Comparing the characteristics and predicting the survival of patients with head and neck melanoma versus body melanoma: a population-based study

Protocol to develop a chemotherapy drug screening process by constructing a cancer prognostic model using public databases

Drug resistance is currently the biggest challenge in cancer chemotherapy. Here, we present a protocol to develop a chemotherapy drug screening process by constructing a cancer prognostic model (PM) using public databases. We describe steps for downloading code and data, preparing the expression matrix and metadata for analysis, screening modeling genes, and constructing a PM. We then detail procedures for constructing predictive websites for cancer patients' survival based on their age, tumor stage, gene expression levels, and risk scores. For complete details on the use and execution of this protocol, please refer to Bai et al.1.

A Prognostic Model for Cancer-Specific Survival Among Patients with Nodular Melanoma in Head and Neck

OBJECTIVES

This study aims to evaluate the correlation between risk factors and treatment methods affecting nodular melanoma (NM) in the head and neck, as well as cancer-specific survival (CSS), and provide personalized predictive tools for clinical physicians.

METHODS

The retrospective study data of 1848 patients were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. All variables were included in the correlation analysis using the Spearman method. Significant prognostic factors were extracted and integrated through Cox risk regression analysis to construct a nomogram. To assess the performance of the nomogram, Harrell's concordance index (C-index) and a receiver operating characteristic (ROC) curve analysis were employed.

RESULTS

Spearman's correlation analysis revealed a positive correlation between radiotherapy and lymph node metastasis, whereas chemotherapy showed a stronger association with distant metastasis. However, Cox risk regression analysis demonstrated that Mohs surgery and wide excision with margins exceeding 1 cm yielded substantial therapeutic advantages. Five independent risk prognostic factors (Breslow thickness, ulceration, N classification, M classification, and surgery type) were employed to construct a nomogram. The C-index for this nomogram was 0.713 for the training set and 0.720 for the validation set. In the training set, the 3-, 5-, and 8-year areas under the curve (AUCs) for CSS were 0.752, 0.723, and 0.720, whereas the validation set's AUCs were 0.754, 0.763, and 0.760, respectively. Calibration curves indicated the nomogram's strong discriminative ability for predicting CSS.

CONCLUSION

In this study, we identified independent prognostic factors for patients with NM in head and neck and developed a relatively accurate model to predict the survival probability of them, which could contribute to the tumor assessment and clinical decision-making.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3611-3619, 2024.

Associations Between Cutaneous Melanoma Traits and the Likelihood of Metastasis

Objective This study aims to analyze melanoma characteristics and their correlation with metastasis in 604 patients diagnosed at the Hospital of Lithuanian University of Health Sciences (2018-2023). Materials and methods This retrospective study used coded data from the HLUHS Skin and Venereal Diseases Department database. Data was analyzed using IBM SPSS Statistics; significance was set at p < 0.05. Results Nodal metastases were more prevalent in T4 (43.3%) and T3 (29.7%) tumours compared to other thickness groups (p<0.001). Distant metastases increased with tumour thickness (3.0% in T1 to 21.1% in T4) (p<0.001). Ulceration correlated significantly with nodal (32.3% vs. 14.1%) and distant (16.6% vs. 5.7%) metastases (p<0.001). Males exhibit higher rates of advanced stages, nodal and distant metastases, larger tumours, and torso localization; females show higher rates of superficial spreading melanoma and extremity localization. Conclusions In Lithuanian cases, T1 melanomas prevailed, but T4 thickness was notably frequent, suggesting potential early detection issues. Tumour thickness correlated with nodal (21.2%) and distant metastases (9.9%), highlighting its predictive significance. Ulceration emerged as a prognostic indicator for distant metastases, with males showing thicker tumours and higher metastasis rates, stressing targeted interventions.

