Recent trends in incidence of cutaneous melanoma among US Caucasian young adults

Sentinel lymph node staging of cutaneous melanoma: predictors and outcomes

BACKGROUND

The authors updated their experience with sentinel lymph node (SLN) biopsy of clinically node negative (N0) melanoma to clarify indications, predictive factors, and outcomes.

METHODS

A review of patients from the authors' institution's prospective database (n = 397) was performed; survival statistics were obtained from the institutional tumor registry.

RESULTS

The SLN-positive (SLN+) rate was 16% (47 of 282) for lesions >1 mm thick; only 2 of 105 T1 lesions were SLN+. Thickness >2 mm, upper extremity primary, and ulceration predicted SLN+ status. Most SLN+ patients underwent completion node dissection; 12% had additional positive nodes. The false-negative SLN biopsy rate was 4.0%; the majority involved lower extremity and head and neck primaries. The overall complication rate was 26%; all were minor and resolved within 6 months. Overall 5-year survival rates were 73% and 92% for SLN+ and SLN-negative patients, respectively. SLN status was the most significant predictor of survival.

CONCLUSIONS

SLN status, the most important determinant of outcome for clinically N0 melanoma, correlated with T stage, ulceration, and site. Staging of T1 lesions had low yield. A minority of completion node dissections yielded additional positive nodes.

Melanocortin 1 receptor genotype: an important determinant of the damage response of melanocytes to ultraviolet radiation

The melanocortin 1 receptor gene is a main determinant of human pigmentation, and a melanoma susceptibility gene, because its variants that are strongly associated with red hair color increase melanoma risk. To test experimentally the association between melanocortin 1 receptor genotype and melanoma susceptibility, we compared the responses of primary human melanocyte cultures naturally expressing different melanocortin 1 receptor variants to α-melanocortin and ultraviolet radiation. We found that expression of 2 red hair variants abolished the response to α-melanocortin and its photoprotective effects, evidenced by lack of functional coupling of the receptor, and absence of reduction in ultraviolet radiation-induced hydrogen peroxide generation or enhancement of repair of DNA photoproducts, respectively. These variants had different heterozygous effects on receptor function. Microarray data confirmed the observed differences in responses of melanocytes with functional vs. nonfunctional receptor to α-melanocortin and ultraviolet radiation, and identified DNA repair and antioxidant genes that are modulated by α-melanocortin. Our findings highlight the molecular mechanisms by which the melanocortin 1 receptor genotype controls genomic stability of and the mutagenic effect of ultraviolet radiation on human melanocytes.

Gene expression profiling-based identification of molecular subtypes in stage IV melanomas with different clinical outcome

PURPOSE

The incidence of malignant melanoma is increasing worldwide in fair-skinned populations. Melanomas respond poorly to systemic therapy, and metastatic melanomas inevitably become fatal. Although spontaneous regression, likely due to immune defense activation, rarely occurs, we lack a biological rationale and predictive markers in selecting patients for immune therapy.

EXPERIMENTAL DESIGN

We performed unsupervised hierarchical clustering of global gene expression data from stage IV melanomas in 57 patients. For further characterization, we used immunohistochemistry of selected markers, genome-wide DNA copy number analysis, genetic and epigenetic analysis of the CDKN2A locus, and NRAS/BRAF mutation screening.

RESULTS

The analysis revealed four distinct subtypes with gene signatures characterized by expression of immune response, pigmentation differentiation, proliferation, or stromal composition genes. Although all subtypes harbored NRAS and BRAF mutations, there was a significant difference between subtypes (P < 0.01), with no BRAF/NRAS wild-type samples in the proliferative subtype. Additionally, the proliferative subtype was characterized by a high frequency of CDKN2A homozygous deletions (P < 0.01). We observed a different prognosis between the subtypes (P = 0.01), with a particularly poor survival for patients harboring tumors of the proliferative subtype compared with the others (P = 0.003). Importantly, the clinical relevance of the subtypes was validated in an independent cohort of 44 stage III and IV melanomas. Moreover, low expression of an a priori defined gene set associated with immune response signaling was significantly associated with poor outcome (P = 0.001).

