Chronic Sun Exposure Research Articles

Understanding and managing locally advanced basal cell carcinoma: insights into pathogenesis, therapeutic strategies, and the role of hedgehog pathway inhibitors.

Understanding and managing locally advanced basal cell carcinoma (BCC) is crucial given its substantial prevalence and potential for local tissue destruction. While BCC typically exhibits low metastatic potential, its high incidence underscores the need for enhanced therapeutic strategies. Locally advanced BCC presents unique challenges, often necessitating aggressive interventions to prevent disfigurement and functional impairment. The emergence of hedgehog pathway inhibitors (HHIs) offers promising therapeutic avenues by targeting aberrant hedgehog signaling, a key driver in BCC pathogenesis. Thus, elucidating the pathogenesis of locally advanced BCC and exploring the role of HHIs are critical endeavors in effectively managing this prevalent carcinoma. Epidemiologically, BCC primarily affects individuals with fair skin and chronic sun exposure, with an increasing incidence noted among younger age groups. Risk factors include UV radiation exposure, familial history of skin cancer, immunosuppression, and genetic syndromes such as basal cell nevus syndrome and xeroderma pigmentosum. Pathogenetically, BCC arises from cells in the skin's epidermis, with hedgehog pathway activation being a primary genetic driver, involving mutations in PTCH1 and SMO. Resistance to hedgehog inhibitors may occur due to genetic changes, complicating treatment strategies. BCC is characterized by low immunogenicity, which hinders immune response and contributes to treatment challenges. Enhanced understanding of the epidemiology, risk factors, and pathogenesis of locally advanced BCC, along with the development of targeted therapeutic approaches such as hedgehog pathway inhibitors, is essential for effectively managing this prevalent carcinoma and improving patient outcomes.

Cutis Rhomboidalis Nuchae and Solar Lentigo with Squamous and Basal Cell Carcinoma – A Quartet of Chronic Sun Exposure

Abstract Aging is of two types, namely extrinsic and intrinsic aging. Extrinsic aging or photoaging is caused mainly due to damage caused by solar radiation. We report the case of a elderly male who presented with large growth on the scalp and ulcer on the face. However, on clinical examination, almost all the changes of photoaging, namely solar lentigo, cutis rhomboidalis nuchae squamous, and basal cell carcinoma were present. This case highlights the importance of thorough clinical examination needed in the geriatric population for the early diagnosis and timely management of their ailments. This will not only prolong but also improve their quality of life.

Gene expression landscape of cutaneous squamous cell carcinoma progression.

Cutaneous squamous cell carcinomas (cSCCs) are the second most common human cancer and have been characterized by RNA sequencing (RNA-Seq); however, the transferability of findings from individual studies may be limited by small sample sizes and diverse analysis protocols. To define the transcriptome landscape at different stages in the progression of normal skin to cSCC via a meta-analysis of publicly available RNA-Seq samples. Whole-transcriptome data from 73 clinically normal skin samples, 46 actinic keratoses (AK) samples, 16 in situ SCC samples, 13 keratoacanthoma (KA) samples and 147 cSCC samples [including 30 samples from immunocompromised patients and 8 from individuals with recessive dystrophic epidermolysis bullosa (RDEB)] were uniformly processed to harmonize gene expression. Differential expression, fusion detection and cell-type deconvolution analyses were performed. Individual RNA-Seq studies of cSCC demonstrated study-specific clustering and varied widely in their differential gene expression detection. Following batch correction, we defined a consensus set of differentially expressed genes (DEGs), including those altered in the preinvasive stages of cSCC development, and used single-cell RNA-Seq data to demonstrate that DEGs are often - but not always - expressed by tumour-specific keratinocytes (TSKs). Analysis of the cellular composition of cSCC, KA and RDEB-cSCC identified an increase in differentiated keratinocytes in KA, while RDEB-cSCC contained the most TSKs. Compared with cSCC arising in immunocompetent individuals, cSCC samples from immunosuppressed patients demonstrated fewer memory B cells and CD8+ T cells. A comprehensive and unbiased search for fusion transcripts in cSCC and intermediate disease stages identified few candidates that recurred in >1% of all specimens, suggesting that most cSCC are not driven by oncogenic gene fusions. Finally, using Genotype-Tissue Expression (GTEx) data, we distilled a novel 300-gene signature of chronic sun exposure that affirms greater cumulative ultraviolet (UV) exposure in later stages of cSCC development. Our results define the gene expression landscape of cSCC progression, characterize cell subpopulation heterogeneity in cSCC subtypes that contribute to their distinct clinical phenotypes, demonstrate that gene fusions are not a common cause of cSCC and identify UV-responsive genes associated with cSCC development.

