Melanoma in Maori, Asian, and Pacific Peoples in New Zealand

Dynamic ctDNA Mutational Complexity in Patients with Melanoma Receiving Immunotherapy

BACKGROUND

Circulating tumour DNA (ctDNA) analysis promises to improve the clinical care of people with cancer, address health inequities and guide translational research. This observational cohort study used ctDNA to follow 29 patients with advanced-stage cutaneous melanoma through multiple cycles of immunotherapy.

METHOD

A melanoma-specific ctDNA next-generation sequencing (NGS) panel, droplet digital polymerase chain reaction (ddPCR) and mass spectrometry analysis were used to identify ctDNA mutations in longitudinal blood plasma samples from Aotearoa New Zealand (NZ) patients receiving immunotherapy for melanoma. These technologies were used in conjunction to identify the breadth and complexity of tumour genomic information that ctDNA analysis can reliably report.

RESULTS

During the course of immunotherapy treatment, a high level of dynamic mutational complexity was identified in blood plasma, including multiple BRAF mutations in the same patient, clinically relevant BRAF mutations emerging through therapy and co-occurring sub-clonal BRAF and NRAS mutations. The technical validity of this ctDNA analysis was supported by high sample analysis-reanalysis concordance, as well as concordance between different ctDNA measurement technologies. In addition, we observed > 90% concordance in the detection of ctDNA when using cell-stabilising collection tubes followed by 7-day delayed processing, compared with standard EDTA blood collection protocols with rapid processing. We also found that the undetectability of ctDNA at a proportion of treatment cycles was associated with durable clinical benefit (DCB).

CONCLUSION

We found that multiple ctDNA processing and analysis methods consistently identified complex longitudinal patterns of clinically relevant mutations, adding support for expanded clinical trials of this technology in a variety of oncology settings.

Remote Skin Cancer Diagnosis: Adding Images to Electronic Referrals Is More Efficient Than Wait-Listing for a Nurse-Led Imaging Clinic

Simple Summary

Skin cancer is a significant cause of death and disability, particularly in New Zealand. Expert diagnosis reduces unnecessary excision of benign lesions, reduces patient anxiety, and allows early identification of skin cancer, particularly of melanoma. The study assessed an electronic referral pathway for teledermatology—diagnosing skin lesions remotely using a standardised template with regional, close-up, and dermoscopic images—and compared this to scheduled nurse-led teledermoscopy clinics. A dermatology opinion was reached more rapidly with comparable efficacy when referrals include good quality images, compared to nurse-led imaging clinics.

Abstract

We undertook a retrospective comparison of two teledermatology pathways that provide diagnostic and management advice for suspected skin cancers, to evaluate the time from referral to diagnosis and its concordance with histology. Primary Care doctors could refer patients to either the Virtual Lesion Clinic (VLC), a nurse-led community teledermoscopy clinic or, more recently, to the Suspected Skin Cancer (SSC) pathway, which requires them to attach regional, close-up, and dermoscopic images. The primary objective of this study was to determine the comparative time course between the SSC pathway and VLC. Secondary objectives included comparative diagnostic concordance, skin lesion classification, and evaluation of missed skin lesions during subsequent follow-up. VLC referrals from July to December 2016 and 2020 were compared to SSC referrals from July to December 2020. 408 patients with 682 lesions in the VLC cohort were compared with 480 patients with 548 lesions from the 2020 SSC cohort, matched for age, sex, and ethnicity, including histology where available. Median time (SD) from referral to receipt of teledermatology advice was four (2.8) days and 50 (43.0) days for the SSC and VLC cohorts, respectively (p < 0.001). Diagnostic concordance between teledermatologist and histopathologist for benign versus malignant lesions was 70% for 114 lesions in the SSC cohort, comparable to the VLC cohort (71% of 122 lesions). Referrals from primary care, where skin lesions were imaged with variable devices and quality resulted in faster specialist advice with similar diagnostic performance compared to high-quality imaging at nurse-led specialist dermoscopy clinics.

The presenting features of melanoma in New Zealand: implications for earlier detection

OBJECTIVE

To examine the relationship between presenting features and histological characteristics of melanomas in New Zealand.

METHODS

Cases were participants in a national melanoma case-control study. Histological data were extracted from a Cancer Registry download. Associations between categorical variables were assessed using the χ2 test; linear regression was used for continuous variables and multinomial logistic regression for non-binary categorical dependent variables.

