Hypothesis: hair cover can protect against invasive melanoma on the head and neck (Australia)

Pathogenic mechanisms and etiologic aspects of Mycobacterium avium subspecies paratuberculosis as an infectious cause of cutaneous melanoma

Infectious etiologies have previously been proposed as causes of both melanoma and non-melanoma skin cancer. This exploratory overview explains and presents the evidence for the hypothesis that a microorganism excreted in infected ruminant animal feces, Mycobacterium avium subspecies paratuberculosis (MAP), is the cause of some cases of cutaneous melanoma (CM). Occupational, residential, and recreational contact with MAP-contaminated feces, soil, sand, and natural bodies of water may confer a higher rate of CM. Included in our hypothesis are possible reasons for the differing rates and locations of CM in persons with white versus nonwhite skin, why CM develops underneath nails and in vulvar skin, why canine melanoma is an excellent model for human melanoma, and why the Bacille Calmette-Guérin (BCG) vaccine has demonstrated efficacy in the prevention and treatment of CM. The pathogenic mechanisms and etiologic aspects of MAP, as a transmittable agent underlying CM risk, are carefully deliberated in this paper. Imbalances in gut and skin bacteria, genetic risk factors, and vaccine prevention/therapy are also discussed, while acknowledging that the evidence for a causal association between MAP exposure and CM remains circumstantial.

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.

Diagnosis and Management of Melanoma of the Scalp: A Review of the Literature

Cutaneous melanoma is a public health issue and the head and neck region is of particular interest, despite accounting for only 9.0% of the total body surface, it harbours 20% of melanoma cases. Data from the literature show that scalp melanomas (SM) carry high mortality rates, with a 10-year survival rate of 60% which lead them to be named as the “invisible killer”. Moreover, SMs are more common in the elderly than in young population, and they occur six times more frequently in men than in women. This is probably related to the higher incidence of androgenetic alopecia and a higher cumulative and intermittent ultraviolet damage on the scalp. Histologically, SM is a heterogenous group, including lentiginous melanoma (LM), desmoplastic melanoma, superficial spreading and nodular melanoma. Thin melanomas tend to display an atypical network or pseudo-network and regression in dermoscopy. Blue-white veil, irregular pigmented blotches and an unspecific pattern are most commonly detected in thick lesions. On reflectance confocal microscopy (RCM), the most frequent pattern is irregular meshwork, but also ringed and disarranged pattern have been described. Differential diagnosis includes benign solar lentigo, actinic keratoses, lichen planus like keratosis, melanocytic nevi and blue nevi. All suspicious lesions should be biopsied; therefore, an excisional biopsy with 2 mm margins is usually the best option. The management of SM is the same as for melanoma on other body sites. However, sentinel node biopsy tends to be more challenging, as well as achieving adequate excision margins of the primary tumor. In this review, we summarize clinical, pathologic, dermoscopic and RCM features of SM, and focus on its epidemiology, risk factors and best management options.

Age and Cohort Trends of Malignant Melanoma in the United States

Simple Summary

The occurrence of melanoma in the United States is increasing over time. We examined trends in melanoma by birth year and age groups to determine if individuals born more recently experience higher rates of melanoma as they age. We examined these trends separately among men and women and by the location on the body that the melanoma occurred. Melanoma incidence has continued to increase across more recent birth years and varies by body site and sex. Melanoma incidence will likely continue to increase as younger individuals age. While these are mostly thin melanomas, treatment to prevent cancer progression is still costly, both economically and emotionally, for patients.

Abstract

The incidence of malignant melanoma in the United States is increasing, possibly due to changes in ultraviolet radiation (UVR) exposure due to lifestyle or increased awareness and diagnosis of melanoma. To determine if more recent birth cohorts experience higher rates of melanoma as they age, we examined age and birth cohort trends in the United States stratified by anatomic site and cancer type (in situ vs. malignant) of the melanoma diagnosed from 1975–2017. Poisson regression of cutaneous melanoma cases per population for 1975–2017 from the Surveillance, Epidemiology, and End Results (SEER) cancer registries was used to estimate age adjusted incidence for five-year birth cohorts restricted to Whites, ages 15–84. The rate of melanoma incidence across birth cohorts varies by anatomic site and sex. Melanomas at all anatomic sites continue to increase, except for head and neck melanomas in men. Much of the increase in malignant melanoma is driven by cases of thin (<1.5 mm) lesions. While increased skin exams may contribute to the increased incidence of in situ and thin melanoma observed across birth cohorts, the shifts in anatomic site of highest melanoma incidence across birth cohorts suggest changes in UVR exposure may also play a role.

