodes in the parietal/occipital region, and the preauricular nodes in the auricular region.

CONCLUSION

These findings have considerable significance in terms of understanding lymphatic drainage patterns for malignant skin tumors in the head and neck and may be useful for clinical decision-making and when planning treatment. Further research and clinical applications are expected to contribute to an improved prognosis in patients with cutaneous head and neck malignancies.

An overview of cutaneous squamous cell carcinoma imaging diagnosis methods

Cutaneous squamous cell carcinoma, a type of non-melanoma skin cancer, is a form of keratinocyte carcinoma that stands as one of the most prevalent cancers, exhibiting a rising frequency. This review provides an overview of the latest literature on imaging methods for diagnosing squamous cell carcinoma (SCC) and actinic keratosis (AK). It discusses the diagnostic criteria, advantages, and disadvantages of various techniques such as dermatoscopy, skin ultrasound (US), in vivo and ex-vivo reflectance confocal microscopy (RCM), and line-field confocal optical coherence tomography (LC-OCT). These methods offer benefits including non-invasiveness, rapidity, comprehensive lesion imaging, and enhanced sensitivity, but face challenges like high costs and the need for specialized expertise. Despite obstacles, the use of these innovative techniques is expected to increase with ongoing technological advancements, improving diagnosis and treatment planning for keratinocyte carcinomas. Standardizing LC-OCT imaging algorithms for AK, Bowen's disease, and SCC remains an area for further research.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 1: Diagnostics and prevention-Update 2023

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in white populations, accounting for 20% of all cutaneous malignancies. Overall, cSCC mostly has very good prognosis after treatment, with 5-year cure rates greater than 90%. Despite the overall favourable prognosis and the proportionally rare deaths, cSCC is associated with a high total number of deaths due to its high incidence. A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), the European Society for Radiotherapy and Oncology (ESTRO), the European Union of Medical Specialists (UEMS), the European Academy of Dermatology and Venereology (EADV) and the European Organization of Research and Treatment of Cancer (EORTC), was formed to update recommendations on cSCC, based on current literature and expert consensus. Part 1 of the guidelines addresses the updates on classification, epidemiology, diagnosis, risk stratification, staging and prevention in immunocompetent as well as immunosuppressed patients.

Biomarkers found in the tumor interstitial fluid may help explain the differential behavior among keratinocyte carcinomas

Basal Cell Carcinomas (BCC) and cutaneous Squamous Cell Carcinomas (SCC) are the most frequent types of cancer, and both originate from the keratinocyte transformation, giving rise to the group of tumors called keratinocyte carcinomas (KC). The invasive behavior is different in each group of KC and may be influenced by their tumor microenvironment. The principal aim of the study is to characterize the protein profile of the Tumor Interstitial Fluid (TIF) of KC to evaluate changes in the microenvironment that could be associated with their different invasive and metastatic capabilities. We obtained TIF from 27 skin biopsies and conducted a label-free quantitative proteomic analysis comparing 7 BCCs, 16 SCCs, and 4 Normal Skins. A total of 2945 proteins were identified, 511 of them quantified in more than half of the samples of each tumoral type. The proteomic analysis revealed differentially expressed TIF-proteins that could explain the different metastatic behavior in both KC. In detail, the SCC samples disclosed an enrichment of proteins related to cytoskeleton, such as Stratafin and Ladinin1. Previous studies found their up-regulation positively correlated with tumor progression. Furthermore, the TIF of SCC samples was enriched with the cytokines S100A8/S100A9. These cytokines influence the metastatic output in other tumors through the activation of NF-kB signaling. According to this, we observed a significant increase in nuclear NF-kB subunit p65 in SCCs but not in BCCs. In addition, the TIF of both tumors was enriched with proteins involved in the immune response, highlighting the relevance of this process in the composition of the tumor environment. Thus, the comparison of the TIF composition of both KC provides the discovery of a new set of differential biomarkers. Among them, secreted cytokines such as S100A9 may help explain the higher aggressiveness of SCCs, while Cornulin is a specific biomarker for BCCs. Finally, the proteomic landscape of TIF provides key information on tumor growth and metastasis, which can contribute to the identification of clinically applicable biomarkers that may be used in the diagnosis of KC, as well as therapeutic targets.

Incidence, mortality and trends of cutaneous squamous cell carcinoma in Germany, the Netherlands, and Scotland

AIM OF THE STUDY

Cutaneous squamous cell carcinoma (cSCC) incidences are increasing but scarcely available separated. We analysed incidence rates of cSCC over three decades with an extrapolation to 2040.

METHODS

Cancer registries from the Netherlands, Scotland and two federal states of Germany (Saarland/Schleswig-Holstein) were sourced for separate cSCC incidence data. Incidence and mortality trends between 1989/90 and 2020 were assessed using Joinpoint regression models. Modified age-period-cohort models were applied to predict incidence rates up to 2044. Rates were age-standardised using the new European standard population (2013).

RESULTS

Age-standardised incidence rates (ASIR, per 100,000 persons per year) increased in all populations. The annual percent increase ranged between 2.4% and 5.7%. The highest increase occurred in the age groups ≥60 years, especially in men aged ≥80 years, with a three to 5-fold increase. Extrapolations up to 2044 showed an unrestrained increase in incidence rates in all countries investigated. Age-standardised mortality rates (ASMR) showed slight increases between 1.4 and 3.2% per year in Saarland and Schleswig-Holstein for both sexes and for men in Scotland. For the Netherlands, ASMRs remained stable for women but declined for men.

CONCLUSION

There was a continuous increase of cSCC incidence over three decades with no tendency for levelling-off, especially in the older populations as males ≥80 years. Extrapolations point to a further increasing number of cSCC up to 2044, especially among ≥60 years. This will have a significant impact on the current and future burden on dermatologic health care which will be faced with major challenges.

Stathmin 1 and p53 Expression in Cutaneous Squamous Cell Carcinoma and Precursor Lesions

ABSTRACT

Studies on the relationship between stathmin 1 (STMN1) and cutaneous squamous cell carcinoma (cSCC) are limited. We aimed to evaluate the relationship between clinicopathological factors and STMN1 and p53 expressions in cSCC and compare them with those in the precursor lesions of cSCC and normal tissue. A total of 195 patients, followed between January 2014 and December 2021, with diagnoses of primary cSCC (n = 129), in situ cSCC (n = 20), or actinic keratosis (n = 46), as well as 29 histopathologically normal tissue samples, were included in the study. Immunohistochemical staining for STMN1 and p53 was performed. In the cSCC group, STMN1 scores were higher in poorly differentiated ( P = 0.001) and ulcerated ( P < 0.001) tumors. A linear relationship between STMN1 score and tumor area, tumor thickness, and mitosis was found ( P = 0.001, P = 0.003, and P < 0.001, respectively). There was no statistically significant correlation between STMN1 and p53 scores. Our results support the previous view that STMN1 may be associated with some adverse clinicopathological and high-risk features of cSCC. To the best of our knowledge, this is the first and largest study to investigate STMN1 expression in cSCC, precancerous lesions of cSCC, and normal tissues.