RESULTS

Most melanomas were self-detected. Lesions >2mm depth took longer to diagnose, predominantly due to patient delay. The commonest presenting feature was colour. After adjustment for depth, nodular melanomas were less likely than superficial spreading melanomas to present because of shape or colour, but more likely to be raised. After adjustment for subtype, thick melanomas were significantly more likely to be bigger, raised, bleeding or crusting, and inflamed, itchy or sore.

CONCLUSIONS

Nodular and thick melanomas failed to fulfil the ABCDE criteria: the 'A', 'B' and 'C' discriminated poorly; and 'D' for diameter may exclude small but thick lesions. The 'E' criterion (elevation/enlargement/evolution) was perhaps best for detecting these melanomas. Implications for public health: Public education for earlier diagnosis in New Zealand needs to include the presenting features of nodular and thick melanomas and to strongly encourage seeking early physician advice.

Successful melanoma triage by a virtual lesion clinic (teledermatoscopy)

BACKGROUND

A Virtual Lesion Clinic (VLC) using teledermatoscopy was established to improve efficiency of the melanoma referral pathway.

OBJECTIVES

To assess diagnostic accuracy and to compare wait-times and costs of VLC and conventional clinics.

METHODS

Patients with suspected melanoma referred from primary care into a publicly funded health system attended local skin imaging centres, rather than hospital outpatient clinics. A teledermatologist assessed each lesion choosing specialist assessment/excision, General Practitioner (GP) follow-up, to re-image in 3 months, or self-monitoring/no concern.

RESULTS

613 skin lesions in 310 patients were evaluated over 12 months. Median time between receipt of referral and attendance at the VLC was 9 days compared to 26.5 days for standard outpatient assessment. Sixty-six percent (404/613) of lesions were considered benign, and 12% (73/613) were suspicious for melanoma. Of 129 lesions excised, 98 were skin cancers including 48 histologically confirmed melanomas with one spitzoid tumour of unknown malignant potential (STUMP), i.e. one melanoma per 1.59 suspected lesions biopsied and one melanoma in every 12.8 referred to the service. There were 49 non-melanoma skin cancers (NMSC). Teledermatoscopic diagnosis of melanomas was found to have a positive predictive value (PPV) of 63%. Compared to the conventional clinic, cost reductions from running the VLC for 1 year were in excess of NZ$364,000 (or NZ$1174/patient seen).

CONCLUSIONS

The VLC offered an efficient, accurate and cost effective way of processing suspected melanoma referrals to the public health system.

Individual risk of cutaneous melanoma in New Zealand: developing a clinical prediction aid

Background

New Zealand and Australia have the highest melanoma incidence rates worldwide. In New Zealand, both the incidence and thickness have been increasing. Clinical decisions require accurate risk prediction but a simple list of genetic, phenotypic and behavioural risk factors is inadequate to estimate individual risk as the risk factors for melanoma have complex interactions. In order to offer tailored clinical management strategies, we developed a New Zealand prediction model to estimate individual 5-year absolute risk of melanoma.

Methods

A population-based case–control study (368 cases and 270 controls) of melanoma risk factors provided estimates of relative risks for fair-skinned New Zealanders aged 20–79 years. Model selection techniques and multivariate logistic regression were used to determine the important predictors. The relative risks for predictors were combined with baseline melanoma incidence rates and non-melanoma mortality rates to calculate individual probabilities of developing melanoma within 5 years.

Results

For women, the best model included skin colour, number of moles > =5 mm on the right arm, having a 1st degree relative with large moles, and a personal history of non-melanoma skin cancer (NMSC). The model correctly classified 68% of participants; the C-statistic was 0.74. For men, the best model included age, place of occupation up to age 18 years, number of moles > =5 mm on the right arm, birthplace, and a history of NMSC. The model correctly classified 67% of cases; the C-statistic was 0.71.

Conclusions

We have developed the first New Zealand risk prediction model that calculates individual absolute 5-year risk of melanoma. This model will aid physicians to identify individuals at high risk, allowing them to individually target surveillance and other management strategies, and thereby reduce the high melanoma burden in New Zealand.

The association of indoor tanning and melanoma in adults: systematic review and meta-analysis

BACKGROUND

Tanning beds are associated with increased risk of melanoma.

OBJECTIVE

We sought to update the evidence of the association of melanoma and indoor tanning focusing on frequency of use and exposure to newer tanning beds.

