Sex differences in the association of cutaneous melanoma incidence rates and geographic ultraviolet light exposure

Gender differences, UV exposure and risk of lentigo maligna in a nationwide healthcare population cohort study

BACKGROUND

Our understanding of the relationship between ultraviolet (UV) radiation exposure and lentigo maligna (LM) has been largely derived from epidemiologic/clinical studies based on invasive melanoma. Recent studies have shown gender differences in melanocytic tumours incidence.

OBJECTIVE

To examine the association of UV light with LM by gender remains unclear.

METHODS

Two prospective cohort study [Nurses' Health Study (1980-2012)] and [Health Professionals Follow-up Study (1986-2010)] were analysed. All participants with LM or MIS, non-LM type were included in analysis. UV index at birth, age 15, and age 30 were calculated by gender. Lifetime UV flux was calculated. Hazard ratios (HRs) were calculated.

RESULTS

A total of 110 485 women from NHS and 41 015 men from HPFS were examined. A total of 281 LM and 776 melanoma in situ (MIS), non-LM cases were reported. Risk of LM increased with increasing UV flux exposure in multivariate-adjusted models for men (P for trend = 0.04), but not for women (P for trend = 0.91).

CONCLUSIONS

UV flux may be associated with LM in men but not in women.

The World of Melanoma: Epidemiologic, Genetic, and Anatomic Differences of Melanoma Across the Globe

PURPOSE OF REVIEW

As cancer remains an increasing problem in industrial countries, the incidence of melanoma has risen rapidly in many populations during the last decades and still continues to rise. Current strategies aiming to control the disease have largely focused on improving the understanding of the interplay of causal factors for this cancer.

RECENT FINDINGS

Cutaneous melanoma shows clear differences in incidence, mortality, genomic profile, and anatomic presentation, depending on the country of residence, ethnicity, and socioeconomic status. Known risk factors are multiple atypical nevi, positive family and/or personal history, immune suppressive diseases or treatments, and fair skin phenotype. Besides new adjuvant therapeutic options, changed attitude toward leisure and sun exposure, primary prevention, and early detection are major contributors to disease control. Melanoma is a disease of multifactorial causality and heterogeneous presentation. Its subtypes differ in origin, anatomical site, role of UV radiation, and mutational profile. Better understanding of these differences may improve prevention strategies and therapeutic developments.

Ultraviolet radiation-mediated development of cutaneous melanoma: An update

Ultraviolet (UV) light is absorbed by nucleic acids, proteins or other endogenous chromophores, such as porphyrins, flavins and melanin, triggering biological processes in skin cells. Both UV-induced mutations in melanocytes and changes in the immune microenvironment are understood to play a role in the development of cutaneous melanoma. The degree of UV-induced stress and the protection against this stress are influenced by both intracellular and intercellular molecular interactions. The present review summarizes the known major molecular biological changes induced by UV light in the skin that play a role in melanoma initiation and promotion. Nevertheless, cutaneous melanoma is not a homogenous disease, and the interaction of variable environmental exposure and different genetic susceptibility and other host factors lead to the formation of melanomas with different biological behavior and clinical characteristics. This review highlights the challenges in the understanding of how UV radiation contributes to the formation of cutaneous melanoma, and reviews the new results of photobiology and their link to tumor genetics and tumor immunology with potential implications on melanoma prevention and therapeutic strategies. The information presented here is expected to add clarity to ongoing research efforts in this field to aid the development of novel strategies to prevent and treat melanoma.

Childhood experiences of parenting and cancer risk at older ages: findings from the English Longitudinal Study of Ageing (ELSA)

Objectives

Despite the importance of childhood experiences for adult health and psychosocial factors for cancer development, parenting, a key childhood psychosocial exposure, has yet to be studied in relation to cancer risk at older ages. We examined whether childhood experiences of poor-quality parenting are associated with an increased risk of cancer at older ages.

Methods

We used a sample of 4471 community dwellers aged ≥ 55 years in 2007. Poor-quality parenting was defined as low levels of parental care and high levels of parental overprotection.