Trends in keratinocyte skin cancer incidence, mortality and burden of disease in 33 countries between 1990 and 2017

BACKGROUND

Keratinocyte cancers (KCs) are the most common type of cancer in the White population worldwide, with associated high healthcare costs. Understanding the epidemiological trends for KCs, namely basal cell carcinomas (BCCs) and cutaneous squamous cell carcinomas (SCCs), is required to assess burden of disease, project future trends and identify strategies for addressing this pressing global health issue.

OBJECTIVES

To report trends in BCC and SCC incidence, and SCC mortality and disability-adjusted life-years (DALYs).

METHODS

An observational study of the Global Burden of Disease (GBD) database between 1990 and 2017 was performed. European Union countries and other selected high-income countries, including the UK and the USA, classified as having high-quality mortality data, were included. Annual age-standardized incidence rates (ASIRs), age-standardized death rates (ASDRs) and DALYs for each country were obtained from the GBD database. Trends were described using joinpoint regression analysis.

RESULTS

Overall, 33 countries were included. For both BCC and SCC in 2015-2017, the highest ASIRs were observed in the USA and Australia. Males had higher ASIRs than females at the end of the observation period in all countries for SCC, and in all countries but two for BCC. In contrast, the highest ASDRs for SCC were observed in Australia and Latvia for males, and in Romania and Croatia for females. The highest DALYs for SCC for both sexes were seen in Australia and Romania. Over the observation period, there were more countries demonstrating decreasing trends in mortality than in incidence, and disparities were observed between which countries had comparatively high mortality rates and which had high incidence rates. Overall reductions in SCC DALYs were observed in 24 of 33 countries for males, and 25 countries for females.

CONCLUSIONS

Over the past 27 years, although trends in SCC incidence have risen in most countries, there is evidence that mortality rates have been decreasing. Burden of disease as assessed using DALYs has decreased in the majority of countries. Future work will explore potential explanatory factors for the observed disparity in trends in SCC incidence and mortality.

Sex Disparity for Patients with Cutaneous Squamous Cell Carcinoma of the Head and Neck: A Systematic Review

The incidence of head and neck cutaneous squamous cell carcinoma (HNcSCC) is unevenly distributed between men and women. At present, the mechanism behind this disparity remains elusive. This study conducted a systematic review and meta-analysis of proportions to investigate the disparity between sexes for patients with HNcSCC. PubMed, Scopus, EMBASE, MEDLINE, Emcare and CINAHL were searched in November 2021 and June 2022 (N > 50, English, human), and studies which examined the association between sex and HNcSCC were included. Analysis was conducted using RStudio with data and forest plots displaying males as a proportion of total patients with HNcSCC. Two independent researchers performed study selection, data extraction, data analysis and risk of bias. Eighty-two studies (1948 to 2018) comprising approximately 186,000 participants (67% male, 33% female) from 29 countries were included. Significantly more males had HNcSCC overall (71%; CI: 67−74). Males were also significantly more affected by cSCC of the ear (92%; CI: 89−94), lip (74%; CI: 66−81), and eyelid (56%; CI: 51−62). This study found HNcSCC disproportionately affected males overall and across all subtypes. Improving our understanding of sex-specific mechanisms in HNcSCC will better inform our preventive, therapeutic and prognostic practices.

Advances in Cutaneous Squamous Cell Carcinoma Management

Simple Summary

Cutaneous squamous cell carcinoma (cSCC) is an increasingly prevalent and morbid cancer worldwide. Management of this cancer has changed significantly in the last decade through improved risk stratification and new therapies offering patients with locally advanced and metastatic disease more effective, less toxic, and more durable treatment options. Ongoing clinical trials are assessing new therapeutic options as well as optimizing existing regimens in efforts to better manage this cancer. The recent developments highlight the need for multidisciplinary care, especially for those with locally advanced and metastatic disease.

Abstract

cSCC is increasing in prevalence due to increased lifespans and improvements in survival for conditions that increase the risk of cSCC. The absolute mortality of cSCC exceeds melanoma in the United States and approaches that of melanoma worldwide. This review presents significant changes in the management of cSCC, focusing on improvements in risk stratification, new treatment options, optimization of existing treatments, and prevention strategies. One major breakthrough in cSCC treatment is the advent of immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1), which have ushered in a renaissance in the treatment of patients with locally advanced and metastatic disease. These agents have offered patients with advanced disease decreased therapeutic toxicity compared to traditional chemotherapy agents, a more durable response after discontinuation, and improved survival. cSCC is an active field of research, and this review will highlight some of the novel and more developed clinical trials that are likely to impact cSCC management in the near future.

NCCN Guidelines® Insights: Squamous Cell Skin Cancer, Version 1.2022

The NCCN Guidelines for Squamous Cell Skin Cancer provide recommendations for diagnostic workup, clinical stage, and treatment options for patients with cutaneous squamous cell carcinoma. The NCCN panel meets annually to discuss updates to the guidelines based on comments from panel members and the Institutional Review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new surgical recommendation terminology (peripheral and deep en face margin assessment), as well as recent updates on topical prophylaxis, immunotherapy for regional and metastatic disease, and radiation therapy.

Epidemiology of advanced cutaneous squamous cell carcinoma

Cutaneous invasive squamous cell carcinoma (cSCC) most commonly presents as a typically indolent tumour with five-year cure rates of >90%. Advanced cSCC has been defined as locally advanced or metastatic (locoregional or distant) cSCC. The epidemiological data on advanced cSCC are rare due to underreporting or exclusion of cSCC from national cancer registries. Although the frequency of local recurrence has been reported, there is no clear evidence on the incidence or mortality of locally advanced cSCCs, e.g. locally infiltrating or locally recurrent cSCCs that are not further amenable to curative surgery or radiotherapy. This gap of knowledge on the epidemiology of locally advanced cSCC, highlights the need for standardisation in defining and reporting both locally advanced and metastatic cSCC. Even though metastatic cSCCs are a small part of cSCCs (3%-5%), their aggressive characteristics contribute to significant morbidity, higher mortality and are those likely to require systemic treatments. Locally recurrent and metastatic cSCC may occur more frequently in high-risk cSCCs (up to 35%). The site of metastasis involves in the vast majority the regional lymph nodes, with the head and neck lymph nodes or parotid most commonly affected. Metastasis occurs mostly within 2-3 years of the primary cSCC diagnosis. The knowledge of the incidence and prognosis of advanced cSCC and the risk stratification of patients, who may progress to advanced cSCC, emerge as pressing research areas with important implications for cost-efficiency planning and optimisation of patient care.

