A cancer registry-based analysis on the non-white populations reveals a critical role of the female sex in early-onset melanoma

Phenotypic and genotypic risk factors for invasive melanoma by sex and body site

BACKGROUND

Cutaneous melanoma incidence varies consistently across body sites between men and women, but the underlying causes of the differences remain unclear. To date, no prospective studies have examined risk factors for melanoma separately for men and women according to body site.

METHODS

We compared the association between constitutional, genetic and environmental risk factors for invasive melanoma on different body sites separately for men and women in a population-based prospective cohort study of 17,774 men and 21,070 women aged between 40 and 69 years and residents of Queensland, Australia at baseline in 2011. Participants were followed until December 2021.We examined risk factors including hair colour, tanning ability, naevus density, and proxies for high cumulative sun exposure, all self-reported at baseline. We also examined polygenic risk score (PRS) derived from summary statistics from a melanoma genome-wide association study meta-analysis.

RESULTS

During a median 10.4 years of follow-up, 455 men and 331 women developed an incident invasive melanoma; the mean age at diagnosis was lower in women than in men (62.6 vs. 65.0, respectively). The most common body site was the trunk in men (45.1%), and the upper (36.8%) and lower limbs (27.4%) in women. High naevus density and proxy measures of high cumulative sun exposure were similarly associated with melanoma at all sites in men and women. In both sexes, high genetic risk was associated with melanoma on all body sites except the head and neck. We observed differences between men and women in the association between PRS and melanoma of the trunk (highest vs. lowest tertile of PRS: HR 2.78, 95% CI 1.64-4.69 for men; 1.55, 95% CI 0.63-3.80 for women), and non-significant but large differences for the lower limbs (HR 5.25, 95% CI 1.80-15.27 for men; 1.75, 95% CI 0.88-3.47 for women).

CONCLUSIONS

While there are a number of potential explanations for these findings, this raises the possibility that genetic factors other than those related to pigmentation and naevus phenotypes may play a role in the predilection for melanoma to arise on different sites between the sexes.

Does Sex Matter? Temporal Analyses of Melanoma Trends among Men and Women Suggest Etiologic Heterogeneity

The incidence and distribution of cutaneous melanoma differ between the sexes, but it is unclear whether these differences have been constant through time or across generations. We compared incidence trends by age, sex, and anatomic site by analyzing long-term melanoma data (1982-2018) in 3 populations residing at high-, moderate-, and low-ambient sun exposure: Queensland, Australia; United States White; and Scotland. We fit age-period-cohort models and compared trends in the male-to-female incidence rate ratio by site and sex. In men, melanoma incidence was always highest on the trunk; in women, incidence was historically highest on limbs, but there have been recent increases in truncal melanoma among females in all populations. The incidence rate ratio showed excess melanoma on the lower limb in females in most age groups in all populations. In contrast, there was a male excess of melanoma on the trunk (from about age 25 years) and head/neck (from about age 40 years), which increased with age. Birth cohort analyses identified turning points in incidence from high to low incidence among recent birth cohorts, which differed by population and site. Changing exposure to UVR is implicated, possibly superimposed upon innate differences between the sexes in site-specific susceptibility.

Distinctive lower incidence rates of cutaneous melanoma on the hips and lower extremities of men

BACKGROUND

Cutaneous melanomas (CMs) are more frequently found on the trunk in men, and on the hip and lower extremities (legs) in women. This discrepancy has been attributed to greater exposure to ultraviolet (UV) radiation of women's legs due to their dressing habits.

OBJECTIVES

To understand the sex difference in the bodily distribution of CMs, especially those on the legs.

METHODS

This was a cancer registry-based cohort study. CM incidences, relative tumour density and tumour mutational burdens (TMBs) were compared among different body sites in different sex and racial groups using the SEER (Surveillance, Epidemiology, and End Results) and TCGA SKCM (The Cancer Genome Atlas skin cutaneous melanoma) databases.

RESULTS

White men had lower rates and lower relative tumour density (RTD) of CMs on their legs compared with the rest of their body sites, or compared with White women. Men classified by SEER into racial groups other than White did not show such a trend. White women had comparable RTDs among different body sites. The ratios between the 'White' and the 'other' groups were used to evaluate the approximate effect of sun exposure at different body sites, which further validated a distinct protective effect of men's legs in melanoma. TMB on leg melanomas was lower than on other sites in both sexes.

CONCLUSIONS

The legs of both sexes in White patients show lower RTDs and lower levels of TMB, suggesting a weaker association with UV exposure. Furthermore, White men are especially protected against CM on their legs, suggesting an unknown intrinsic protective factor as compared with women.

Clustering trends of melanoma incidence and mortality: A worldwide assessment from 1995 to 2019

BACKGROUND

Melanoma is a skin cancer that has higher mortality among cutaneous malignant tumours. Tumour incidence in most world regions is rising. Here, we intend to highlight these trends in the world.