Clinical efficacy of intradermal type I collagen injections in treating skin photoaging in patients from high-altitude areas

BACKGROUND Photoaging, a result of chronic sun exposure, leads to skin damage and pigmentation changes. Traditional treatments may have limitations in high-altitude areas like Yunnan Province. Intradermal Col Ι injections stimulate collagen production, potentially improving skin quality. This study aims to assess the efficacy and safety of this treatment for photoaging. AIM To evaluate the efficacy and safety of intradermal type Ι collagen (Col Ι) injection for treating photoaging. METHODS This prospective, self-controlled study investigated the impact of intradermal injections of Col Ι on skin photodamage in 20 patients from the Yunnan Province. Total six treatment sessions were conducted every 4 wk ± 3 d. Before and after each treatment, facial skin characteristics were quantified using a VISIA skin detector. Skin thickness data were assessed using the ultrasound probes of the Dermalab skin detector. The Face-Q scale was used for subjective evaluation of the treatment effect by the patients. RESULTS The skin thickness of the right cheek consistently increased after each treatment session compared with baseline. The skin thickness of the left cheek significantly increased after the third through sixth treatment sessions compared with baseline. The skin thickness of the right zygomatic region increased after the second to sixth treatment sessions, whereas that of the left zygomatic region showed a significant increase after the fourth through sixth treatment sessions. The skin thickness of both temporal regions significantly increased after the fifth and sixth treatment sessions compared with baseline (P < 0.05). These findings were also supported by skin ultrasound images. The feature count for the red areas and wrinkle feature count decreased following the treatment (P < 0.05). VISIA assessments also revealed a decrease in the red areas after treatment. The Face-Q-Satisfaction with Facial Appearance Overall and Face-Q-Satisfaction with Skin scores significantly increased after each treatment session. The overall appearance of the patients improved after treatment. CONCLUSION Intradermal Col Ι injection improves photoaging, with higher patient satisfaction and fewer adverse reactions, and could be an effective treatment method for populations residing in high-altitude areas.

Extrafacial lentigo maligna: A progression model and enhanced diagnostic techniques using dermatoscopy and reflectance confocal microscopy.

Lentigo maligna (LM) is a subtype of lentiginous melanoma confined to the epidermis, which is associated with chronic sun exposure. Its clinical, dermatoscopic, and histopathological diagnosis can be challenging, particularly in the early and advanced stages, requiring appropriate clinicopathological correlation. This article reviews the clinical presentation, diagnosis through noninvasive methods (dermoscopy and confocal microscopy), and provides insights for diagnosis of extrafacial LM through the presentation of four representative clinical cases from different phases of a theoretical-practical progression model. Recognizing these lesions is crucial, as once they invade the dermis, they can behave like any other type of melanoma.

