Diabetes and skin cancers: Risk factors, molecular mechanisms and impact on prognosis

Diabetic ulcer with cutaneous squamous cell carcinoma: A case report

BACKGROUND

Chronic skin ulcers are a risk factor for the development of skin tumors. In patients with diabetes, chronic refractory ulcers may also contribute to higher susceptibility to skin tumors. Timely surgical removal of chronic and nonhealing diabetic foot ulcers can effectively prevent progression to squamous cell carcinoma. Such cases may be misdiagnosed owing to currently insufficient clinical evidence. However, in cases of chronic ulcer wounds, it is crucial to enhance clinical awareness regarding their potential progression into malignant lesions.

CASE SUMMARY

An 84-year-old male patient with diabetes presented with a significantly ulcerated area on his foot. The ulcer had been present to varying degrees since 1996. Between 2012 and July 2019, even after receiving treatments such as herbal medicines or heat clearance and detoxification complete healing of the wound was not achieved. In July 2020, histopathological analysis confirmed a well-differentiated cutaneous squamous cell carcinoma. After the treatments, the ulcer wound healed slowly and did not expand.

CONCLUSION

Potentially malignant lesions in chronic ulcer wounds should be identified and treated in a timely manner to prevent their progression.

High-glucose impact on UVB responses in human epidermal keratinocytes: Insights on diabetic skin's resistance to photocarcinogenesis

Ultraviolet (UV) B-induced damage in human epidermal keratinocytes (HEKs) initiates photocarcinogenesis. However, how diabetes influences photocarcinogenesis is not well understood. To investigate the impact of high-glucose environments on responses to UVB, we cultured HEKs in normal-glucose (NG) or high-glucose (HG) conditions (G6 and G26), followed by UVB irradiation at 25 mJ/cm2 (G6UVB and G26UVB). We performed next-generation sequencing and analyzed HEKs' expression profiles bioinformatically to identify candidate genes and cellular responses involved. We found UVB induced consistent responses in both NG- and HG-cultivated HEKs, but it also triggered certain distinct processes and pathways specifically in the HG groups. The 459 differentially expressed (DE) genes in the HG groups revealed their roles in chromatin remodeling, nucleosome assembly, and interferon signaling activation. Moreover, the 29 DE genes identified in G26UVB/G6UVB comparison, including the potent tumor suppressor gene TFPI2, were considered key genes contributing to HEKs' altered response to UVB in HG environments. UVB irradiation induced significantly higher TFPI2 expression in HG-cultivated HEKs than their NG-cultivated counterpart. Finally, HG-cultivation significantly increased oxidative stress, cyclobutane pyrimidine dimer formation, and apoptosis, while reducing HEKs' viability after UVB irradiation. These changes under HG conditions probably mediate cell fate toward death and tumor regression. Overall, our findings provide evidence and associated molecular basis on how HG conditions reduce keratinocytes' photocarcinogenic potential following UVB exposure.

Analysis of the Stockholm Public Health Cohort: Exploring How Ultraviolet Radiation and Other Factors Associate with Skin Cancer

Objective

The primary aims of the study were to (1) explore the association of skin cancer and four ultraviolet radiation (UVR) indicators (sunbed use, healthcare data on diagnosed melanocytic nevi (MN) and actinic keratosis (AK), and latitude of birthplace), and (2) find factors other than UVR that could explain the increasing trend in incidence of skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and cutaneous malignant melanoma (CMM).

Methods

This population-based cohort study used self-reported questionnaire data from the Stockholm Public Health Cohort, encompassing 103 questions, merged with data from Swedish national registers. The study population included almost 35,000 Swedish-born people aged 30-66 years in 2014. Binomial logistic regression was employed for analysis. A forward stepwise regression was applied to select significant risk factors among all the factors included. We tentatively tested >30 variables separately for any relationship with each of the three skin cancers. A 5% level of significance was applied. Melanoma in situ and SCC in situ were excluded.

Results

The four UVR-related factors (sunbed use, being diagnosed with AK or MN, birthplace latitude) had a significant association with at least one of the three skin cancers that remained after adjustment including behavioural, social, hereditary, and medical factors. Sunbed use >10 times before age 30 years was related to all three skin cancers; SCC adjusted odds ratio (aOR) 1.66, 95% confidence interval (CI) 1.12-2.47, CMM (aOR 1.57, 95% CI 1.11-2.22), and the clearest dose-response association with BCC (aOR 1.74, 95% CI 1.46-2.06). None of the examined lifestyle factors, except physical activity, had any significant associations with UVR indicators or skin cancer.

Conclusion

We did not find any preventable explanatory cause other than UVR exposure for the increasing incidence of skin cancers. This result remained when adjusting for an array of possible confounders including behavioural, social, hereditary, and medical factors.