METHODS

We used the global burden of disease dataset to assess the incidence and mortality of melanoma from 1995 to 2019 in 204 countries/territories. To identify country/territory groups with similar trends of melanoma incidence and mortality, a model-based clustering with a mixture of multivariate t-distributions was used.

RESULTS

Australia and New Zealand had the largest incidence and mortality rates. Men in Egypt and women in Sri Lanka and Guam had the lowest incidence and mortality rates. The clustering analysis revealed 4 classes of incidence in both gender and 3 and 2 classes of mortality in male and female, respectively. All groups had a growing incidence rate in both gender, similar to the worldwide trend. In 10% of the countries/territories, central and Western Europe, the incidence increase rate was greater than in the countries/territories with the greatest incidence. The total mortality rate for men was steadily growing, although it was decreasing in Asian and African countries/territories. Overall, the mortality rate for women remained relatively steady over time.

CONCLUSION

Due to the increasing trend of melanoma in the world, primary and secondary prevention of this disease, especially in areas with higher incidence and mortality, is essential. Raising awareness about the disease is helpful in prevention and early detection of melanoma.

Skin Cancer in People of Color: A Systematic Review

BACKGROUND

People of African, Asian, Hispanic or Latino, Pacific Islander, and Native Indian descent are considered people of color by the Skin of Color Society (SOCS).

OBJECTIVES

In this study, we assess incidence, risk factors, clinical characteristics, histopathology, treatment, and survival for skin malignancies in people of color as defined by the SOCS, by systematically reviewing the literature.

METHODS

An electronic literature search of the PubMed, EMBASE, and MEDLINE databases was performed. Articles published from 1 January 1990 through 12 December 2020 were included in the search.

RESULTS

We identified 2666 publications potentially meeting the study criteria. Titles and abstracts of these studies were reviewed and 2353 were excluded. The full text of 313 articles were evaluated and 251 were included in this review.

CONCLUSION

Differences in incidence, patterns, treatment, and survival exist among people of color for cutaneous malignancies. Further research and initiatives are needed to account for and mitigate these differences.

Sex disparity in skin carcinogenesis and potential influence of sex hormones

Background

Sex or gender disparity in skin cancer has been documented for a long time at the population level. UV radiation (UVR) is a common environmental risk for all three major types of skin cancer: cutaneous melanoma (CM), basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). The underlying mechanism for sex disparity has been largely attributed to sex‐differentiated behaviour patterns related to UVR. Non‐UVR factors such as intrinsic physiological differences have been suggested but remain understudied.

Aims, Materials and Methods

This review summarizes and compares the known sex differences in three skin cancer types with regard to body site distribution and age influence.

Results

We found a similar age‐dependent sex difference pattern in CM and BCC. Specifically, CM and BCC tend to show higher incidence in young women and old men, with a switching age around menopause. The switching age suggests involvement of sex hormones, which has shown controversial influence on skin cancers at epidemiological level. Literatures regarding sex hormone receptors for oestrogen, androgen and progesterone are summarized for potential explanations at molecular level.

Discussion

Overall, more and more evidence suggests non‐UVR factors such as sex hormones play critical roles in skin cancer (especially CM and BCC), yet solid population and molecular evidence are required. Incidences of skin cancer are increasing which suggests limited effect for the current UVR‐avoidance prevention methods.

Conclusion

Fully understanding the causes of sex disparities in incidence is necessary for developing a comprehensive prevention strategy.

Comparative study of cutaneous melanoma and its associated issues between people of African decent and Caucasians

Cutaneous melanoma is uncommon in people of African descent unlike their Caucasian counterparts. This rarity of cutaneous melanoma in people of African descent makes studies in this group difficult. In the few studies that are available, several differences exist in the incidence, disease severity, course of the disease, treatment modalities and survival rates between these two groups. Observed difference in cutaneous melanoma between people of African descent and Caucasians include; a higher incidence and better prognosis in Caucasians, a low awareness of melanoma, no definite risk factors, presentation with advanced disease, poor melanoma specific survival in people of African descent. Other differences are a better UV-induced DNA damage recovery, acral as opposed to truncal melanoma, female preponderance and lack of preventive measures in people of African descent.