METHODS

We searched Scopus, MEDLINE, and Cumulative Index to Nursing and Allied Health Literature on August 14, 2013. We included all observational studies that included patients with melanoma who had indoor tanned. Odds ratios (OR) with 95% confidence intervals (CI) were extracted and combined using generic inverse variance methods assuming a random effects model.

RESULTS

In all, 31 studies were included with data available on 14,956 melanoma cases and 233,106 controls. Compared with never using, the OR for melanoma associated with ever using indoor tanning beds was 1.16 (95% CI 1.05-1.28). Similar findings were identified in recent studies with enrollment occurring in the year 2000 onward (OR 1.22, 95% CI 1.03-1.45) and in subjects attending more than 10 tanning sessions (OR 1.34, 95% CI 1.05-1.71).

LIMITATIONS

The quality of evidence contributing to review results ranges from poor to mediocre.

CONCLUSION

Using tanning beds is associated with a subsequent melanoma diagnosis. Exposure from more than 10 tanning sessions is most strongly associated and there was no statistically significant difference in this association before and after 2000, suggesting that newer tanning technology is not safer than older models.

Cancer incidence and soil arsenic exposure in a historical gold mining area in Victoria, Australia: a geospatial analysis

Soil and mine waste around historical gold mining sites may have elevated arsenic concentrations. Recent evidence suggests some systemic arsenic absorption by residents in the goldfields region of Victoria, Australia. Victorian Cancer Registry and geochemical data were accessed for an ecological geographical correlation study, 1984-2003. Spatial empirical Bayes smoothing was applied when estimating standardised incidence ratios (SIRs) for cancers in 61 statistical local areas. The derived soil arsenic exposure metric ranged from 1.4 to 1857 mg/kg. Spatial autoregressive modelling detected increases in smoothed SIRs for all cancers of 0.05 (95% confidence interval (CI), 0.02-0.08) and 0.04 (0.01-0.07) per 2.7-fold increase in the natural log-transformed exposure metric for males and females, respectively, in more socioeconomically disadvantaged areas; for melanoma in males (0.05 (0.01-0.08) adjusted for disadvantage) and females (0.05 (0.02-0.09) in disadvantaged areas). Excess risks were estimated for all cancers (relative risk 1.21 (95% CI, 1.15-1.27) and 1.08 (1.03-1.14)), and melanoma (1.52 (1.25-1.85) and 1.29 (1.08-1.55)), for males and females, respectively, in disadvantaged areas in the highest quintile of the exposure metric relative to the lowest. Our findings suggest small but significant increases in past cancer risk associated with increasing soil arsenic in socioeconomically disadvantaged areas and demonstrate the robustness of this geospatial approach.

Risk factors for malignant melanoma in white and non-white/non-African American populations: the multiethnic cohort

It is unknown whether the established risk factors for malignant melanoma in whites influence malignant melanoma risk in non-whites. We examined the risk factors for melanoma among 39,325 whites and 101,229 non-whites/multiracials [Japanese American (47.5%), Latino American (34.8%), Native Hawaiian (2.1%), and multiracial (15.6%), excluding African Americans] in the Multiethnic Cohort study. With an average follow-up of 12.7 years, 581 invasive malignant melanoma (IMM) and 412 melanoma in situ (MIS) cases were identified, of which 107 IMM and 74 MIS were among non-whites/multiracials. The relative risks (RR) and 95% confidence intervals (CI) were estimated by Cox proportional hazards models using days from cohort entry as the underlying time variable. Among non-white/multiracial males, location of IMM tumors differed from those of white males (P < 0.001); and non-white/multiracial females were more likely to be diagnosed with later stage of disease (P < 0.001). After adjusting for potential confounders, age at cohort entry, male sex, higher education, and sunburn susceptibility phenotypes were associated with an increased risk of IMM in non-whites/multiracials (P < 0.05). The risk estimates for age at cohort entry and lighter hair and eye color were greater in non-whites/multiracials than in whites (P(heterogeneity) = 0.062, 0.016, and 0.005, respectively). For MIS risk, RRs between whites and non-whites/multiracials also differed for study location and education (P(heterogeneity) ≤ 0.015). In conclusion, similar to whites, age at cohort entry, male sex, and susceptibility to sunburn phenotypes may be predictive of malignant melanoma risk in non-white populations excluding African Americans.

The risks and benefits of sun exposure: should skin colour or ethnicity be the main variable for communicating health promotion messages in New Zealand?

OBJECTIVE

Using New Zealand as a case study, to determine whether ethnicity is appropriate for communicating sun exposure health promotion messages.