A combination of preoperative or intraoperative MB-PDT and surgery in the treatment of giant cutaneous squamous cell carcinoma with infection

BACKGROUND

Giant cutaneous squamous cell carcinoma (cSCC) with infection is a major clinical issue, as the infection not only promotes the progress of tumor, but also effects the success of surgery. Traditional antibiotic treatment is not always sufficient to clear the infection, especially for cSCC infected with multidrug-resistant bacteria. Photodynamic therapy (PDT) has broad-spectral antibacterial activity and non-selective pressure, which makes it difficult to induce antibiotic resistance. Here, we aim to evaluate the safety and efficacy of PDT, along with photosensitizers MB (Methylene blue) - in the treatment of cSCC infected with multidrug-resistant bacteria.

METHODS

In our study, 6 patients with giant csCC accompanied infection were diagnosed by pathological examination and the depth of tumor tissues was examined by X-Ray or MRI. All patients' tumor wounds were firstly irradiated with MB-PDT (635 nm, 120 J/cm², 100 mW/cm²) using the red LED to control the infection. After the control of infection was confirmed by the culture of secretion, tumor underwent expanded resection. Multi-point pathological monitoring was performed during the operation to assure that there was no residual tumor tissue on the wound, and the primary or secondary repair was performed according to the condition of the wound. If the wound requires the tissue flaps transplation in secondary stage, the wound was irradiated again with intraoperative MB-PDT to remove the possible residual tumor cells, as well as to prevent wound infection. All patients were followed up for 0.8-3 years after flap transplation.

RESULTS

In 6 patients, the cSCC infection was completely controlled by MB-PDT, and the flap survival was 100%. There was no recurrence of cSCC in the follow-up of 1.6 years (range, 0.8-3 years) after the comminated treatment with MB-PDT and surgery.

CONCLUSIONS

Multi-drug resistant bacteria could efficiently be killed by MB-PDT, and the combination of surgery with MB-PDT is a safe and effective approach for treating giant cSCC with infection.

Temporal trends in the incidence rates of keratinocyte carcinomas from 1978 to 2018 in Tasmania, Australia: a population-based study

OBJECTIVES

We described incidence trends of keratinocyte carcinomas (KCs)-namely basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)-in the Australian state of Tasmania.

METHODS

We identified histologically confirmed KCs within the Tasmanian Cancer Registry (TCR) and conducted assessments to ensure data quality. Age-standardised incidence rates were calculated for first (1985-2018) and annual KCs (1978-2018). Average annual percentage changes were computed using Joinpoint regression models.

RESULTS

The TCR is a reliable source of KC data. A total of 83,536 people were registered with a KC between 1978 and 2018. Age-standardised incidence rates of first KCs increased on average by 3% per annum for BCCs and 4% per annum for SCCs, reaching 363/100,000 and 249/100,000 in 2018, respectively. Age-standardised incidence rates of annual KCs increased on average by 5% per annum for BCCs and 6% per annum for SCCs, up to 891/100,000 and 514/100,000 in 2018, respectively. This increase was steeper for females than males and highest during the late 1980s and early 1990s. A change in trend around 2014 suggested that incidence rates have started to decline.

CONCLUSION

While the incidence of KCs in Tasmania increased substantially over 41 years, rates have recently plateaued and started to decline. The findings may reflect changes in sun exposure behaviours due to awareness campaigns, but high incidence rates in 2018 indicate that KCs still pose a substantial burden to this population.

Cutaneous Malignancies of the Head and Neck

Cutaneous malignancies (CMs), or skin cancers, are the most common cancer worldwide, with a quarter million cases diagnosed annually in the United States alone. The best described risk factor for CM is ultraviolet radiation from sunlight, and therefore most of these cancers develop in sun-exposed skin, including the head and neck. Beginning with melanoma, immunotherapy has increasingly been used over the past decade for treatment of unresectable CM, and immune checkpoint inhibitors are now Food and Drug Administration-approved for first-line treatment of unresectable melanoma, Merkel cell carcinoma, and cutaneous squamous cell carcinoma, and second-line for basal cell carcinoma.

Association of Lifetime Indoor Tanning and Subsequent Risk of Cutaneous Squamous Cell Carcinoma

Importance

No study, to our knowledge, has prospectively investigated a dose-response association between lifetime indoor tanning and risk of cutaneous squamous cell carcinoma (SCC).

Objective

To investigate the dose-response association between lifetime indoor tanning and SCC risk, the association between duration of use and age at initiation with SCC risk, and the association between age at initiation and age at diagnosis.

Design, Setting, and Participants

This cohort study included data from women born from 1927 to 1963 from the Norwegian Women and Cancer study, established in 1991 with follow-up through December 31, 2015. Baseline questionnaires were issued to participants from 1991 to 2007, with follow-up questionnaires given every 5 to 7 years. Data analysis was performed from January 2, 2018, to March 2, 2019.

Exposures

Participants reported pigmentation factors. Sunburns, sunbathing vacations, and indoor tanning were reported for childhood, adolescence, and adulthood.

Main Outcomes and Measures

Information on all cancer diagnoses and dates of emigration or death were obtained through linkage to the Cancer Registry of Norway, using the unique personal identification number of Norwegian citizens.

Results

A total of 159 419 women (mean [SD] age at inclusion, 49.9 [8.3] years) were included in the study. During follow-up (mean [SD], 16.5 [6.4] years), 597 women were diagnosed with SCC. Risk of SCC increased with increasing cumulative number of indoor tanning sessions. The adjusted hazard ratio (HR) for highest use vs never use was 1.83 (95% CI, 1.38-2.42; P < .001 for trend). A significantly higher risk of SCC was found among women with 10 years or less of use (HR, 1.41; 95% CI, 1.08-1.85) and more than 10 years of use (HR, 1.43; 95% CI, 1.16-1.76) and among women with age at initiation of 30 years or older (HR, 1.36; 95% CI, 1.11-1.67) and younger than 30 years (HR, 1.51; 95% CI, 1.18-1.92) vs never users. No significant association was found between age at initiation and age at diagnosis (estimated regression coefficient, -0.09 [95% CI, -1.11 to 0.94] for age at initiation of ≥30 years and -0.02 [95% CI, -1.27 to 1.22] for <30 years vs never use).