Sex- and Site-Related Significance in Cutaneous Head and Neck Melanoma

Cutaneous head and neck melanoma is a separate subgroup of cutaneous melanoma that has a worse prognosis than other primary sites. The aim of this article is to examine the significance of sex and site of primary lesion as additional risk factors. Primary localization distribution and metastatic disease in the neck in a retrospective cohort of 159 patients with cutaneous head and neck malignant melanoma were analyzed. Men develop primary melanoma more frequently than women in the left peripheral head and neck regions (P = .0364), as well as clinically visible and occult metastatic disease in the left side of the neck (P = .0138). Patients with clinically occult regional metastatic disease showed a significantly poorer survival rate than the rest of the group that underwent elective neck dissections (P = .0270). Left-sided disease in male patients may be an additional risk factor in cutaneous head and neck melanoma. Performing elective neck dissections in high-risk patients might identify patients with occult metastatic disease and worse prognosis but does not offer any significant therapeutic benefit.

Differences in site-specific incidence and relative survival of cutaneous and mucocutaneous genital squamous cell carcinoma in Germany, 2007-2015

Direct comparisons of the incidence and survival of cutaneous vs mucocutaneous genital squamous cell carcinomas (SCCs) are lacking even though they may bring important insights. We aimed to compare incidence rates and survival of cutaneous and mucocutaneous genital SCCs head-to-head, using the same source population, cancer registry methodology and statistical methods in a population of predominantly white Caucasian descent. Using data (2007-2015) from the population-based cancer registry of North Rhine-Westphalia, (population of 18 million people), we estimated age-specific and age-standardized (old European standard) incidence rates and age-standardized relative 5-year survival of SCC with the period approach for the period 2012 to 2015. Overall, 83 650 SCC cases were registered. The age-standardized incidence rates (per 100 000 person-years) of cutaneous SCCs were 36.5 (SE 0.17) and 17.0 (SE 0.11) among men and women, respectively, with corresponding rates for mucocutaneous genital skin, 1.3 (SE 0.03) and 4.5 (SE 0.06) for men and women, respectively. In all age groups, incidence rates of mucocutaneous genital SCCs were higher in women than men. Men had higher cutaneous SCC incidence at all nongenital subsites than women, with the exception of the lower extremities. Five-year relative survival was considerably lower for mucocutaneous genital SCCs (men: 71%, women: 75%), especially of the scrotal skin (67%) and labia majora (62%) than for SCC of nongenital skin (men: 93%, women: 97%). Given their relatively high incidence together with a lower survival probability, future studies are warranted to establish therapies for advanced mucocutaneous genital SCC, such as immune checkpoint inhibition.

A brief synopsis on scalp melanoma

Melanoma constitutes one of the most sinister and troublesome malignancies encountered by humanity. Generally, the diagnosis of advanced melanoma connotes a grave prognosis, prompting a sense of looming threat of death, however, the early-stage detected disease responds well to robust treatment resulting in reasonable survivorship. Scalp melanomas are even more troublesome, because they typically exhibit more aggressive biologic behavior and are often diagnosed at a late stage. This review tries to comprehensively highlight the various diagnostic, therapeutic, and outcome aspects of scalp melanomas. The literature research includes peer-reviewed articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) till May 2020 and reference lists of respective articles. Only articles published in English language were included.

The anatomic distribution of cutaneous melanoma: A detailed study of 5141 lesions

BACKGROUND/OBJECTIVES

There is evidence that cutaneous melanomas at different anatomic sites present with distinctive clinicopathologic features. We examined the anatomic distribution of cutaneous melanoma and its variation by patient characteristics, subtype and Breslow thickness, using high-resolution anatomic site data.

METHODS

A cross-sectional study was performed of all primary cutaneous melanoma cases managed at a tertiary referral centre, analysing prospectively collected clinical data across 50 anatomic subsites.

RESULTS

The study included 5141 in situ or invasive melanomas; most were invasive (76.2%), and the median Breslow thickness of invasive lesions was 1.0 mm. Superficial spreading (57.2%), lentigo maligna (20.8%) and nodular (12.2%) were the most common histopathological subtypes. Sun-exposed sites such as the female nose and cheek, the male ear, as well as the upper back in both sexes had the highest incidence of melanoma per unit area. When compared to the posterior forearm, the scalp, ear, preauricular, perioral, subungual and plantar sites had thicker invasive melanomas (each P < 0.05). The peri-auricular, ear and cheek had the highest incidence of nodular melanoma per unit area. There were subtype-, age- and sex-specific differences in melanoma anatomic distribution.