Nomogram Predicts Prognostic Factors for Head and Neck Cutaneous Melanoma: A Population-Based Analysis

BACKGROUND

The head and neck cutaneous melanoma (HNCM) accounts for 20% of newly diagnosed melanoma. Research on prognostic models for their survival yet remains largely unexplored. This study employed a nomogram approach to develop and validate a predictive model for both overall survival (OS) and disease-specific survival (DSS) in patients with HNCM.

METHODS

This study analyzed the HNCM patients diagnosed between 2004 and 2014 from Surveillance, Epidemiology, and End Results database. To identify independent prognostic factors for HNCM, we integrated results from univariate Cox regression analysis, random survival forests, and LASSO regression with cross-validation. A nomogram was designed and validated based on the identified characteristics to predict the 3-, 5-, and 8-year OS and DSS of patients with HNCM.

RESULTS

Age, Stage, Ulceration, Thickness, Chemotherapy, lymph node metastasis, and Radiation were identified as independent prognostic factors. The nomogram achieved a satisfactory performance with C-indices of 0.824(DSS) and 0.757(OS) in the training cohort and 0.827(DSS) and 0.749(OS) in the validation cohort, respectively. The area under the curves for the OS at 3, 5, and 8 years were 0.789, 0.788, and 0.794 for the training cohort, and 0.778, 0.776, and 0.795 for the validation cohort, respectively. For DSS, the area under the curves at 3, 5, and 8 years were 0.859, 0.842, and 0.828 in the training cohort, and 0.864, 0.844, and 0.834 in the validation cohort, respectively. The calibration curve showed that there was a strong correlation between the observed outcomes and the predicted survival probability.

CONCLUSIONS

This study established and validated predictive nomograms for HNCM patients with robust predictive performance.

Risk prediction and treatment assessment in glioma patients using SEER database: a prospective observational study

OBJECTIVES

To use a nomogram to predict the risk of mortality and estimate the impact of current treatment on the prognosis of glioma patients.

METHODS

A total of 3798 cases were obtained from the Surveillance Epidemiology and End Results database according to the selection criteria. A nomogram was built on the independent clinical factors screened by the variance inflation factor, univariate analyses and a multivariate Cox regression model. Then, categorising the overall population into high-risk, medium-risk and low-risk groups using nomogram-derived risk scores, to study the impact of treatment on different subgroups' survival outcomes. Furthermore, based on the postmatch cohorts, the influences of treatment on survival outcomes were assessed by the log-rank test.

RESULT

Age, race, stage of disease, histological type, histological grade, surgery, radiotherapy and chemotherapy were identified as the independent prognostic factors. A nomogram with good discrimination and consistency was built. Generally, the patients who underwent surgery, radiotherapy and chemotherapy were more likely to achieve better prognosis than those who did not, except for those who received radiotherapy in the low-risk cohort and those who underwent surgery in the high-risk cohort. Furthermore, the isocitrate dehydrogenase 1/2 (IDH1/2) wild-type patients with surgery, radiotherapy or chemotherapy tended to have higher survival probabilities, while some inconsistent results were observed in the IDH mutant-type cohort.

CONCLUSION

Surgery, radiotherapy and chemotherapy improved the prognosis, while appropriate selection of topical treatment for the low-risk or high-risk patients deserves further consideration. IDH status gene might be a reliable indicator of therapeutic effectiveness.

Uncovering the complex relationship between balding, testosterone and skin cancers in men

Male-pattern baldness (MPB) is related to dysregulation of androgens such as testosterone. A previously observed relationship between MPB and skin cancer may be due to greater exposure to ultraviolet radiation or indicate a role for androgenic pathways in the pathogenesis of skin cancers. We dissected this relationship via Mendelian randomization (MR) analyses, using genetic data from recent male-only meta-analyses of cutaneous melanoma (12,232 cases; 20,566 controls) and keratinocyte cancers (KCs) (up to 17,512 cases; >100,000 controls), followed by stratified MR analysis by body-sites. We found strong associations between MPB and the risk of KC, but not with androgens, and multivariable models revealed that this relationship was heavily confounded by MPB single nucleotide polymorphisms involved in pigmentation pathways. Site-stratified MR analyses revealed strong associations between MPB with head and neck squamous cell carcinoma and melanoma, suggesting that sun exposure on the scalp, rather than androgens, is the main driver. Men with less hair covering likely explains, at least in part, the higher incidence of melanoma in men residing in countries with high ambient UV.