Conclusion and Relevance

The findings provide supporting evidence that there is a dose-response association between indoor tanning and SCC risk among women. The association between cumulative exposure to indoor tanning and SCC risk was the same regardless of duration of use and age at initiation. These results support development of policies that regulate indoor tanning.

Incidence of Multiple vs First Cutaneous Squamous Cell Carcinoma on a Nationwide Scale and Estimation of Future Incidences of Cutaneous Squamous Cell Carcinoma

Importance

Until now, most studies on cutaneous squamous cell carcinoma (cSCC) incidence rates concerned only the first cSCC per patient. Given the increase in incidence rates and the frequent occurrence of subsequent cSCCs per patient, population-based data on the incidence rates of both first and multiple cSCCs are needed.

Objectives

To calculate annual age-standardized incidence rates for histopathologically confirmed first and multiple cSCCs per patient and to estimate future cSCC incidence rates up to 2027.

Design, Setting, and Participants

A nationwide population-based epidemiologic cohort study used cancer registry data on 145 618 patients with a first histopathologically confirmed cSCC diagnosed between January 1, 1989, and December 31, 2017, from the Netherlands Cancer Registry and all patients with multiple cSCCs diagnosed in 2017.

Main Outcomes and Measures

Age-standardized incidence rates for cSCC-standardized to the European Standard Population 2013 and United States Standard Population 2000-were calculated per sex, age group, body site, and disease stage. A regression model with positive slope was fitted to estimate cSCC incidence rates up to 2027.

Results

A total of 145 618 patients in the Dutch population (84 572 male patients [58.1%]; mean [SD] age, 74.5 [11.5] years) received a diagnosis of a first cSCC between 1989 and 2017. Based on incident data, European Standardized Rates (ESRs) increased substantially, with the highest increase found among female patients from 2002 to 2017, at 8.2% (95% CI, 7.6%-8.8%) per year. The ESRs for first cSCC per patient in 2017 were 107.6 per 100 000 person-years (PY) for male patients, an increase from 40.0 per 100 000 PY in 1989, and 68.7 per 100 000 PY for female patients, an increase from 13.9 per 100 000 PY in 1989, which corresponds with a US Standardized Rate of 71.4 per 100 000 PY in 2017 for men and 46.4 per 100 000 PY in 2017 for women. Considering multiple cSCCs per patient, ESRs increased by 58.4% for men (from 107.6 per 100 000 PY to 170.4 per 100 000 PY) and 34.8% for women (from 68.7 per 100 000 PY to 92.6 per 100 000 PY). Estimation of ESRs for the next decade show a further increase of 23.0% for male patients (ESR up to 132.4 per 100 000 PY [95% prediction interval, 125.8-139.0 per 100 000 PY]) and 29.4% for female patients (ESR up to 88.9 per 100 000 PY [95% prediction interval, 84.3-93.5 per 100 000 PY]).

Conclusions and Relevance

This nationwide epidemiologic cohort study suggests that incidence rates of cSCC keep increasing, especially among female patients, and that the occurrence of multiple cSCCs per patient significantly adds to the current and future burden on dermatologic health care. Revision of skin cancer policies are needed to halt this increasing trend.

MicroRNA-451a prevents cutaneous squamous cell carcinoma progression via the 3-phosphoinositide-dependent protein kinase-1-mediated PI3K/AKT signaling pathway

The role of microRNAs (miRNAs/miRs) in governing the progression of cutaneous squamous cell carcinoma (cSCC) has been the focus of recent studies. However, the functional role of miR-451a in cSCC growth remains poorly understood. Therefore, the present study aimed to determine the expression levels of miR-451a in cSCC cell lines and the involvement of miR-451a in cSCC progression. The results revealed that the expression levels of miR-451a were downregulated in cSCC tissues and cell lines, and that this subsequently upregulated 3-phosphoinositide-dependent protein kinase-1 (PDPK1) expression levels. PDPK1 was validated as a direct target of miR-451a in cSCC using bioinformatics software Starbase, dual-luciferase reporter gene assays and western blotting. Additionally, CCK-8, EdU and Transwell assays, as well as flow cytometry and Hoechst 3325 staining, were performed to assess the malignant aggressiveness of cSCC cells. Overexpression of miR-451a was demonstrated to impair the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), and promoted apoptosis in cSCC cells by interacting with PDPK1, possibly by direct targeting. Furthermore, the western blotting results indicated that miR-451a overexpression may block the PI3K/AKT signaling pathway by interacting with PDPK1. In conclusion, the findings of the present study suggested that miR-451a may prevent the proliferation, migration, invasion and EMT of cSCC cells through the PDPK1-mediated PI3K/AKT signaling pathway, which may offer potential therapeutic targets for the treatment of cSCC.

Association of Indoor Tanning Regulations With Health and Economic Outcomes in North America and Europe

Importance

UV radiation emissions from indoor tanning devices are carcinogenic. Regulatory actions may be associated with reduced exposure of UV radiation at a population level.

Objective

To estimate the long-term health and economic consequences of banning indoor tanning devices or prohibiting their use by minors only in North America and Europe compared with ongoing current levels of use.

Design, Setting, and Participants

This economic analysis modeled data for individuals 12 to 35 years old in North America and Europe, who commonly engage in indoor tanning. A Markov cohort model was used with outcomes projected during the cohort's remaining life-years. Models were populated by extracting data from high-quality systematic reviews and meta-analyses, epidemiologic reports, and cancer registrations.

Main Outcomes and Measures

Main outcomes were numbers of melanomas and deaths from melanoma, numbers of keratinocyte carcinomas, life-years, and health care and productivity costs. Extensive sensitivity analyses were performed to assess the stability of results.

Results

In an estimated population of 110 932 523 in the United States and Canada and 141 970 492 in Europe, for the next generation of youths and young adults during their remaining lifespans, regulatory actions that ban indoor tanning devices could be expected to gain 423 000 life-years, avert 240 000 melanomas (-8.2%), and avert 7.3 million keratinocyte carcinomas (-7.8%) in North America and gain 460 000 life-years, avert 204 000 melanomas (-4.9%), and avert 2.4 million keratinocyte carcinomas (-4.4%) in Europe compared with ongoing current levels of use. Economic cost savings of US $31.1 billion in North America and €21.1 billion (US $15.9 billion) in Europe could occur. Skin cancers averted and cost savings after prohibiting indoor tanning by minors may be associated with one-third of the corresponding benefits of a total ban.