Clinical, dermoscopic and histopathological features of multiple cutaneous tumours ascribed to sun damage in a Chinese crested dog

AbstractThis case report describes the clinical, dermoscopic and histopathological findings of three different neoplastic lesions (angiokeratoma, squamous cell carcinoma and multiple melanocytomas) and non‐tumoral skin in a hairless Chinese crested dog following chronic sun exposure. The non‐tumoral skin was characterized by “sunburn cells”, collagen degeneration, dermal elastosis and fibrosis, described in most species as caused by UV light exposure. Cutaneous angiokeratomas have been rarely reported in the canine literature. In this particular case we consider a possible correlation with UV damage.

Melanocortin-1 Receptor Expression as a Marker of Progression in Melanoma.

Melanocortin-1 receptor (MC1R) plays a critical role in human pigmentation and DNA repair mechanisms. MC1R-targeting agents are being investigated in clinical trials in patients with melanoma, yet large studies investigating the rate and degree of MC1R expression in primary and metastatic human melanoma tissue are lacking. Using tissue microarrays containing three large cohorts of 225 cases of benign nevi, 189 with primary melanoma, and 271 with metastatic melanoma, we applied quantitative immunofluorescence and immunohistochemistry to comprehensively study MC1R protein expression. We show a stepwise elevation of MC1R expression in different stages of melanoma progression (nevi, primary, metastasis). Higher MC1R expression was seen in deeper (>1 mm) primary lesions and ulcerated lesions and was associated with shorter survival in primary and metastatic tumors. On multivariable analysis, Breslow thickness, male sex, and chronic sun exposure were independent predictors of worse overall survival in the primary melanoma cohort. Our data suggest that MC1R might be a valuable drug target in aggressive melanoma. Additional studies are warranted to determine its functional significance in melanoma progression and its utility as a predictive biomarker in patients receiving MC1R-directed therapies.

Actinic Reticuloid: A Literature Review of a Case

Actinic reticuloid is a chronic inflammatory skin condition that primarily affects elderly individuals and is associated with chronic sun exposure. It is characterized by the presence of papules, plaques, and fine lines that form a reticular pattern on sun-exposed areas, such as the face, neck, and extremities. Histologically, lichenification and dermal alterations are observed, suggesting a chronic response to sun exposure. Actinic reticuloid is often diagnosed clinically, but confirmation may require a skin biopsy. Managing this condition involves measures to protect the skin from the sun, such as the use of sunscreens and protective clothing. Topical and systemic treatments, such as corticosteroids and ultraviolet light therapy, may also be beneficial in some cases. Although the actinic reticuloid is not malignant, its chronic course and the aesthetic changes it produces can have a significant impact on patients' quality of life. Therefore, it is important for doctors to properly recognize and manage this condition in order to provide effective relief to affected patients.

A primary cutaneous carcinosarcoma of the retro auricular region, how to treat and literature review.

Carcinosarcomas are malignant biphasic tumours of epithelial and mesenchymal tissue. They are most often found in visceral organs, but also appear on the skin. Older age, male sex and chronic sun exposure are risk factors for its development. In this article we report a case and provide a review of literature regarding primary cutaneous carcinosarcoma (CCS) with special regard to its management. A manual electronic search of the PubMed Medline and Web of Science Core Collection databases was performed encompassing all included reports until 30th November 2022 to identify studies that reported primary CCS. CCS is a rare and aggressive tumour. Diagnosis requires histological examination and immunoreactivity of epithelial and mesenchymal components to specific markers. On its diagnosis, possibility of metastasis of a visceral carcinosarcoma should always be excluded. Surgical excision with clear margins, including the use of Mohs micrographic surgery (MMS), is the primary treatment for CCS. Reconstruction the excision defect should be performed. Regular follow-up for 5 to 10 years after initial treatment is advised. Awareness for CCS is necessary in the diagnostic evaluation of skin tumours. Further research is needed to better understand the underlying mechanisms of CCS and to establish optimal management strategies for this challenging malignancy. We recommend complete surgical excision using MMS as the treatment modality for this type of skin cancer. Dermatological follow-up for at least 5 years should be conducted to monitor for recurrence.