Results

Overall poorer experiences of parenting, decreasing parental care and increasing parental overprotection were associated with increased risk of incident all-site and skin cancer in men, but not in women. Increasing paternal overprotection was also associated with increased risk of incident colorectal cancer in men. Overall poorer experiences of parenting and increasing paternal overprotection were associated with increased risk of prevalent all-site and colorectal cancer in women. Adjustment for covariates explained a small part of these associations.

Conclusions

Older adults who reported childhood experiences of poorer quality parenting appear to have an increased risk of cancer. These findings improve our understanding of the role of psychosocial factors in cancer over the life course.

Electronic supplementary material

The online version of this article (10.1007/s00038-018-1117-3) contains supplementary material, which is available to authorized users.

Cutaneous Melanoma-A Long Road from Experimental Models to Clinical Outcome: A Review

Cutaneous melanoma is a complex disorder characterized by an elevated degree of heterogeneity, features that place it among the most aggressive types of cancer. Although significant progress was recorded in both the understanding of melanoma biology and genetics, and in therapeutic approaches, this malignancy still represents a major problem worldwide due to its high incidence and the lack of a curative treatment for advanced stages. This review offers a survey of the most recent information available regarding the melanoma epidemiology, etiology, and genetic profile. Also discussed was the topic of cutaneous melanoma murine models outlining the role of these models in understanding the molecular pathways involved in melanoma initiation, progression, and metastasis.

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

PURPOSE

Most melanoma studies have been performed in the white population who exhibits the highest incidence rate due to their skin sensitivity to UV radiation. Previous publications have shown that young women (approximately under the menopausal age) exhibit higher incidence rates than men of the same age, and the causes are mostly attributed to their sun behavior or indoor tanning. In our recent publications, we suggested that higher risk in younger women was due to pathophysiological factors, such as hormonal impact, and thus this higher risk in young women should be shared across ethnicities regardless of their skin color or UV behavior.

METHODS

A total of 13,208 non-white melanoma patients from SEER and 15,226 from WHO CI5-Plus were extracted for analysis. Age-specific incidence rates, female-to-male incidence rate ratios, and p values were calculated.

RESULTS

As observed in the white population, younger women and older men showed higher melanoma incidence rates than their peers of the other gender in all ethnic groups. The highest female-to-male incidence rate ratios were observed in the pubescent and reproductive ages. Previously this gender discrepancy in the white population was attributed to the preference of skin tanning in young females. There is no evidence to show that darker-skinned young females adopt a similar tanning preference. Thus the age-dependent gender difference in the risk of melanoma is shared across ethnic groups and is perhaps independent of UV behavior.

CONCLUSIONS

Our results highlight the importance of gender as one of the melanoma risk factors beyond traditional UV radiation, which warrants further investigation and may provide a base for an improved prevention strategy.

Age-dependent interaction between sex and geographic ultraviolet index in melanoma risk

BACKGROUND

Ultraviolet (UV) exposure may not affect melanoma development equally in different sexes and ages. Whether and how these factors interact with each other in relation to melanoma risk is unknown.

OBJECTIVE

This study attempts to estimate interactions among UV index (UVI), sex, and age in melanoma risk.

METHODS

Melanoma incidence data were collected from 42 cancer registries. Geographic UVI was collected from local satellite stations. Negative binomial regression models were used to estimate the impact of each risk factor and their interactions.

RESULTS

Sex, UVI, and age, as well as interactions between any 2 of these factors, were significantly associated with melanoma risk. In younger age groups, female sex is an independent risk factor for melanoma that is not affected by ambient UV exposure. In older age groups, however, female sex interacts with UV exposure as a risk factor, exhibiting a protective effect. The switching age category is 45 to 49, which correlates with dramatic hormonal changes.

LIMITATIONS

The interaction between sex and UVI is measured at an ecologic level.

CONCLUSIONS

The interaction between sex and UVI is age dependent. Female sex is an independent risk factor for early-onset melanoma, but female sex also protects against UV-associated melanoma in older age groups.