Conclusions and Relevance

Banning indoor tanning may be associated with reduced skin cancer burden and health care costs. Corresponding gains from prohibiting indoor tanning by minors only may be smaller.

Solar UV Exposure and Mortality from Skin Tumors: An Update

Solar UV exposure is critical and complex in the etiology and prognosis of skin cancer, particularly cutaneous malignant melanoma. Sun exposure and one of its "derivatives," vitamin D, have been implicated in protection against mortality from melanoma. However, the relationships are inconsistent. At this time, it is not possible to make clear recommendations for or against sun exposure in relationship to melanoma prognosis. However, this relationship deserves continued exploration.

Complete Resolution of a Large, Locally-advanced Cutaneous Squamous Cell Carcinoma with the Immune-modulating PD-1 Inhibitor Pembrolizumab

Locally advanced cutaneous squamous cell carcinoma (cSCC) represents a challenge in treatment. Only very recently (February 2020) have guidelines been released regarding the management of unresectable, locally advanced cSCC. With the introduction of check point inhibitors during the last decade, anti-PD-1 antibodies represent a novel immunotherapeutic strategy in cancer. We present a case of an advanced cSCC not amenable to surgical resection, who experienced dramatic improvement following treatment with the programmed cell death protein 1 receptor (PD-1) inhibitor pembrolizumab as an immunotherapeutic strategy.

European interdisciplinary guideline on invasive squamous cell carcinoma of the skin: Part 1. epidemiology, diagnostics and prevention

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in the white populations, accounting for 20% of all cutaneous malignancies. Factors implicated in cSCC etiopathogenesis include ultraviolet radiation exposure and chronic photoaging, age, male sex, immunosuppression, smoking and genetic factors. A collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO) and the European Organisation of Research and Treatment of Cancer (EORTC) was formed to update recommendations on cSCC classification, diagnosis, risk stratification, staging and prevention, based on current literature, staging systems and expert consensus. Common cSCCs are typically indolent tumors, and most have a good prognosis with 5-year cure rates of greater than 90%, and a low rate of metastases (<4%). Further risk stratification into low-risk or high-risk common primary cSCC is recommended based on proposed high-risk factors. Advanced cSCC is classified as locally advanced (lacSCC), and metastatic (mcSCC) including locoregional metastatic or distant metastatic cSCC. Current systems used for staging include the American Joint Committee on Cancer (AJCC) 8th edition, the Union for International Cancer Control (UICC) 8th edition, and Brigham and Women's Hospital (BWH) system. Physical examination for all cSCCs should include total body skin examination and clinical palpation of lymph nodes, especially of the draining basins. Radiologic imaging such as ultrasound of the regional lymph nodes, magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography-computed tomography (PET-CT) scans are recommended for staging of high-risk cSCC. Sentinel lymph node biopsy is currently not recommended. Nicotinamide, oral retinoids, and topical 5-FU have been used for the chemoprevention of subsequent cSCCs in high-risk patients but are not routinely recommended. Education about sun protection measures including reducing sun exposure, use of protective clothing, regular use of sunscreens and avoidance of artificial tanning, is recommended.

Advanced Ulcerated Squamous Cell Carcinoma of the Hand with Locoregional Axillary Lymph Node Metastasis - Case Report and Literature Review

BACKGROUND:

Cutaneous squamous cell carcinoma (SCC) of the hand is the most common soft-tissue malignancy in this particular region. A literature survey suggested a higher rate of metastases in advanced SCC of the hand compared to head-and-neck cutaneous SCC.

CASE REPORT:

An 84-year-old man presented with an ulcerated firm tumour on the dorsum of his right hand. A diagnostic biopsy confirmed the diagnosis SCC. Imaging suggested an involvement of the tendons of digits 3 and 4. A diagnostic ultrasound suggested a loco-regional axillary lymph node metastasis. After discussion in the interdisciplinary tumour board, amputation of the affected digits followed by lymph node excision was recommended.

CONCLUSIONS:

Advanced SCC of the hand requires interdisciplinary management. Amputation is part of the surgical spectrum in advanced cases.

Metastasis of cutaneous squamous cell carcinoma in organ transplant recipients and the immunocompetent population: is there a difference? a systematic review and meta-analysis

BACKGROUND

Organ transplant recipients (OTR) have a higher risk of developing cutaneous squamous cell carcinoma (cSCC) compared to the immunocompetent population. Immunosuppression is often stated as a risk factor for metastasis. However, evidence for this is scarce.

OBJECTIVES

To investigate the cSCC metastasis risk in OTR and the immunocompetent population by systematically reviewing the literature.

METHODS

A systematic review of the literature was performed up to January 2018 using: Medline; Embase; Web of Science and ISI Science Citation Index. Studies assessing cSCC metastasis risk in ORT or immunocompetent cohorts were considered. A pooled risk estimate for metastasis was calculated for the immunocompetent population and OTR separately.

RESULTS

The pooled metastasis risk estimate for OTR was, respectively, 7.3% (95% CI 6.2-8.4) for cSCC on total body, and 11.0% (95% CI 7.7-14.8) for cSCC of the head neck area. For the immunocompetent population reported risk estimate analysis showed a pooled metastatic risk of 3.1% (95% CI 2.8-3.4) in total body cSCC and of 8.5% (95% CI 7.3-9.8) in cSCC of the head and neck area. Pooled risk estimate per single cSCC in OTR was 1.3% (95% CI 1.0-1.7) in total body cSCC and 4.0% (95% CI 2.7-5.5) in cSCC of the head and neck area. In the immunocompetent population, these pooled risk estimates were, respectively, 2.4% (95% CI 2.1-2.6) and 6.7% (95% CI 5.7-7.8).

CONCLUSIONS

Organ transplant recipients show a higher overall risk of cSCC metastasis compared to the immunocompetent population. Metastasis risks per single cSCC were substantially lower in both groups. However, due to heterogeneity and differences between studies, comparisons are difficult. Comprehensive follow-up studies with defined cohorts are necessary to adequately asses the risk for cSCC metastasis.