Die Prognose des Melanoms im Kopf-Hals-Bereich im Stadium II hängt vom histologischen Subtyp ab

Hintergrund und Ziele

Die Melanom‐Leitlinie basiert hauptsächlich auf dem AJCC‐Stadium. Hierbei wird nicht zwischen den histologischen Subtypen wie dem superfiziell spreitenden Melanom (SSM), dem Lentigo‐maligna‐Melanom (LMM) oder dem nodulären malignen Melanom (NM) unterschieden. Ziel der Studie war es zu untersuchen, ob sich Patienten mit LMM im klinischen Verlauf von Patienten mit SSM/NM unterscheiden. Dies ist aktuell besonders wichtig, da die adjuvante Anti‐PD‐1‐Therapie für Melanome im Stadium IIB und IIC zugelassen wurde.

Patienten und Methodik

Die Daten wurden aus dem Zentralregister „malignes Melanom“ entnommen. Es wurden nur Patienten mit LMM, SSM oder NM des Kopf‐Hals‐Bereichs und Primärdiagnose zwischen dem 01.01.2000 und dem 31.12.2019 eingeschlossen. Das progressionsfreie Überleben (PFÜ), das melanomspezifische Überleben (MSÜ) und das Metastasierungsmuster wurden für die Gruppe der LMM im Vergleich zur Gruppe der SSM/NM analysiert.

Ergebnisse

Die LMM‐Kohorte (n = 902) hatte ein signifikant besseres MSÜ als die SSM/NM‐Kohorte (n = 604). Beim PFÜ gab es keinen Unterschied. Das 5‐Jahres‐MSÜ der LMM‐Kohorte im Stadium II betrug 88,5 % (95 % KI 81,4–95,6), im Vergleich dazu das der SSM/NM‐Kohorte im Stadium II 79,7 % (95 % KI 72,8–86,6).

Schlussfolgerung

Es scheint nicht angebracht zu sein, eine adjuvante Therapie bei LMM‐Patienten im Stadium II im gleichen Umfang durchzuführen, wie bei Patienten mit SSM/NM.

Prognosis in stage II melanoma of the head and neck depends on the histological subtype

BACKGROUND AND OBJECTIVES

The melanoma guideline is mainly based on the AJCC stage. There is no difference according to histological subtypes such as superficial spreading melanoma (SSM), lentigo maligna melanoma (LMM) or nodular malignant melanoma (NM). We aimed to evaluate whether patients with LMM have a different clinical course from patients with SSM/NM. This is particularly important as adjuvant anti-PD-1 therapy is approved for stage IIB and IIC melanoma.

PATIENTS AND METHODS

Data were extracted from the Central Registry of Malignant Melanoma. Only patients with LMM, SSM, and NM of the head and neck with primary diagnosis between 01/01/2000 and 12/31/2019 were included. Progression-free survival (PFS), melanoma-specific survival (MSS), and pattern of metastases were analyzed for the LMM group compared to SSM/NM.

RESULTS

The LMM cohort (n = 902) had significantly better MSS than the SSM/NM cohort (n = 604). There was no difference in PFS. The 5-year MSS of the stage II LMM cohort was 88.5% (95% CI 81.4-95.6) compared to 79.7% (95% CI 72.8-86.6) in the stage II SSM/NM cohort.

CONCLUSION

It does not appear appropriate to use adjuvant therapy in stage II LMM patients to the same extent as in patients with SSM/NM.