DESIGN

This study reviews recent literature on minimising skin cancer risk and achieving sufficient serum vitamin D levels. It draws on a variety of scientific literature, reports and media statements to determine appropriate sun exposure messages for minimising skin cancer risk and achieving sufficient vitamin D status among the New Zealand population, which is diverse with regards to both ethnicity and skin colour.

RESULT(S)

Due to a unique combination of factors, New Zealand and Australia lead the world in melanoma incidence. Devising ways of minimising skin cancer risk and achieving optimal vitamin D blood levels among the New Zealand population provide major challenges for researchers and health promoters. These challenges include the many unknowns and uncertainties about vitamin D, such as determining what constitutes an optimal level as well as its association with specific diseases. There is strong evidence that skin cancer, including melanoma, is caused by excess harmful sun exposure with skin colour having long been established as a risk factor. More recently, there has been significant focus in New Zealand on the potential beneficial aspects of sun exposure, mainly in assisting vitamin D synthesis, especially for Maori and Pacific people. But research also shows that Maori and Pacific people are increasingly at risk of developing melanoma. In New Zealand, where there is a high rate of ethnic intermarriage and ethnicity is culturally constructed, there is likely to have been a weakening of the relationship between ethnicity and skin colour. Skin colour information is required to understand both the risks and benefits of sun exposure. In the immediate future, ethnicity appears likely to remain an important reference point for assessing the risks and benefits of sun exposure in New Zealand. However, we contend that while ethnic-based channels may be useful for communicating appropriate sun exposure messages, there are dangers in such advice based on membership of particular ethnic group(s). Rather skin colour, along with other key variables, such as season and time of day, should be the core considerations for assessing and discussing risk. In the longer term, direct measures of skin type are needed when assessing the risks and benefits of sun exposure, including the potential protective effects against various illnesses.

CONCLUSION

While ethnic-based dissemination channels may be useful for communicating about the risks and benefits of sun exposure in New Zealand, discussion of risk factors should focus on skin colour.

The human health effects of ozone depletion and interactions with climate change

Depletion of the stratospheric ozone layer has led to increased solar UV-B radiation (280-315 nm) at the surface of the Earth. This change is likely to have had an impact on human exposure to UV-B radiation with consequential detrimental and beneficial effects on health, although behavioural changes in society over the past 60 years or so with regard to sun exposure are of considerable importance. The present report concentrates on information published since our previous report in 2007. The adverse effects of UV radiation are primarily on the eye and the skin. While solar UV radiation is a recognised risk factor for some types of cataract and for pterygium, the evidence is less strong, although increasing, for ocular melanoma, and is equivocal at present for age-related macular degeneration. For the skin, the most common harmful outcome is skin cancer, including melanoma and the non-melanoma skin cancers, basal cell carcinoma and squamous cell carcinoma. The incidence of all three of these tumours has risen significantly over the past five decades, particularly in people with fair skin, and is projected to continue to increase, thus posing a significant world-wide health burden. Overexposure to the sun is the major identified environmental risk factor in skin cancer, in association with various genetic risk factors and immune effects. Suppression of some aspects of immunity follows exposure to UV radiation and the consequences of this modulation for the immune control of infectious diseases, for vaccination and for tumours, are additional concerns. In a common sun allergy (polymorphic light eruption), there is an imbalance in the immune response to UV radiation, resulting in a sun-evoked rash. The major health benefit of exposure to solar UV-B radiation is the production of vitamin D. Vitamin D plays a crucial role in bone metabolism and is also implicated in protection against a wide range of diseases. Although there is some evidence supporting protective effects for a range of internal cancers, this is not yet conclusive, but strongest for colorectal cancer, at present. A role for vitamin D in protection against several autoimmune diseases has been studied, with the most convincing results to date for multiple sclerosis. Vitamin D is starting to be assessed for its protective properties against several infectious and coronary diseases. Current methods for protecting the eye and the skin from the adverse effects of solar UV radiation are evaluated, including seeking shade, wearing protective clothing and sunglasses, and using sunscreens. Newer possibilities are considered such as creams that repair UV-induced DNA damage, and substances applied topically to the skin or eaten in the diet that protect against some of the detrimental effects of sun exposure. It is difficult to provide easily understandable public health messages regarding "safe" sun exposure, so that the positive effects of vitamin D production are balanced against the negative effects of excessive exposure. The international response to ozone depletion has included the development and deployment of replacement technologies and chemicals. To date, limited evidence suggests that substitutes for the ozone-depleting substances do not have significant effects on human health. In addition to stratospheric ozone depletion, climate change is predicted to affect human health, and potential interactions between these two parameters are considered. These include altering the risk of developing skin tumours, infectious diseases and various skin diseases, in addition to altering the efficiency by which pathogenic microorganisms are inactivated in the environment.