Antiproliferative 3-deoxysphingomyelin analogs: Design, synthesis, biological evaluation and molecular docking of pyrrolidine-based 3-deoxysphingomyelin analogs as anticancer agents

Sphingomyelins and glycerophospholipids are structurally related phospholipids. Nevertheless, glycerophospholipids analogs are known as antitumor agents while sphingomyelin analogs were reported as cytoprotective agents. Herein, we have addressed the development of 3-deoxysphingomyelin analogs as cytotoxic agents possessing modified sphingobases. Thus, pyrrolidine-based 3-deoxysphingomyelin analogs were synthesized and evaluated against a panel of cell lines representing four major types of cancers. Compounds 3d, 4d and 6d elicited better GI₅₀ values than the FDA approved drug miltefosine. Investigation of their impact on Akt phosphorylation as a possible mechanism for the antiproliferative activity of this class of compounds revealed that these compounds might elicit a concentration-dependent mechanism via inhibition of Akt phosphorylation at the lower concentration. Molecular docking predicted their binding modes to Akt to involve polar head binding to the Pleckstrin homology domain and hydrophobic tail extension into a hydrophobic pocket connecting the Pleckstrin homology domain and the kinase domain. As a whole, the described work suggests compounds 3d, 4d and 6d as promising pyrrolidine-based 3-deoxysphingomyelin analogs for development of novel cancer therapies.

All-cause mortality in patients with basal and squamous cell carcinoma: A systematic review and meta-analysis

BACKGROUND

There are varying reports of the association of basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (SCC) with mortality.

OBJECTIVE

To synthesize the available information on all-cause mortality after a diagnosis of BCC or SCC in the general population.

METHODS

We searched PubMed (1966-present), Web of Science (1898-present), and Embase (1947-present) and hand-searched to identify additional records. All English articles that reported all-cause mortality in patients with BCC or SCC were eligible. We excluded case reports, case series, and studies in subpopulations of patients. Random effects model meta-analyses were performed separately for BCC and SCC.

RESULTS

The searches yielded 6538 articles, and 156 were assessed in a full-text review. Twelve studies met the inclusion criteria, and 4 were included in the meta-analysis (encompassing 464,230 patients with BCC and with 175,849 SCC), yielding summary relative mortalities of 0.92 (95% confidence interval, 0.83-1.02) in BCC and 1.25 (95% confidence interval, 1.17-1.32) in SCC.

LIMITATIONS

Only a minority of studies controlled for comorbidities. There was significant heterogeneity in meta-analysis (χ2P < .001, I2 > 98%), but studies of SCC were qualitatively concordant: all showed statistically significant increased relative mortality.

CONCLUSIONS

We found that patients with SCC are at higher risk for death from any cause compared with the general population.

Long-term Change in the Risk of Skin Cancer After Organ Transplantation: A Population-Based Nationwide Cohort Study

Importance

The high risk of skin cancer after organ transplantation is a major clinical challenge and well documented, but reports on temporal trends in the risk of posttransplant cutaneous squamous cell carcinoma (SCC) are few and appear contradictory.

Objective

To study temporal trends for the risk of skin cancer, particularly SCC, after organ transplantation.

Design, Setting, and Participants

Population-based, nationwide, prospective cohort study of 8026 patients receiving a kidney, heart, lung, or liver transplant in Norway from 1968 through 2012 using patient data linked to a national cancer registry. The study was conducted in a large organ transplantation center that serves the entire Norwegian population of approximately 5.2 million.

Exposures

Receiving a solid organ transplant owing to late-stage organ failure, followed by long-term immunosuppressive treatment according to graft-specific treatment protocols.

Main Outcomes and Measures

Occurrence of first posttransplant SCC, melanoma, or Kaposi sarcoma of the skin. Risk of skin cancer was analyzed using standardized incidence ratios (SIRs) and, for SCC, multivariable Poisson regression analysis of SIR ratios, adjusting for 5-year time period of transplantation, different follow-up time, age, sex, and type of organ.

Results

The study cohort included 8026 organ transplant recipients, 5224 men (65.1%), with a mean age at transplantation of 48.5 years. Median follow-up time was 6.7 years per recipient; total follow-up time, 69 590 person-years. The overall SIRs for SCC, melanoma, and Kaposi sarcoma were 51.9 (95% CI, 48.4-55.5), 2.4 (95% CI, 1.9-3.0), and 54.9 (95% CI, 27.4-98.2), respectively. In those who underwent transplantation in the 1983-1987 period, the unadjusted SIR for SCC was 102.7 (95%, 85.8-122.1), declining to 21.6 (95% CI, 16.8-27.0) in those who underwent transplantation in the 2003-2007 period. Adjusting for different follow-up times and background population risks, as well as age, graft organ, and sex, a decline in the SIR for SCC was found, with SIR peaking in patients who underwent transplantation in the 1983-1987 period and later declining to less than half in patients who underwent transplantation in the 1998-2002, 2003-2007, and 2008-2012 periods, with the relative SIRs being 0.42 (95% CI, 0.32-0.55), 0.31 (95% CI, 0.22-0.42), and 0.44 (95% CI, 0.30-0.66), respectively.

Conclusions and Relevance

The risk of SCC after organ transplantation has declined significantly since the mid-1980s in Norway. Less aggressive and more individualized immunosuppressive treatment and close clinical follow-up may explain the decline. Still, the risk of SCC in organ transplant recipients remains much higher than in the general population and should be of continuous concern for dermatologists, transplant physicians, and patients.

Early Life UV and Risk of Basal and Squamous Cell Carcinoma in New South Wales, Australia

Sun exposure is the main cause of squamous (SCC) and basal cell carcinoma (BCC) although pattern and amount differ by cancer type, and sun sensitivity is the major host risk factor. Our study investigated risk factors and residential ambient UV in a population-based sample of Australian 45 and Up Study participants: 916 BCC cases, 433 SCC cases, 1224 controls. Unconditional logistic regression models adjusting for key covariates demonstrated 60% increased BCC risk and two-fold increased SCC risk with sun sensitivity, and three- and four-fold increased risk, respectively, with solar keratoses. BCC but not SCC risk increased with higher early-life residential UV in all participants (odds ratio (OR) = 1.54; 95% CI 1.22-1.96 for intermediate; OR = 1.31; 95% CI 1.03-1.68 for high UV at birthplace) and similarly in Australian-born participants (P-values < 0.05). Risk of SCC but not BCC increased with long-term cumulative sun exposure assessed by self-reported outdoor work (OR 1.74, 95% CI 1.21-2.49). In conclusion, sun sensitivity is important for both cancers, early-life UV but not cumulative UV appears to increase BCC risk, the former an apparently novel finding, and SCC risk appears only to be related to long-term cumulative sun exposure.