The Impact of Clinical and Histopathological Factors on Disease Progression and Survival in Thick Cutaneous Melanomas

Thick cutaneous melanomas (Breslow depth > 4 mm) are locally advanced tumors, generally associated with poor prognosis. Nevertheless, these tumors sometimes display unpredictable behavior. This study aims to analyze clinical and histopathological features that can influence the prognosis of thick melanomas. This is a retrospective study on 94 thick primary cutaneous melanomas diagnosed between 2012 and 2018 that were followed-up for at least five years to assess disease progression and survival. We evaluated the age, gender, tumor location, histological subtype, Breslow depth, Clark level, resection margins, mitotic index, the presence/absence of ulceration, necrosis, regression, microsatellites, neurotropism, lymphovascular invasion, and the pattern of tumor-infiltrating lymphocytes, and their association with disease progression and survival. By conducting univariate analysis, we found that progression-free survival (PFS) was significantly associated with female gender, the superficial spreading melanoma (SSM) subtype, mitotic index, necrosis, microsatellites, and perineural invasion. Overall survival (OS) was significantly associated with female gender, Breslow depth, SSM subtype, necrosis, microsatellites, and perineural invasion. Through multivariate Cox proportional hazards regression, we found that the only factors associated with PFS were Breslow depth, necrosis, microsatellites, and perineural invasion, while the factors associated with OS were Breslow depth, necrosis, microsatellites, and perineural invasion. Certain histopathological features such as Breslow depth, necrosis, microsatellites, and perineural invasion could explain differences in disease evolution. This is one of the first studies to demonstrate an association between necrosis and perineural invasion and outcomes in patients with thick melanomas. By identifying high-risk patients, personalized therapy can be provided for improved prognosis.

Development and Implementation of a Web-Based International Registry Dedicated to Atypical Pigmented Skin Lesions of the Face: Teledermatologic Investigation on Epidemiology and Risk Factors

Background: Atypical pigmented facial lesions (aPFLs) often display clinical and dermoscopic equivocal and/or overlapping features, thus causing a challenging and delayed diagnosis and/or inappropriate excisions. No specific registry dedicated to aPFL paired with clinical data is available to date. Methods: The dataset is hosted on a specifically designed web platform. Each complete case was composed of the following data: (1) one dermoscopic picture; (2) one clinical picture; (3) two lesion data, that is, maximum diameter and facial location (e.g., orbital area/forehead/nose/cheek/chin/mouth); (4) patient's demographics: family history of melanoma, history of sunburns in childhood, phototype, pheomelanine, eyes/hair color, multiple nevi/dysplastic nevi on the body; and (5) acquisition device (videodermatoscope/camera-based/smartphone-based system). Results: A total of 11 dermatologic centers contributed to a final teledermoscopy database of 1,197 aPFL with a distribution of 353 lentigo maligna (LM), 146 lentigo maligna melanoma (LMM), 231 pigmented actinic keratoses, 266 solar lentigo, 125 atypical nevi, 48 seborrheic keratosis, and 28 seborrheic-lichenoid keratoses. The cheek site was involved in half of aPFL cases (50%). Compared with those with the other aPFL cases, patients with LM/LMM were predominantly men, older (69.32 ± 12.9 years on average vs. 62.69 ± 14.51), exhibited larger lesions (11.88 ± 7.74 mm average maximum diameter vs. 9.33 ± 6.46 mm), and reported a positive history of sunburn in childhood. Conclusions: The iDScore facial dataset currently represents a precious source of data suitable for the design of diagnostic support tools based on risk scoring classifiers to help dermatologists in recognizing LM/LMM among challenging aPFL in clinical practice.

Anatomic Region of Cutaneous Melanoma Impacts Survival and Clinical Outcomes: A Population-Based Analysis

PURPOSE

The objective was to determine the effects of the anatomic site of a cutaneous melanoma on the survival outcomes of diagnosed individuals.