CONCLUSIONS

Our data reveal a biologically based taxonomy of malignant melanomas with prognostic effect and support an influence of the antitumoral immune response on outcome.

Nutritional approach to sun protection: a suggested complement to external strategies

The increasing incidence of skin cancer despite the use of externally applied sun protection strategies, alongside research showing that nutrients reduce photo-oxidative damage, suggest nutritional approaches could play a beneficial role in skin cancer prevention. Penetrating photo-oxidative ultraviolet A radiation reduces skin and blood antioxidants and damages cell components, including DNA. Dietary antioxidant vitamins, minerals, and phytochemicals in addition to n-3 polyunsaturated fatty acids, n-9 monounsaturated fatty acids, and low pro-inflammatory n-6 polyunsaturated fatty acids, have demonstrated protective properties. The presence of these elements in the traditional Greek-style Mediterranean diet may have contributed to the low rates of melanoma in the Mediterranean region despite high levels of solar radiation. This suggests a potentially relevant model for studying dietary/nutritional supplementation for lifelong internal support of sun-protection mechanisms, which could complement external strategies.

Dendritic cell vaccination as a treatment modality for melanoma

As melanoma is an immunogenic tumor, immunotherapy has been investigated as a possible treatment modality for melanoma patients at high risk of relapse and those with metastatic disease. In the past decade progress has been made, ranging from rather nonspecific stimulations of the immune system with IL-2 and IFN-alpha to more specific approaches based on vaccination with tumor antigens. Owing to their unique features, dendritic cells (DCs) represent an important tool for tumor antigen-specific immunotherapy. However, clinical vaccination trials with DCs showed sobering results with respect to objective responses and improvement of overall survival. In this review, principles and methods of DC-based vaccination are presented. Mechanisms impairing clinically successful vaccination strategies are described. Finally, we will discuss perspectives for future developments of DC-based vaccines that might lead melanoma treatment to a new era.

Pregnancy is Not Detrimental to the Melanoma Patient with Clinically Localized Disease

OBJECTIVE

There exists a strong belief among physicians and the lay public that pregnancy adversely affects survival in patients with melanoma. The authors asked if there was any evidence to support this in patients with clinically localized disease.

METHODS

The authors reviewed the published literature on MEDLINE.

RESULTS

The authors found no compelling evidence in the literature that pregnancy has a negative impact on survival in patients with clinically localized cutaneous melanoma. Two recent population-based studies reported no negative impact of pregnancy on survival when pregnant melanoma patients were compared to nonpregnant gender-matched controls. A small increased risk of cause-specific death was noted in a recent population-based study, though this effect was small (HR, 1.52, p=0.47) and pregnant patients were more likely to have axial primary sites, which are associated with a poorer outcome.

CONCLUSION

There is no compelling evidence that pregnancy adversely affects outcome in melanoma patients who have clinically localized disease. Continuing to recommend a delay in childbearing for these patients is not supported by the published medical literature.

A comparison of the efficacy of an appearance-focused skin cancer intervention within indoor tanner subgroups identified by latent profile analysis

The reduction of intentional exposure to ultraviolet (UV) radiation is an important area of skin cancer prevention. Hillhouse et al. (Cancer 113:3257-3266, 2008) have developed an appearance-focused intervention with evidence of efficacy in lowering indoor tanning UV exposure in young women. In the current study, a subgroup approach was used to determine moderators of intervention efficacy. Undergraduate females in two regions of the United States (n = 362) were randomized into an intervention or control condition. Latent profile analysis was used to identify subgroups of indoor tanners based on patterns of indoor tanning motives. Intervention efficacy was examined within each subgroup. We found evidence for 4 subgroups of tanners: knowledgeable-appearance tanners, low-knowledge tanners, low-knowledge, relaxation tanners, and knowledgeable, low-appearance and low-relaxation tanners. The intervention significantly reduced indoor tanning for the low-knowledge subgroup (34% of the sample). The utility of the subgroup approach in developing targeted behavioral skin cancer interventions is discussed.