CONCLUSION

Melanoma most commonly arises in sun-exposed facial areas, as well as the upper back. Increased thickness is found for melanoma in acral and many head and neck sites. Nodular melanoma is more likely to occur in head and neck sites including the peri-auricular area, ear and cheek. Clinicians should carefully assess these sites during skin examinations.

Melanoma of the External Auditory Canal: A Review of Seven Cases at a Tertiary Care Referral Center

OBJECTIVES/HYPOTHESIS

Examine the presentation and management characteristics of seven patients with melanoma of the external auditory canal (EAC).

STUDY DESIGN

Retrospective case series and review of the relevant literature.

METHODS

Records of seven patients from 2003 to 2017 with melanoma of the EAC were reviewed for characteristics of presentation, subsequent management, and outcomes. A thorough review of relevant literature is presented.

RESULTS

The median age is 52 years, with four females. The average Breslow depth was 3.6 mm, with five patients having a Clark level IV or greater on presentation. Six patients underwent lateral temporal bone resection, and one patient underwent wide local excision of the cartilaginous canal. Sentinel lymph node biopsy (SLNB) was performed in three patients. Three patients experienced distant recurrence an average of 20 months following primary therapy. Median follow-up was 21 months. At last follow-up, four were free of disease, one had active disease, and two were deceased from melanoma.

CONCLUSIONS

This is the largest series and the first to report the use of SLNB for patients with EAC melanoma in the peer-reviewed literature. Patients with external auditory canal melanoma present with higher Breslow thickness and stage relative to all external ear melanomas. Management should include wide local excision, which entails lateral temporal bone resection when the bony ear canal is involved. SLNB has a critical role in identifying patients with early metastatic disease. Postoperative radiation therapy should be considered for patients with high-risk features to reduce the risk of locoregional relapse. Chemotherapy, and especially immunotherapy, has an emerging role for this disease.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:165-172, 2021.

Head and Neck Melanoma Incidence Trends in the Pediatric, Adolescent, and Young Adult Population of the United States and Canada, 1995-2014

Importance

Melanoma is one of the most common cancers worldwide, typically diagnosed in older adults. There is an increasing incidence in the younger population (age ≤40 years) in America. In addition, approximately 1 in 5 cases of melanoma affect the head and neck. However, there are limited data on the incidence of head and neck melanoma in the pediatric, adolescent, and young adult population in North America (United States and Canada).

Objective

To assess 20-year demographic and incidence changes associated with head and neck melanoma in the pediatric, adolescent, and young adult population in North America.

Design, Setting, and Participants

A descriptive analysis of retrospective data on head and neck melanoma from the North American Association of Central Cancer Registries' Cancer in North America public use data set from 1995 to 2014 was conducted. The data set currently includes 93% of the United States and 64% of the Canadian populations. Eligible data were from 12 462 pediatric, adolescent, and young adult patients (aged 0-39 years) with a confirmed diagnosis of melanoma (International Classification of Diseases-Oncology 3 histologic types 8720-8790) in primary head and neck sites: skin of lip, not otherwise specified (C44.0); eyelid (C44.1); external ear (C44.2); skin of other/unspecified parts of face (C44.3); and skin of scalp and neck (C44.4). The study was conducted from January 26 to July 21, 2019.

Main Outcomes and Measures

Log-linear regression was used to estimate annual percentage change in age-adjusted incidence rates (AAIRs) of head and neck melanoma.

Results

Of the 12 462 patients with head and neck melanoma included in the study, 6810 were male (54.6%). The AAIR was 0.51 per 100 000 persons (95% CI, 0.50-0.52 per 100 000 persons). In North America, the incidence of head and neck melanoma increased by 51.1% from 1995 to 2014. The rate was higher in the United States (AAIR, 0.52; 95% CI, 0.51-0.53 per 100 000 person-years) than Canada (AAIR, 0.43; 95% CI, 0.40-0.45 per 100 000 persons). In the United States, the incidence increased 4.68% yearly from 1995 to 2000 and 1.15% yearly from 2000 to 2014. In Canada, the incidence increased 2.18% yearly from 1995 to 2014. Male sex (AAIR, 0.55; 95% CI, 0.54-0.57 per 100 000 persons), older age (AAIR, 0.79; 95% CI, 0.79-0.80 per 100 000 persons), and non-Hispanic white race/ethnicity (AAIR, 0.79; 95% CI, 0.77-0.80 per 100 000 persons) were associated with an increased incidence of head and neck melanoma.