Incidence trends and survival of skin melanoma and squamous cell carcinoma in Cluj County, Romania

The aim of this study was to determine the incidence trends of cutaneous melanoma (CM) and squamous cell carcinoma (SCC) in Cluj County, from 1998 to 2011, and the 5-year net survival between 2006 and 2010. Data on all cases of CM and SCC between 1998 and 2011 were obtained from Cluj Cancer Registry. Incidence rates were age standardized by the direct method Age Standardized Incidence Rate (ASIR), using the world standard population. Trends and annual percentage change (APC) of incidence rates were calculated by joinpoint regression analysis. The Pohar-Perme estimator was used to examine the 5-year net survival of cases diagnosed during 2006-2010 and followed up until December 2015. A total of 580 cases of CM and 397 cases of SCC were reported. During 1998-2011, the ASIR of CM increased significantly by 7.8% APC in male patients and by 7.42% APC in female patients, and the ASIR for SCC increased by 9.40% APC in male patients. In female patients, the incidence of SCC increased by 12.65% APC during 2002-2011. The 5-year net survival during 2006-2010 was 0.64 in men and 0.75 in women for CM and 0.86 and 1.00, respectively, for SCC. Survival rates showed an improving trend during 2006-2010, and were generally lower in men. Survival from both entities decreased with age and was lower in rural areas and in advanced stages in both sexes. This study reveals a rising incidence of cutaneous cancers in concordance with international trends. These data support the important role of primary and secondary prevention of skin cancers, focusing not only on melanoma, due to its lower survival, but also on SCC, in order to reduce their burden.

Aromatic hydrocarbons and risk of skin cancer by anatomical site in 25 000 male offshore petroleum workers

BACKGROUND

We prospectively examined skin cancer risk according to occupational exposure to aromatic hydrocarbons with adjustment for ultraviolet radiation exposure, in a cohort of 24 917 male offshore petroleum workers.

METHODS

Hazard ratios (HRs) and 95% confidence intervals were estimated with Cox regression adapted to a stratified case-cohort design.

RESULTS

During 13.5 years of follow-up, 112 cutaneous melanomas (CMs) and 70 non-melanoma skin cancers were identified. Increased risks of CM and of squamous cell carcinoma on the forearm and hand were seen among those ever exposed to crude oil or benzene. For skin cancers of the forearm and hand combined, cumulative and duration metrics of benzene exposure showed P_trends of 0.031 and 0.003, respectively.

CONCLUSIONS

Our results support an association between exposure to crude oil or benzene and skin cancer risk on hands and forearms among offshore petroleum workers. Dermal uptake of polycyclic aromatic hydrocarbons or benzene may explain this association.

Squamous cell carcinoma in the Afro-Caribbean community: an 11-year retrospective study

BACKGROUND

Squamous cell carcinoma (SCC) is considered the most frequent skin cancer in Black people. Its incidence is not known in the Afro-Caribbean population.

OBJECTIVE

To assess the incidence of SCC in Guadeloupe, the largest island of the Lesser Antilles (405 000 inhabitants, mostly Black people of African and European descent). The second objective was to characterize clinical and histological patterns of SCC occurring in the Afro-Caribbean community.

METHODS

This retrospective study was conducted over an 11-year period (2000-2010). Data regarding 723 histological confirmed cases of SCC identified using the three Guadeloupean pathology laboratories' computerized databases were retrieved from the records of 551 patients. Private practice dermatologists and general practitioners were contacted to obtain any missing data.

RESULTS

The annual age-adjusted incidence of SCC was 15 per 100.000 residents in Guadeloupe. In the Afro-Caribbean community, SCC had a greater size (i.e. 2.8 ± 2.8 cm vs. 1.5 ± 1.0 cm, P < 0.001), was more often located on the anogenital area (i.e. 48/79-60.8% vs. 14/320-4.4%, P < 0.001) in association with an underlying dermatosis due to HPV infection (15/71-21.1% vs. 3/366, 0.8%, P < 0.001) and led more frequently to metastasis (13/84-15.5% vs. 10/366-2.7%, P < 0.001) and/or fatal evolution (11/83-13.3% vs. 7/365-1.9%, P < 0.001).

CONCLUSIONS

The results of this original study, which first estimated the incidence of SCC in West Indies, suggest that anogenital examination should be routinely performed in skin cancer screening of Afro-Caribbean people to detect the presence of SCC at an early stage.

IMPLICATION FOR PRACTICE

Squamous cell carcinoma is the most frequent skin cancer in Black people. Its incidence is not known in the Afro-Caribbean population. In Guadeloupe, the largest island of the Lesser Antilles, the annual age-adjusted incidence of SCC was estimated to be 15.0 per 100 000 residents, 95% CI:[13.8; 16.2]. In the Guadeloupean Afro-Caribbean community, SCC seems to more frequently occur in the anogenital area, due to HPV infection. These results support to include a routine genital urinary examination in the skin cancer screening of people of Afro-Caribbean descent.

Epidemiology of Keratinocyte Carcinoma

Purpose of the review

To provide a synopsis of recent research advances in the epidemiology of keratinocyte carcinoma (KC), with a focus on indoor tanning and known risk factors for other forms of cancer such as cigarette smoking and alcohol drinking.

Recent findings

The evidence is strong enough to infer that use of UVR-emitting indoor tanning devices cause KC. Epidemiologic studies of cigarette smoking, alcohol drinking, and menopausal hormone therapy all show some suggestion for increased risk of KC but the evidence is not yet strong enough to determine if there is a true etiologic role. Body mass index is clearly inversely associated with KC risk but this is more likely to be due to lower UVR exposure in overweight and obese individuals than it is due to a true etiologic role.

Summary

The epidemic of KC continues unabated, and the causal role of indoor tanning is contributing to this unfavorable trend in KC incidence rates. Advances in understanding the etiology of KC should not divert attention away from the fact that the primary public health strategy to prevent KC is known: minimize population exposure to UVR from the sun and from UVR-emitting indoor tanning devices, particularly among those with sun-sensitive phenotypes.