Macrophages, IL-10, and nitric oxide increase, induced by hyperglycemic conditions, impact the development of murine melanoma B16F10-Nex2

Epidemiological studies show a strong correlation between diabetes and the increased risk of developing different cancers, including melanoma. In the present study, we investigated the impact of a streptozotocin (STZ)-induced hyperglycemic environment on B16F10-Nex2 murine melanoma development. Hyperglycemic male C57Bl/6 mice showed increased subcutaneous tumor development, partially inhibited by metformin. Tumors showed increased infiltrating macrophages, and augmented IL-10 and nitric oxide (NO) concentrations. In vivo neutralization of IL-10, NO synthase inhibition, and depletion of macrophages reduced tumor development. STZ-treated TLR4 KO animals showed delayed tumor development; the transfer of hyperglycemic C57Bl/6 macrophages to TLR4 KO reversed this effect. Increased concentrations of IL-10 present in tumor homogenates of hyperglycemic mice induced a higher number of pre-angiogenic structures in vitro, and B16F10-Nex2 cells incubated with different glucose concentrations in vitro produced increased levels of IL-10. In summary, our findings show that a hyperglycemic environment stimulates murine melanoma B16F10-Nex2 primary tumor growth, and this effect is dependent on tumor cell stimulation, increased numbers of macrophages, and augmented IL-10 and NO concentrations. These findings show the involvement of tumor cells and other components of the tumor microenvironment in the development of subcutaneous melanoma under hyperglycemic conditions, defining novel targets for melanoma control in diabetic patients.

Role of Insulin Use and Social Determinants of Health on Non-melanoma Skin Cancer: Results From the Behavioral Risk Factor Surveillance System

BACKGROUND

Non-melanoma skin cancer (NMSC) is a frequent type of malignancy with a steadily increasing incidence rate worldwide. Although NMSC was shown to be associated with diabetes, no studies have addressed the extent to which insulin use influences the risk of NMSC in light of social determinants of health (SDOH). We conducted a quantitative study that examined the interplay between insulin use, SDOH, additional covariates, and NMSC among individuals with diabetes.

METHODS

We based our analysis on the 2020 Behavioral Risk Factor Surveillance System (BRFSS), a national survey conducted yearly in the US. We performed weighted chi-squared test, logistic regression, and survival analyses on 8685 eligible participants with diabetes enrolled in the BRFSS.

RESULTS

Kaplan Meier survival curves showed higher probability of NMSC event-free survival for participants with diabetes using insulin compared to participants with diabetes not using insulin (log-rank test P < .001). Significant associations were detected between insulin use and reduced odds of NMSC (OR .56; 95% CI: .38-.82), and decreased hazard (HR .36; 95% CI: .21-.62), along with indices of SDOH.

CONCLUSIONS

Our findings suggest that socioeconomic differences related to the healthcare system and behavioral patterns are linked to discrepancies in the use of insulin and the development of NMSC.

Exosomal Non-coding RNAs: A New Approach to Melanoma Diagnosis and Therapeutic Strategy

Malignant melanoma (MM) is a highly aggressive cancer with a poor prognosis. Currently, although a variety of therapies are available for treating melanoma, MM is still a serious threat to the patient's life due to numerous factors, such as the recurrence of tumors, the emergence of drug resistance, and the lack of effective therapeutic agents. Exosomes are biologically active lipid-bilayer extracellular vesicles secreted by diverse cell types that mediate intercellular signal communication. Studies found that exosomes are involved in cancer by carrying multiple bioactive molecules, including non-- coding RNAs (ncRNAs). The ncRNAs have been reported to play an important role in regulating proliferation, angiogenesis, immune regulation, invasion, metastasis, and treatment resistance of tumors. However, the functional role of exosomal ncRNAs in MM remains unknown. Therefore, this review summarizes the current state of melanoma diagnosis, treatment, and the application of exosomal ncRNAs in MM patients, which may provide new insights into the mechanisms involved in melanoma progression and serve as biomarkers for diagnosis and therapeutic targets.

Clinico-pathological Spectrum of Primary Skin Malignancies in an Indian Tertiary Care Hospital

Background

Skin malignancies are the most common form of malignant disease in the western world, predominantly affecting older age groups. The majority of skin cancers are basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and malignant melanoma, which account for more than 95% of total skin malignancies. However, in India, these constitute only 1-2% of all cancers. There is an increase in incidence in India over 10 years of period. There is scarcity of data on the clinico-pathological profile of these tumours from this geographical region.

Materials and Methods

This was a retrospective study conducted in a tertiary care teaching hospital in which archival records and histopathology sections of all patients of skin carcinomas diagnosed over a period of 5 years (January 2016 to December 2020) were analysed. The clinical parameters and histopathological features of the cases were analysed and correlated for any possible association.

Results

Out of the 230 skin malignancies studied, SCC constituted the most common type (n = 148), followed by BCC (n = 70) and malignant melanoma (n = 12). The tumour commonly presented in the 6th decade of life with slightly higher male preponderance (M: F =1.6:1). Sun-exposed areas were the most common sites, and the common presentations included non-healing ulcer, fungating/cauliflower/polypoidal growth, and hyperpigmented or nodular plaque. In SCC, previous history of diabetes and burns was noted in 10% and 3.4% of the patients, respectively.

Conclusion

SCC is likely the most common histological type of skin malignancies in India. The clinico-pathological profile of skin malignancies of patients depends on multiple factors, notably the skin colour and the geographical location.