UVA tanning is involved in the increased incidence of skin cancers in fair-skinned young women

Melanomas are the most prevalent cancers in 25-29 yr old females and compose roughly 12% of cancers in 20-40 yr old women; under the age of 40, women have a higher incidence of melanomas than do men. Within the past few decades, the alarming trend to use commercial sunlamps for cosmetic pigmentation is of particular concern, especially since 71% of those patrons are women with 50% of patrons under the age of 29. A major problem may be the use of UVA-rich sunlamps which produce a visible tan but afford little to no protection from subsequent UV exposure. We hypothesize that the additional exposure of adolescents to unnaturally large amounts of UVA from artificial UV sources is implicated in the increasing incidence of malignant melanomas disproportionately in young women.

Targeted depletion of Polo-like kinase (Plk) 1 through lentiviral shRNA or a small-molecule inhibitor causes mitotic catastrophe and induction of apoptosis in human melanoma cells

Melanoma, one of the most lethal forms of skin cancer, remains resistant to currently available treatments. Therefore, additional target-based approaches are needed for the management of this neoplasm. Polo-like kinase 1 (Plk1) has been shown to be a crucial regulator of mitotic entry, progression, and exit. Elevated Plk1 level has been associated with aggressiveness of several cancer types and with poor disease prognosis. However, the role of Plk1 in melanoma is not well established. Here, we show that Plk1 is overexpressed in both clinical tissue specimens and cultured human melanoma cells (WM115, A375, and HS294T) when compared with normal skin tissues and cultured normal melanocytes, respectively. Furthermore, Plk1 gene knockdown through Plk1-specific shRNA or its activity inhibition by a small-molecule inhibitor resulted in a significant decrease in the viability and growth of melanoma cells without affecting normal human melanocytes. In addition, Plk1 inhibition resulted in a significant (i) decrease in clonogenic survival, (ii) multiple mitotic errors, (iii) G(2)/M cell-cycle arrest, and (iv) apoptosis of melanoma cells. This study suggests that Plk1 may have a functional relevance toward melanoma development and/or progression. We suggest that the targeting of Plk1 may be a viable approach for the treatment of melanoma.

Youth access to artificial UV radiation exposure: practices of 3647 US indoor tanning facilities

OBJECTIVE

To assess indoor tanning facility practices in a sample of facilities in 116 cities representing all 50 states.

DESIGN

Cross-sectional study.

SETTING

United States.

PARTICIPANTS

Employees of 3647 indoor tanning facilities were contacted by telephone. Data collectors (ie, confederates) posed as prospective, fair-skinned, 15-year-old female customers who had never tanned before.

MAIN OUTCOME MEASURES

Confederates asked respondents about their facility's practices related to parental consent, parental accompaniment, and allowable tanning session frequency.

RESULTS

Approximately 87% of the facilities required parental consent, 14% required parental accompaniment, 5% said they would not allow the confederate to tan owing to her age, and 71% would allow tanning every day the first week of indoor tanning. In Wisconsin, which bans indoor tanning among those younger than 16 years, 70% of facilities would not allow the confederate to tan. Multivariate analyses indicated that facilities in states with a youth access law were significantly more likely to require parental consent (P <.001) and parental accompaniment (P <.001) than those in states without a youth access law. Law was not significantly related to allowable tanning frequency (P = .81). Conclusion We recommend that additional states pass youth access legislation, preferably in the form of bans.

Prognostic factors in metastatic melanoma patients treated with biochemotherapy and maintenance immunotherapy

BACKGROUND

With no U.S. Food and Drug Administration-approved standard therapy other than high-dose interleukin-2 and dacarbazine for metastatic melanoma, biochemotherapy has shown promise, with long-term survival in selected patients. We felt that the study of prognostic factors would determine which patients might benefit from this intensive therapy.

METHODS

One hundred thirty-five consecutive patients with metastatic melanoma treated with decrescendo biochemotherapy followed by maintenance immunotherapy over 5 years were retrospectively studied to determine the most important prognostic factors for both overall survival and progression-free survival.