Cutaneous squamous cell carcinoma: an epidemiological review

Cutaneous squamous cell carcinoma (SCC) is a common cancer in white populations and its disease burden is often substantially underestimated. SCC occurs more often in men than women and increases dramatically with age; those affected often develop multiple primaries over time, which increases the burden. The main external cause is solar ultraviolet radiation (UVR), with immunosuppression being the other established risk factor, shown by the high SCC rates in organ transplant recipients. Sunbed use and certain genetic disorders and medical conditions are also associated with SCC, while associations with human papillomavirus infection and high bodyweight are not established. The presence of actinic keratoses (AKs) on sun-damaged skin is one of the strongest predictors of SCC in unaffected people and a very small proportion of AKs are SCC precursors, although the true rate of malignant transformation of AKs is unknown. The mainstay of SCC prevention is protection of the skin from undue sun exposure by use of clothing cover and sunscreen during summer or in sunny places. Educational, behavioural and multicomponent interventions directed at individuals ranging from parents of newborns, to school children and adolescents, to outdoor workers, have repeatedly been shown to be effective in improving sun-protective behaviours. Health policies can facilitate SCC prevention by setting standards for relevant behaviours to reduce UVR exposure, for example, by legislated restriction of the tanning industry. Skin cancer prevention initiatives are generally highly cost-effective and public investment should be encouraged to control the growing public health problems caused by SCC.

The role of immunosuppression in squamous cell carcinomas arising in seborrheic keratosis

BACKGROUND

Seborrheic keratoses (SK) are common skin neoplasms considered to be benign. Reports of associated squamous cell carcinoma arising within seborrheic keratosis (SCC-SK) have been described.

OBJECTIVE

To describe the histopathologic characteristics of SCC-SK and identify predisposing factors in formation of these rare lesions.

METHODS

There were 162 cases of SCC-SK in a span of a decade (2003-2014). All of the histopathologic specimens and medical records were reviewed. Data from these patients were compared to a control group with seborrheic keratosis who were matched by age, sex, and location of lesion from the same time period (n = 162).

RESULTS

SCC-SK has the classic histopathologic features of SK, such as hyperkeratosis, parakeratosis, papillomatosis, and pseudohorn cysts. The areas of squamous cell carcinoma were characterized by areas of squamous dysplasia (100%), hypogranulosis (79.6%), squamous eddies (79.6%), solar elastosis (80.9%), and brown pigmentation (59.9%). Patients with a history of immunosuppression had an increased risk for developing SCC-SK (19% vs 3%; P < .01), particularly when inhibition was transplant-associated (10% vs 0%; P < .01).

LIMITATIONS

This was a single center, retrospective study.

CONCLUSION

SCC-SK occurs more often in elderly men with a history of immunosuppression associated with organ transplants.

Stimulation of dendritic cells by DAMPs in ALA-PDT treated SCC tumor cells

Photodynamic therapy (PDT) not only kills tumor cells directly but also rapidly recruits and activates immune cells favoring the development of antitumor adaptive immunity. It is believed that Topical 5-aminolevulinic acid mediated photodynamic therapy (ALA-PDT) can induce anti-tumor immune responses through dangerous signals damage-associated molecular patterns (DAMPs). In this study, we investigated the effect of ALA-PDT induced DAMPs on immune cells. We focused on the stimulation of dendritic cells by major DAMPs, enhanced the expression of calreticulin (CRT), heat shock proteins 70 (HSP70), and high mobility group box 1 (HMGB1), either individually or in combination. We evaluated in vitro and in vivo expressions of DAMPs induced by ALA-PDT using immunohistochemistry, western blot, and ELISA in a squamous cell carcinoma (SCC) mouse model. The role of DAMPs in the maturation of DCs potentiated by ALA-PDT-treated tumor cells was detected by FACS and ELISA. Our results showed that ALA-PDT enhanced the expression of CRT, HSP70, and HMGB1. These induced DAMPs played an important part in activating DCs by PDT-treated tumor cells, including phenotypic maturation (increase of surface expression of MHC-II, CD80, and CD86) and functional maturation (enhanced capability to secrete IFN-γ and IL-12). Furthermore, injecting ALA-PDT-treated tumor cells into naïve mice resulted in complete protection against cancer cells of the same origin. Our findings indicate that ALA-PDT can increase DAMPs and enhance tumor immunogenicity, providing a promising strategy for inducing a systemic anticancer immune response.

Occupation and relative risk of cutaneous squamous cell carcinoma (cSCC): A 45-year follow-up study in 4 Nordic countries

BACKGROUND

The age-adjusted incidence of cutaneous squamous cell carcinoma (cSCC) in the Nordic countries has increased during the last 60 years, and the identification of occupational variation in the relative risk of cSCC may have preventive implications.

OBJECTIVE

We sought to describe variation in the relative risk of cSCC between occupational categories in Finland, Iceland, Norway, and Sweden.

METHODS

This is a historical prospective cohort study based on record linkages between census data for 12.9 million people and cancer registry data from 1961 to 2005. Standardized incidence ratios for cSCC were estimated for 53 occupational categories with the cSCC incidence rates for the national population of each country used as reference.

RESULTS

During follow-up, 87,619 incident cases of cSCC were reported to the national cancer registries. In all countries combined, significant increased standardized incidence ratios were observed among seamen, military personnel, public safety workers, technical workers, teachers, transport workers, physicians, dentists, nurses, other health workers, religious workers, clerical workers, administrators, and sale agents (standardized incidence ratios between 1.08 and 1.77).

LIMITATIONS

Information on occupation was based on 1 point in time only.

CONCLUSION

The occupational variation of the relative risk of cSCC might be associated with socioeconomic factors, and to some extent to occupational exposures.

Keratinocyte Carcinoma as a Marker of a High Cancer-Risk Phenotype

Keratinocyte carcinoma (KC) (also referred to as nonmelanoma skin cancer) is by far the most common form of human cancer. A personal history of KC is well established to be associated with increased risk of recurrent KC and malignant melanoma, a less common yet more fatal form of skin cancer. More surprising is that a substantial body of epidemiologic evidence now indicates that a personal history of KC is significantly associated with an overall elevated risk of noncutaneous malignancies. This association is not limited to one or a few types of cancer but applies across many different types of malignancy. This association has been consistently observed in prospective studies across genders for both major histologic types of KC, basal cell carcinoma and squamous cell carcinoma. The risk of other cancers has been even stronger in those with younger compared with older age of onset of KC. A robust body of evidence lends support to the notion that KC may be a marker of a high cancer-risk phenotype. The underlying mechanisms for this association remain to be elucidated, but the cross-cutting nature of this association across numerous malignancies suggests that research to uncover these mechanisms is a promising line of inquiry that could potentially yield valuable insight into human carcinogenesis.