Clinical and histologic factors associated with melanoma thickness in New Zealand Europeans, Maori, and Pacific peoples

BACKGROUND

Thickness is the major prognostic indicator for patients with melanoma. In many countries, the incidence of thick melanoma has not decreased. To reduce mortality, knowledge of the characteristics associated with melanoma depth is needed.

METHODS

To examine the relation between melanoma thickness and other factors in Europeans, Maori, and Pacific peoples, the authors analyzed the 14,802 melanoma registrations in New Zealand between 1996 and 2006. Notifications of invasive cutaneous melanoma from 1996 to 2006 were extracted from the New Zealand Cancer Registry. Ethnicity was categorized using the Statistics New Zealand prioritization algorithm. The geometric mean tumor thickness was calculated using log-transformed Breslow depth. Multivariate linear regression was used to examine the relation of predictor variables, their interactions, and melanoma thickness.

RESULTS

Melanoma thickness increased by 1% per year from 1996 to 2006. Although melanoma is rare in Maori and Pacific peoples, after adjustment, melanoma thickness was significantly greater in those populations compared with Europeans. Among Europeans, melanoma thickness was associated significantly with age at diagnosis, year of registration, sex, histology subtype, and extent of disease at diagnosis. In Maori, thick melanomas were likely to be nodular and to have regional or lymph node spread. The most important determinant of melanoma thickness in Pacific peoples was body site.

CONCLUSIONS

Differences in melanoma thickness among ethnic groups were not explained fully by tumor subtype, site, or extent of disease. The current results indicated that the thicker melanomas in darker skinned populations probably can be accounted for in part by more aggressive lesions. Research is needed to identify additional characteristics to explain ethnic variations in melanoma thickness.

Questionnaire items to assess skin color and erythemal sensitivity: reliability, validity, and "the dark shift"

BACKGROUND

Skin pigmentation is a key factor for UV radiation exposure related cancers. To appropriately target cancer control activities related to this exposure and for better representation in epidemiologic studies, a valid and reliable assessment of skin color is required.

METHODS

The validity and reliability of two self-report measures were assessed: skin color and erythemal sensitivity. A sample of 289 university students categorized their unexposed skin color and photosensitivity via a questionnaire. Skin color was also measured by spectrophotometer. After 7 days, participants repeated the self-report assessment.

RESULTS

Significant correlations were found for both self-report items with objective measures, indicating that these items may be valid assessment tools (color: Spearman's rho=-0.75, P<0.001; photosensitivity: Spearman's rho=-0.64, P<0.001). No sex differences in validity were evident. Stronger correlations were found among those of European than those of non-European ethnicity (color: Spearman's rho=-0.78 versus -0.59, bootstrap P=0.007; photosensitivity: Spearman's rho=-0.63 versus -0.28, bootstrap P=0.001). Strong biases toward overestimation of skin pigmentation were evident, ranging from 36% in the self-identified fair skin group to 77% in the medium skin color group. Intrarater reliability of the questionnaire items was high (color: k=0.78, P<0.001; photosensitivity: k=0.77, P<0.001).

CONCLUSIONS

Study findings suggest that self-report may be a valid measurement strategy when assessing skin type, but there is a bias toward overestimation of skin color and, potentially, UV radiation resilience.

IMPACT

This bias has the potential to undermine the effectiveness of skin cancer prevention efforts and needs to be addressed in health promotion programs.

Environmental effects of ozone depletion and its interactions with climate change: progress report, 2009

The parties to the Montreal Protocol are informed by three panels of experts. One of these is the Environmental Effects Assessment Panel (EEAP), which deals with UV radiation and its effects on human health, animals, plants, biogeochemistry, air quality and materials. Since 2000, the analyses and interpretation of these effects have included interactions between UV radiation and global climate change. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than believed previously. As a result of this, human health and environmental problems will likely be longer-lasting and more regionally variable. Like the other panels, the EEAP produces a detailed report every four years; the most recent was that for 2006 (Photochem. Photobiol. Sci., 2007, 6, 201-332). In the years in between, the EEAP produces a less detailed and shorter progress report, as is the case for this present one for 2009. A full quadrennial report will follow for 2010.