RESULTS

The median overall survival (OS) time was 16.6 months, with 1-year and 5-year survival rates of 70% and 28%, respectively. The median progression-free survival (PFS) time was 7.6 months, with 15% of patients progression free at 5 years. PFS curves showed no relapses after 30 months, so remissions were durable. For OS, a performance status score of zero, normal lactate dehydrogenase (LDH) level, stage M1a, and nonvisceral sites of metastasis were favorable factors. The group with normal LDH levels and skin or nodes as one of their metastatic sites had a relatively good prognosis, with median survival time of 44 months and an estimated 5-year survival rate of 38%. Conversely, patients with an elevated LDH level without any skin or nodal metastases had a poor prognosis, with no long-term survivors.

CONCLUSIONS

Metastatic melanoma patients treated with biochemotherapy and maintenance immunotherapy who have either a normal LDH level or skin or nodes as one of their metastatic sites may have durable remissions of their disease, and this therapy should be studied further in these groups.

UVB and UVA initiate different pathways to p53-dependent apoptosis in melanocytes

The incidence of cutaneous malignant melanoma (CMM) has more than doubled in the past 25 years and continues to increase at over 3% per year across all age groups (Linos et al., this issue), and invasive and disseminated melanoma in young women has increased by almost 10% since 1992 (Purdue et al., 2008). Early detection and excision of CMM can result in successful treatment, but disseminated disease is resistant to current therapies and has a very poor prognosis (Garbe and Eigentler, 2007). Sunlight exposure is a major risk factor for melanoma. In this issue, Waster and llinger investigate the effects of UVB and UVA on melanocytes.

Melanoma epidemiology

Melanoma is a complex, heterogeneous cancer that continues to increase in incidence. Multiple studies have consistently identified major host and environmental risk factors for melanoma. Nevi, particularly dysplastic nevi, confer much higher risks than most pigmentary characteristics. Ultraviolet radiation exposure is the predominant environmental risk factor for melanoma. Recently, both rare high risk susceptibility genes and common polymorphic genes contributing to melanoma risk have been identified.

Environmental effects of ozone depletion and its interactions with climate change: progress report, 2008

After the enthusiastic celebration of the 20th Anniversary of the Montreal Protocol on Substances that Deplete the Ozone Layer in 2007, the work for the protection of the ozone layer continues. The Environmental Effects Assessment Panel is one of the three expert panels within the Montreal Protocol. This EEAP deals with the increase of the UV irradiance on the Earth's surface and its effects on human health, animals, plants, biogeochemistry, air quality and materials. For the past few years, interactions of ozone depletion with climate change have also been considered. It has become clear that the environmental problems will be long-lasting. In spite of the fact that the worldwide production of ozone depleting chemicals has already been reduced by 95%, the environmental disturbances are expected to persist for about the next half a century, even if the protective work is actively continued, and completed. The latest full report was published in Photochem. Photobiol. Sci., 2007, 6, 201-332, and the last progress report in Photochem. Photobiol. Sci., 2008, 7, 15-27. The next full report on environmental effects is scheduled for the year 2010. The present progress report 2008 is one of the short interim reports, appearing annually.

Chemoprevention of human actinic keratoses by topical DL-alpha-tocopherol

Prior research shows that topical application of free, nonfatty acid-conjugated vitamin E (DL-alpha-tocopherol) prevents skin cancer in mice, as well as immunosuppression induced by UVB radiation. This study investigated the chemopreventive potential of DL-alpha-tocopherol in humans through monitoring surrogate end point biomarkers in sun-damaged skin. Contralateral arms of healthy human volunteers with actinic keratoses (AK) were randomly assigned to receive either 12.5% DL-alpha-tocopherol or placebo in a crème base for 6 months. Changes in number of AKs, levels of p53 protein expression, proliferating cell nuclear antigen, and polyamines were assessed along with skin and systemic vitamin E levels. Following treatment, plasma concentration levels of DL-alpha-tocopherol were unchanged, but skin levels were highly elevated (P < 0.001). Levels of p53 and proliferating cell nuclear antigen did not change significantly, whereas number of AKs declined insignificantly in both placebo and treatment arms. Regression models showed significant decreases in putrescine, spermidine, spermine, and total polyamine concentrations following treatment. Topically applied DL-alpha-tocopherol was substantially absorbed in skin, but the 6-month application did not significantly reduce numbers of preexisting AKs on moderately to severely sun-damaged forearms. Increases in polyamine synthesis are expected during tumor initiation and promotion; conversely, the significant reductions in polyamine levels resulting from the topical DL-alpha-tocopherol application are consistent with reductions in tumorigenesis potential. Topical tocopherol did not normalize established sun-induced lesions, but DL-alpha-tocopherol-induced reductions in polyamine metabolism are consistent with the inhibition of skin squamous cell carcinogenesis as seen in previous human trials and animal models.