MicroRNA expression profiling of cutaneous squamous cell carcinomas and precursor lesions

AbstractBackgroundActinic keratoses (AK) are pre‐malignant skin lesions caused by chronic sun exposure. Progression from an AK to intraepidermal carcinoma (IEC) and a cutaneous squamous cell carcinoma (SCC) is well known but the rate of transformation to an invasive SCC is highly variable. Since no definitive biomarkers are available, treatment decisions are made ad hoc.ObjectivesTo fully characterise our AK to SCC progression series, we performed microRNA (miRNA) microarray expression profiling of normal and photodamaged skin, as well as AKs, IEC, and invasive SCCs.MethodsThe study recruited 27 patients who donated fresh biopsies of normal skin, photodamaged skin, AK, IEC, and SCC (n = 67 specimens). All miRbase (v.21) miRNAs were profiled to identify miRNAs related to SCC progression. miRNAs were validated using qRT‐PCR and in vitro phenotypic assays.ResultsThere were 234 robustly expressed miRNAs across the tissue collection, which resulted in 20 miRNA that were differentially expressed ((cor)p ≤ 0.05 and ≥ 10 fold) between normal skin and SCC. Hierarchical clustering all samples illustrated that AKs, IEC, and SCCs were largely indistinguishable, which confirms the premalignant status of an AK. A panel of miRNAs showed significant dysregulation between normal and photodamaged skin and AK. Importantly, we found miR‐34a‐5p and miR‐31‐5p had significant differential expression between AKs and IEC and IEC and SCC respectively. Phenotypic assays determined that the miR‐31 duplex had opposing effects on SCC cell lines which suggests that dysregulation of this duplex may be related to the dynamic control of progression of transformed keratinocytes.ConclusionsThis study confirmed the continuum of AK with IEC and SCC highlighting that miRNA expression plays a role in keratinocyte transformation. Development of our putative miRNA biomarker candidates is warranted to aid in clinical management of patients experiencing high AK load to determine the most appropriate treatment.

A chronic pro-inflammatory environment contributes to the physiopathology of actinic lentigines

Actinic lentigines (AL) or age spots, are skin hyperpigmented lesions associated with age and chronic sun exposure. To better understand the physiopathology of AL, we have characterized the inflammation response in AL of European and Japanese volunteers. Gene expression profile showed that in both populations, 10% of the modulated genes in AL versus adjacent non lesional skin (NL), i.e. 31 genes, are associated with inflammation/immune process. A pro-inflammatory environment in AL is strongly suggested by the activation of the arachidonic acid cascade and the plasmin pathway leading to prostaglandin production, along with the decrease of anti-inflammatory cytokines and the identification of inflammatory upstream regulators. Furthermore, in line with the over-expression of genes associated with the recruitment and activation of immune cells, immunostaining on skin sections revealed a significant infiltration of CD68+ macrophages and CD4+ T-cells in the dermis of AL. Strikingly, investigation of infiltrated macrophage subsets evidenced a significant increase of pro-inflammatory CD80+/CD68+ M1 macrophages in AL compared to NL. In conclusion, a chronic inflammation, sustained by pro-inflammatory mediators and infiltration of immune cells, particularly pro-inflammatory M1 macrophages, takes place in AL. This pro-inflammatory loop should be thus broken to normalize skin and improve the efficacy of age spot treatment.

2-Mercaptonicotinoyl glycine prevents UV-induced skin darkening and delayed tanning in healthy subjects: A randomized controlled clinical study.