Conclusions and Relevance

The incidence of pediatric, adolescent, and young adult head and neck melanoma in North America appears to have increased by 51.1% in the past 2 decades, with males aged 15 to 39 years the main cohort associated with the increase.

Primary Locations of Malignant Melanoma Lesions Depending on Patients’ Gender and Age

Introduction: Location of malignant melanoma lesions depends on environmental, genetic, sociological and demographical factors. Available sources do not provide enough information on such dependencies in various populations. There is no data concerning the role of socio-demographic factors for the population of the Central and Eastern Europe. Aim: The aim of this work was to evaluate the anatomical location of the primary malignant melanoma lesion in correlation to patients’ gender and age. Material and methods: A retrospective analysis of medical documentation of 363 patients has been performed. The patients had been diagnosed with malignant melanoma and were undergoing treatment in the years 2010-2014 in two Polish oncologic hospitals. The subject group consisted of 199 (55%) females and 164 (45%) males. The age varied between 19 - 90 years, with the median of 62 years. Results: In women, the melanoma lesions seem to appear more often in their lower extremities, while in case of men such lesions seem to be more often on their torsos. In both cases, the difference was statistically significant (p<0.01 When the specific locations are considered in women the lesions were more often located on their shins (p<0.01), whereas for men the lesions were located on their backs (p<0.01). It has been observed that there is dependency between lesion localization and age of patients. The lesions located on heads and necks were most common in older patients, and the lesions located in lower extremities were most common in younger ones. Conclusion: Differences in location of malignant melanoma lesions may be due to either genetic or environmental reasons. It is often emphasized in literature that correlation between the socio-demographic factors and the process of oncogenesis requires intensive research. In our work, we have tried to fill this gap for the population of Central and Eastern Europe to determine the exact epidemiology of this kind of cancer. This knowledge may be then used for developing cancer prevention methods specific to gender and age.

Gender aspects of recreational sun-protective behavior: results of a representative, population-based survey among Austrian residents

PURPOSE

Lifetime risk for melanoma skin cancer is enlarged by sunlight exposure and reduced by sun protection. Austrian melanoma incidence and mortality rates are constantly rising with higher rates in males. Thus, we aimed at investigating gender-specific recreational sun exposure habits among the Austrian population.

METHODS

We conducted a telephone survey among 1500 adults (50.5% females) representing sociodemographic characteristics of the Austrian population. Using a structured questionnaire, we studied gender-specific sun exposure-related knowledge, motives to tan, and behavior.

RESULTS

Overall, using sunscreen, wearing sunglasses, and seeking shade were among the three most frequent sun safe measures. Basic skin health knowledge and tanning motives were similar among genders, although females protected themselves more. In general, sunburn occurrence (odds ratio [OR] = 1.4, 95% confidence interval [CI] = 1.0-1.8), skin type IV (OR = 2.4, 95% CI = 1.3-4.5), ex-/non-smoking (OR = 1.4-1.6, 95% CI = 1.0-2.1), low motives to tan (both OR = 1.3, 95% CI = 1.0-1.7), no outdoor sport (OR = 1.3, 95% CI = 1.0-1.7), all P < 0.05, as well as the use of sunscreen with lower SPF values (OR = 1.0-3.0, 95% CI = 1.4-4.3) and male gender (OR = 1.6, 95% CI = 1.2-2.0), both P < 0.001, increased the odds of practicing low sun protection.

CONCLUSION

The results of this investigation suggest considering gender specificity when planning Public (Skin) Health-related educative campaigns and programs, for example, by highlighting the appearance-related benefits of sun light avoidance.

Human Hair as a Natural Sun Protection Agent: A Quantitative Study

The rising incidence of skin cancers attributable to excessive sun exposure has become a major health concern worldwide. While numerous studies have analyzed the sun protective effect of sunscreens, clothing and antioxidants, none to date have measured the photoprotective effect of hair, despite clinical evidence that individuals with balding or thinning hair are at greater risk of skin lesions that can progress to cancer, hence the recommendation to use hats or umbrellas. We analyzed the level of protection offered by hair according to hair density, thickness and color using the spectral transmittance and corrected for relative erythema effectiveness. Our results show that hair provides a barrier against both UVB and UVA radiation which is significantly increased with respect to the hair density, thickness and the presence of melanins. This is the first study to quantify sun protection factor offered by hair, namely hair ultraviolet protection factor (HUPF). We believe that hair should be recognized as an important natural sun barrier in the prevention of UV-induced skin cancers.

Is sex an independent prognostic factor in cutaneous head and neck melanoma?