Melanoma biology and the promise of zebrafish

Advantageous organismal and technical attributes of the zebrafish are being increasingly applied to study cancer biology. Along with other tumor models, zebrafish that develop melanomas have been generated. In both genetics and phenotype, zebrafish melanomas are strikingly similar to their human counterparts. For this reason, studies in the zebrafish are poised to make significant contributions to melanoma biology. In this review, we summarize important features of human melanoma and discuss how the zebrafish can be used to address many questions that remain unanswered about this devastating disease.

Density of indoor tanning facilities in 116 large U.S. cities

BACKGROUND

U.S. adolescents and young adults are using indoor tanning at high rates, even though it has been linked to both melanoma and squamous cell cancer. Because the availability of commercial indoor tanning facilities may influence use, data are needed on the number and density of such facilities.

METHODS

In March 2006, commercial indoor tanning facilities in 116 large U.S. cities were identified, and the number and density (per 100,000 population) were computed for each city. Bivariate and multivariate analyses conducted in 2008 tested the association between tanning-facility density and selected geographic, climatologic, demographic, and legislative variables.

RESULTS

Mean facility number and density across cities were 41.8 (SD=30.8) and 11.8 (SD=6.0), respectively. In multivariate analysis, cities with higher percentages of whites and lower ultraviolet (UV)index scores had significantly higher facility densities than those with lower percentages of whites and higher UV index scores.

CONCLUSIONS

These data indicate that commercial indoor tanning is widely available in the urban U.S., and this availability may help explain the high usage of indoor tanning.

Teens and tanning knowledge and attitudes

BACKGROUND

The incidence of skin cancer, including melanoma, continues to increase. Teenagers are especially vulnerable, as are young females. The incidence of melanoma among young women in their twenties and thirties has begun to increase again. These young people are also the population that frequent tanning salons.

OBJECTIVE

This voluntary, anonymous, New York University, Institutional Review Board-approved survey was given to students in grades 9 through 12 to ascertain their understanding of what causes skin cancers and the dangers of excessive sun exposure and tanning salons.

METHODS AND MATERIALS

An Institutional Review Board-approved, 22-question survey was administered anonymously to more than 450 students with 368 returned responses. The survey was administered to students in grades 9 through 12 at two high schools in New York and New Jersey.

RESULTS

More than 80 percent of students view movie stars as tan and almost 60 percent see "tan" people as better looking. In addition, more than 90 percent believe that a tan does not prevent further damage to the skin (as opposed to the customary belief that a "base" tan can protect against extreme sun exposures, such as when on a tropical vacation). There appears to be a disconnect between knowledge and sun tanning behaviors. Most teenagers still believe that tans are attractive and teenage girls continue to use tanning salons and tan naturally. We need to address the connection between sun tanning in youth and skin cancers years later. Legislation to limit access of tanning salons to teenagers needs to be enacted.

Are tanning beds "safe"? Human studies of melanoma

Controversy continues over the carcinogenic properties of tanning beds. The tanning industry "sells" tanning beds as a safe alternative to UV exposure for both tanning as well as vitamin D biosynthesis. But, how safe are tanning beds? Epidemiologic data - incomplete and unsatisfactory - suggests that tanning beds are not safer than solar ultraviolet radiation and that they may have independent effects from solar exposure that increase risk for melanoma.