Chronic nonextreme sun exposure induces two mechanisms of skin pigmentation, causing immediate darkening and delayed tanning. A new molecule, 2-mercaptonicotinoyl glycine (2-MNG), has been shown invitro to inhibit both immediate darkening and new melanin synthesis via covalent conjugation of the thiol group of 2-MNG to melanin precursors. To evaluate 2-MNG in preventing both mechanisms invivo. In a randomized, intra-individual and controlled study, 33 subjects with melanin-rich skin were exposed to UV daylight on designated areas on the back and treated with a cosmetic formula containing 0.5% or 1% 2-MNG alone or 0.5% 2-MNG in association with lipohydroxy acid (LHA, 0.3%) plus Mexoryl-SX (MSX, 1.5%). The respective vehicles were used as controls and 4-n-butyl-resorcinol (4-n-BR, 2.5%) as a positive reference. 2-MNG alone significantly reduced immediate darkening and inhibited new melanin production when compared with vehicle, with higher performance at 1% than at 0.5%. 2-MNG at 0.5% in association with LHA and MSX showed significantly higher performance than 2-MNG 0.5% alone. 2-MNG at 0.5% and 1% showed significantly better performance than 4-n-BR. 2-MNG inhibited both UV-induced skin pigmentation mechanisms invivo. The association of 2-MNG with LHA plus MSX showed the highest efficacy on melanin-rich skin with pigmentation induced by UV exposure.

Carcinoma squamous cell, are healthcare professionals prepared to identify it

Squamous Cell Carcinoma (SCC), is a type of cancer that originates in the squamous cells of the skin and has different stages according to the involved cellular layer. In the early stage, the process begins with chronic sun exposure, leading to DNA damage

Exposome and basal cell carcinoma: a multicenter case-control study.

While ultraviolet radiation (UVR) present in sunlight is recognized as the main etiological agent of skin cancer, the most frequent form of which is basal cell carcinoma (BCC), other exposome factors like pollution, diet, and lifestyle may also contribute. This study aimed to investigate the association of BCC and exposome-related factors in the Spanish population. BCC cases (n = 119) and controls (n = 127) with no history of skin cancer were recruited between April 2020 and August 2022 by 13 dermatologists throughout Spain in this prospective multicenter case-control study. The BCC group had a higher proportion of outdoor workers, more years of UVR exposure, and a greater consumption of drugs (statins, ASA, hydrochlorothiazide, ACE inhibitors and omeprazole), P < 0.05. Avoidance of sun exposure was the most used photoprotection measure in both groups. The use of hats or caps was higher in the BCC group (P = 0.01). The solar protection factor (SPF) used 15 years previously was higher in the control group (P = 0.04). The control group had a higher daily screen time (P < 0.001), and practiced more relaxation activities (P = 0.03). Higher linolenic acid intake and lower coffee consumption were the only dietary variables associated with BCC (P < 0.05). Statistical significance for all the aforementioned variables was maintained in the multivariate analysis (P < 0.05). The study found a significant association between BCC and multiple exposome-related factors in addition to chronic sunexposure in the Spanish population. Primary prevention strategies should target specific populations, such as outdoor workers, promoting sun-safe behaviors and stress-reducing activities, and also adequate skin photoprotection in patients on certain medications associated with increased BCC risk.

Epidemiological and clinical analysis of exposure-related factors in non-melanoma skin cancer: A retrospective cohort study