OBJECTIVES/HYPOTHESIS

To determine if sex independently affects disease-specific survival (DSS) in patients with cutaneous head and neck melanoma.

STUDY DESIGN

Retrospective analysis of a large population database.

METHODS

Our study included patients in the Surveillance, Epidemiology, and End Results database with cutaneous head and neck melanoma diagnosed from 2004 to 2009. Any cases with a history of previous malignancy or with multiple primaries were excluded. We obtained data on stage, race, age at diagnosis, radiological treatment status, and surgical treatment status. Our analysis consisted of a Kaplan-Meier analysis of DSS by sex [correction made here after initial online publication] that was supported by a multivariate Cox regression of all significant variables studied.

RESULTS

There were 13,507 patients identified with cutaneous head and neck melanoma who were diagnosed between 2004 and 2009. We observed that female patients had a better prognosis than their male counterparts, with 5-year DSS of 90.40% (95% confidence interval [CI], 89.03%-91.72%) and 87.10% (95% CI, 86.12%-88.08%), respectively. Multivariable analysis demonstrated a statistically significant decrease in disease-specific hazard ratio due to female sex independent of stage, treatment, age, or race.

CONCLUSIONS

Our study concludes that female sex is an independent prognostic factor for cutaneous head and neck melanoma. We demonstrated better 5-year DSS in female compared to male patients. Better prognosis could be due to multiple factors including differing hair, levels of sun exposure, and advanced male age.

LEVEL OF EVIDENCE

2b.

Sex-related location of head and neck melanoma strongly argues for a major role of sun exposure in cars and photoprotection by hair

Head and neck melanomas (HNMs) are frequent and have a poorer prognosis than melanomas at other sites. Photoprotection in these locations is difficult. In this population-based study of 279 HNMs diagnosed in a French region between 2004 and 2009, major differences were found between genders. A clearcut, sex-related distribution was found between a "peripheral" area (scalp, forehead, temples, ears, and neck) and a "central" one (other parts of the face), with 56.7% of HNMs being located in the peripheral area in men and 79.3% in the central area in women (P<0.0001). Moreover, HNMs located in the peripheral area occurred on the left side in 57.6% of men and on the right side in 73.1% of women (P=0.009). Peripheral HNMs differed from central HNMs by a higher proportion of invasive tumors, nodular or superficial spreading melanomas, and a lower proportion of lentigo maligna melanomas (LMMs). We hypothesized that this differential distribution between men and women could be explained mostly by a major role of long-term photoprotection by hair and sun exposure in a car. Important public health messages could result from these observations, such as the role of hairstyles in melanoma prevention and the importance of reducing sun exposure in a car, particularly in professional drivers.

Dosimetric investigation of the solar erythemal UV radiation protection provided by beards and moustaches

A dosimetric technique has been employed to establish the amount of erythemal ultraviolet radiation (UVR) protection provided by facial hair considering the influence of solar zenith angle (SZA) and beard-moustache length. The facial hair reduced the exposure ratios (ERs) to approximately one-third of those to the sites with no hair. The variation in the ERs over the different sites was reduced compared with the cases with no beard. The ultraviolet protection factor (UPF) provided by the facial hair ranged from 2 to 21. The UPF decreases with increasing SZA. The minimum UPF was in the 53-62° range. The longer hair provides a higher UPF at the smaller SZA, but the difference between the protection provided by the longer hair compared with the shorter hair reduces with increasing SZA. Protection from UVR is provided by the facial hair; however, it is not very high, particularly at the higher SZA.

Incidence of basal cell carcinoma multiplicity and detailed anatomic distribution: longitudinal study of an Australian population

A proportion of individuals are affected multiple times by basal cell carcinoma (BCC), but the rate and extent to which this occurs is unknown. We therefore prospectively estimated BCC incidence in a subtropical Australian population, focusing on the rate at which persons develop multiple primary BCCs and the precise anatomic sites of BCC occurrence. Between 1997 and 2006, 663 BCCs were confirmed in 301 of 1,337 participants in the population-based Nambour Skin Cancer Study. The incidence of persons affected multiple times by primary BCC was 705 per 100,000 person years compared to an incidence rate of people singly affected of 935 per 100,000 person years. Among the multiply and singly affected alike, site-specific BCC incidence rates were far highest on facial subsites, followed by upper limbs, trunk, and then lower limbs. We conclude that actual BCC tumor burden is much greater in the population than is apparent from normal incidence rates. Anatomic distribution of BCC is consistent with general levels of sun exposure across body sites.