A Possible Link of Genetic Variations in ER/IGF1R Pathway and Risk of Melanoma

The mechanism of gender disparity in cutaneous melanoma incidence remains unclear. Steroid hormones including estrogens have long been implicated in the course of melanoma, but the conclusion is controversial. Estrogen receptors (ERs) and insulin-like growth factor 1 receptor (IGF1R) show extensive crosstalk in cancer development, but how the ER/IGF1R network impacts melanoma is currently unclear. Here we studied the melanoma associations of selected SNPs from the ER/IGF1R network. Part of the International Genes, Environment, and Melanoma (GEM) cohort was used as a discovery set, and the Gene Environment Association Studies Initiative (GENEVA) dataset served as a validation set. Based on the associations with other malignant disease conditions, thirteen single nucleotide polymorphism (SNP) variants in ESR1, ESR2, IGF1, and IGF1R were selected for candidate gene association analyses. The rs1520220 in IGF1 and rs2229765 in IGF1R variants were significantly associated with melanoma risk in the GEM dataset after Benjamini-Hochberg multiple comparison correction, although they were not validated in the GENEVA set. The discrepancy may be caused by the multiple melanoma characteristics in the GEM patients. Further analysis of gender disparity was carried out for IGF1 and IGF1R SNPs in the GEM dataset. The GG phenotype in IGF1 rs1520220 (recessive model) presented an increased risk of melanoma (OR = 8.11, 95% CI: 2.20, 52.5, p = 0.006) in men but a significant opposite effect in women (OR = 0.15, 95% CI: 0.018, 0.86, p = 0.045). The AA genotype in IGF1R rs2229765 (recessive model) showed a significant protective effect in men (OR = 0.24, 95% CI: 0.07, 0.64, p = 0.008) and no effect in women. Results from the current study are warranted for further validation.

Race-, Age-, and Anatomic Site-Specific Gender Differences in Cutaneous Melanoma Suggest Differential Mechanisms of Early- and Late-Onset Melanoma

In order to explore melanoma risk factors through gender-, age-, race-, and site-specific incidence rates, malignant melanoma cases from the Caucasian whites and non-whites were retrieved from the US SEER database. Age-standardized, age-, and site-specific tumor rates were calculated. All races and both genders showed positive annual average percentage changes (AAPCs) over the years, but AAPCs varied at different body sites, with men's trunk exhibiting the fastest increase. Non-whites were diagnosed at a significantly younger age than whites and showed a trend towards fewer gender differences in the age of diagnosis. However, non-whites and whites showed a similar pattern of age-specific gender differences in the incidence rate ratios. A consistent spiked difference (female vs. male, incidence rate ratio (IRR) >2) was observed at or near the age of 20⁻24 in all race groups and at all body sites. The highest female vs. male IRR was found in the hip and lower extremities, and the lowest IRR was found in the head and neck region in all races. These race-, gender-, and site-dependent differences suggest that age-associated cumulative sun exposure weighs significantly more in late-onset melanomas, while genetics and/or pathophysiological factors make important contributions to early-onset melanomas.

Human health in relation to exposure to solar ultraviolet radiation under changing stratospheric ozone and climate

The Montreal Protocol has limited increases in the UV-B (280-315 nm) radiation reaching the Earth's surface as a result of depletion of stratospheric ozone. Nevertheless, the incidence of skin cancers continues to increase in most light-skinned populations, probably due mainly to risky sun exposure behaviour. In locations with strong sun protection programs of long duration, incidence is now reducing in younger age groups. Changes in the epidemiology of UV-induced eye diseases are less clear, due to a lack of data. Exposure to UV radiation plays a role in the development of cataracts, pterygium and possibly age-related macular degeneration; these are major causes of visual impairment world-wide. Photodermatoses and phototoxic reactions to drugs are not uncommon; management of the latter includes recognition of the risks by the prescribing physician. Exposure to UV radiation has benefits for health through the production of vitamin D in the skin and modulation of immune function. The latter has benefits for skin diseases such as psoriasis and possibly for systemic autoimmune diseases such as multiple sclerosis. The health risks of sun exposure can be mitigated through appropriate sun protection, such as clothing with both good UV-blocking characteristics and adequate skin coverage, sunglasses, shade, and sunscreen. New sunscreen preparations provide protection against a broader spectrum of solar radiation, but it is not clear that this has benefits for health. Gaps in knowledge make it difficult to derive evidence-based sun protection advice that balances the risks and benefits of sun exposure.

Beyond the physician's perspective: A review of patient-reported outcomes in dermatologic surgery and cosmetic dermatology

Patient-reported outcome measures (PROMs) are utilized in health care to quantify the patient's perspective of a health condition or treatment on outcomes, such as health-related quality of life (HRQoL) and patient satisfaction. In dermatology, this is particularly relevant because the patient's perspective is critical in evaluating the outcome of cosmetic procedures as well as skin cancer treatment. We review seven validated PROMs that have been reported in the dermatologic surgery and cosmetic dermatology literature. For patients undergoing cosmetic procedures, the use of PROMs provides additional valuable outcome data beyond physician assessment. For patients with skin cancer, women experience a unique and often greater impact on HRQoL during treatment, which has been captured through PROMs. The recent development of multi-module instruments, such as the FACE-Q and FACE-Q Skin Cancer, have facilitated comprehensive assessments of treatment that impact multiple domains of HRQoL. The use of PROMs allows for dermatologists to reliably capture important disease- and treatment-related concerns, thus improving the patient experience.