BackgroundThe incidence of non-melanoma skin cancers (NMSCs) increased over last decades, probably due to environmental concerns or to the increase of frail patients with age related comorbidities. Currently, the relationship of increasing global skin cancer rates with increased ultraviolet radiations (UVRs) resulting from stratospheric ozone depletion, global warming, and air pollution from fossil-fuel combustion. AimsWe conducted a retrospective epidemiological study including 546 NMSC patients managed at the Dermatology Unit of the Tor Vergata Hospital to highlight different trends of sun exposure or different comorbidities. MethodsDescriptive and inferential statistical analyses were performed to evidence differences between continous variable and Spearman rank test for dicotomical variables. Charlson Comorbidity Index was calculated to obtain the 10-years survival rate in order to identify the mean comorbidity burden of our patients. ResultsConsidering patients with comorbidities (73.81%), actinic keratoses (AKs) was the most frequent lesion. In patients with a history of previous melanoma, basal cell carcinoma (BCC) was predominant (ANOVA test, p < 0.05) with a statistically significant correlation (rho = 0.453; p < 0.01). Squamous cell carcinoma (SCC) showed a higher rate in arterial hypertension patients, followed by the chronic heart failure and hematologic neoplasms (60%, 29.7% and 32.1%, respectively) groups. Men were more affected than women, representing 61.54% of patients. Chronic sun exposure is directly correlated with SCC rho = 0.561; p < 0.01), whereas BCC correlated with a history of sunburns (rho = 0.312; p < 0.05). ConclusionsHistory of photo-exposition had an important role on NMSC development especially for work or recreational reasons. Sex, age, and presence of comorbidities influenced different NMSC types. BCC was more frequent in younger patients, associated with melanoma and sunburns. The presence of SCC is associated with older patients and the hypertension group. AKs were diagnosed predominantly in oldest men, with a chronic sun-exposure history, and hematologic neoplasms group.

Liquid biopsy for diagnostic and prognostic evaluation of melanoma.

Melanoma is the most aggressive form of skin cancer, and the majority of cases are associated with chronic or intermittent sun exposure. The incidence of melanoma has grown exponentially over the last 50years, especially in populations of fairer skin, at lower altitudes and in geriatric populations. The gold standard for diagnosis of melanoma is performing an excisional biopsy with full resection or an incisional tissue biopsy. However, due to their invasiveness, conventional biopsy techniques are not suitable for continuous disease monitoring. Utilization of liquid biopsy techniques represent substantial promise in early detection of melanoma. Through this procedure, tumor-specific components shed into circulation can be analyzed for not only diagnosis but also treatment selection and risk assessment. Additionally, liquid biopsy is significantly less invasive than tissue biopsy and offers a novel way to monitor the treatment response and disease relapse, predicting metastasis.

The Impact of Photoaging on Skin: A Systematic Review Analysis

Aging of the skin is a complex biological process. The process of skin aging can be divided into two categories namely intrinsic and extrinsic aging. Intrinsic skin aging or natural aging is caused by changes in skin elasticity that occur with age. This type of aging cannot be prevented. While extrinsic skin aging is caused by environmental factors such as exposure to solar radiation (photoaging). In this study, the type of research approach used is a type of qualitative research through a literature review. The type of data used is the type of secondary data. Secondary data is a type of data obtained from certain parties or media indirectly, meaning that certain parties become intermediaries where they obtain and record these data beforehand. The aging process of the skin is influenced by intrinsic and extrinsic factors. The extrinsic factor that most influences the aging process of the skin is chronic sun exposure which is called photoaging. Sunlight contains 96% UVA and has the most significant biological effect compared to UVB and UVC. Several factors that affect photodamaging are skin type, pigmentation, and acclimatization. Skin changes that occur in photoaging include the presence of vesicles in the epidermis, reduced Langerhans cells, and enlarged and pale epidermal cells; in the dermis, there is an elastic mass; pigment changes in the form of dotted (irregular pigmentation) and hyperpigmentation.

The Influence of the Exposome in the Cutaneous Squamous Cell Carcinoma, a Multicenter Case-Control Study.

The concept of exposome refers to the total of harmful and beneficial environmental exposures that can help predict the organism's biological responses over time. Ultraviolet radiation (UVR) from sun exposure has been recognized as the main etiological agent of skin cancer, and squamous cell carcinoma (SCC) is one most commonly associated with chronic exposure. However, in recent years, evidence suggests that lifestyle, environmental pollution, and contaminants in water and food can have an influence. To study the relationship between SCC and sun exposure, pollution, stress, and lifestyle in a Spanish cohort. A multicenter case-control study was carried out in which 13 dermatologists from different regions of Spain recruited cases and controls between April 2020 and August 2022. The group of cases were patients diagnosed with SCC and, as a control group, people who attended Dermatology consultations as companions with no history of skin cancer. A total of 62 patients with SCC and 126 controls were included (62.9% males, median age 76.46 (10.1) and 33.3%, median age 55.7 (15), respectively). The SCC group had experienced more outside work than the controls (75% vs. 22.4%, p < 0.001), less recreational exposure (sunbathing, p = 0.05, and outdoor sports, p = 0.01), and a lower annual income (p = 0.01), with an increase in tobacco exposure (p < 0.001), without differences in other carcinogens, such as ionizing radiation or chemical exposure. The control group had a higher daily screentime use (p < 0.001) and practiced more relaxation activities (p = 0.03). A higher linolenic acid intake and lower coffee consumption were the only dietary variables associated with SCC (p < 0.05). Some chronic medications (anxiolytics, antidepressants, beta-blockers, statins, hydrochlorothiazide, ACE inhibitors, metformin, and omeprazole) were also statistically associated with SCC. Statistical significance for all aforementioned variables was maintained in the multivariate analysis (p < 0.05). The study found a significant association between SCC and multiple exposome-related factors in addition to chronic sun exposure in the Spanish population. Primary prevention strategies should target specific populations, such as outdoor workers promoting sun-safe behaviors and stress-reducing activities, in addition to adequate skin photoprotection in patients under certain medications associated with SCC.

Skin ageing and topical rejuvenation strategies.

Skin ageing is a complex process involving the additive effects of skin's interaction with its external environment, predominantly chronic sun exposure, upon a background of time-dependent intrinsic ageing. Skin health and beauty is considered one of the principal factors perceived to represent overall 'health and wellbeing'; thus, the demand for skin rejuvenation strategies has rapidly increased, with a worldwide annual expenditure expected to grow from $US24.6 billion to around $US44.5 billion by 2030 (https://www.databridgemarketresearch.com/reports/global-facial-rejuvenation-market). Skin rejuvenation can be achieved in several ways, ranging from laser and device-based treatments to chemical peels and injectables; however, topical skin care regimes are a mainstay treatment for ageing skin and all patients seeking skin rejuvenation can benefit from this relatively low-risk intervention. While the most efficacious topical rejuvenation treatment is application of tretinoin (all-trans retinoic acid) - a prescription-only medicine considered to be the clinical 'gold standard' - a hybrid category of 'cosmeceutical' products at the midpoint of the spectrum of cosmetics and pharmaceutical has emerged. This article reviews the clinical manifestations of skin ageing and the available topical treatments for skin rejuvenation, including retinoids, peptides and antioxidants.

Increased Risk of Local Recurrence in Cutaneous Squamous Cell Carcinoma Arising in Sun-Exposed Skin: A Retrospective Cohort Study.

The incidence of cutaneous squamous cell carcinoma (cSCC) is increasing over the years. Risk factors for local recurrence and metastasis have been widely studied in highly sun-exposed areas of the body but less data exist about less sun-exposed ones. The main objective of this study is to compare the risk of local recurrence and metastases in patients with cSCC in highly sun-exposed areas compared to cSCC in less sun-exposed areas. A retrospective observational study was carried out, including 558 patients with histopathologically confirmed cSCC at the Reina Sofía University Hospital (HURS), Córdoba, during the period from 1 January 2017 to 31 December 2020. Demographic, clinical and anatomopathological data were collected. Local recurrence occurs more often in highly sun-exposed areas (15.8%) compared to less sun-exposed ones (7.4%) (p < 0.05). However, no differences in the rate of metastases in both groups were found. The presence of affected surgical margins and tumor thickness were identified as independent risk factors for cSCC in low sun-exposure areas. cSCC located in anatomical areas of high sun exposure presented a greater risk of developing local recurrence in our population, which could suggest that these tumors have worse prognosis than those that lie in areas that do not receive chronic sun exposure.