METHODS

We conducted a cross-sectional study using data from the Surveillance, Epidemiology, and End Results Program (SEER) Database from 2004-2014 and included 178,892 cases of individuals diagnosed with cutaneous melanoma. Overall survival (OS) for each anatomic site as well as associated demographics, primary site, stage, and pathologic prognostic factors (Breslow's depth of invasion (DOI), level of mitoses, and ulceration), were analyzed.

RESULTS

Lower extremity melanoma (LEM) was the most likely to have locoregional nodal spread, yet head and neck melanoma (HNM) was the most likely to present at the most advanced stage of disease (IV). Independent of other factors, HNM was associated with the greatest risk of death (HR 1.90 [95% CI, 1.85-1.96]) compared to other sites, and males experienced worse overall survival (OS) (HR 1.74 [95% CI, 1.70-1.78]) compared to females. The last and greatest risk of death is associated with LEM and HNM, respectively.

CONCLUSION

Given these survival differences, consideration should be given to incorporating the primary site of melanoma into staging to ensure treatment is efficacious as possible.

Gradient differences of immunotherapy efficacy in metastatic melanoma related to sunlight exposure pattern: A population-based study

Background

Immune checkpoint inhibitors (ICIs) have revolutionized metastatic melanoma (MM) treatment in just a few years. Ultraviolet (UV) in sunlight is the most significant environmental cause of melanoma, which is considered to be the main reason for tumor mutation burden (TMB) increase in melanoma. High TMB usually predicts that PD-1 inhibitors are effective. The sunlight exposure pattern of MM might be a clinical feature that matches TMB. The relationship between sunlight exposure patterns and immunotherapy response in MM is unclear. This study aims to investigate the correlation between sunlight exposure patterns and immunotherapy response in MM and establish nomograms that predict 3- and 5-year overall survival (OS) rate.

Methods

We searched the Surveillance, Epidemiology, and End Results (SEER) database and enrolled MM cases from 2005-2016. According to the advent of ICIs in 2011, the era was divided into the non-ICIs era (2005-2010) and the ICIs era (2011-2016). Patients were divided into three cohorts according to the primary site sunlight exposure patterns: head and neck in the first cohort, trunk arms and legs in the second cohort, and acral sites in the third cohort. We compared survival differences for each cohort between the two eras, performed stratified analysis, established nomograms for predicting 3- and 5-year OS rate, and performed internal validation.

Results

Comparing the survival difference between the ICIs and non-ICIs era, head and neck melanoma showed the greatest improvement in survival, with 3- and 5-year OS rate increasing by 10.2% and 9.1%, respectively (P=0.00011). In trunk arms and legs melanoma, the 3- and 5-year OS rate increased by 4.6% and 3.9%, respectively (P<0.0001). There is no improvement in survival in acral melanoma (AM) between the two eras (P=0.78). The receiver operating characteristic (ROC) curve, area under the ROC curve (AUC) and calibration graphs show good discrimination and accuracy of nomograms. Decision curve analysis (DCA) suggests good clinical utility of nomograms.

Conclusions

Based on the classification of sunlight exposure patterns, there is a gradient difference in immunotherapy efficacy for MM. The degree of sunlight exposure is positively correlated with immunotherapy response. The nomograms are sufficiently accurate to predict 3- and 5-year OS rate for MM, allowing for individualized clinical decisions for future clinical work.

Risk factors for lymphatic and hematogenous metastasis after diagnosis of cutaneous Melanoma in Taiwan

BACKGROUND

Risk factors of lymphatic and hematogenous metastasis in cutaneous melanoma remained unclear in Asian population. This study aimed to identify clinical and histopathological factors to predict metastatic pathways in cutaneous melanoma in Taiwan.

METHODS

A total of 247 patients diagnosed as stage I and II melanoma, followed at National Taiwan University Hospital were included in this retrospective study from 1980 to 2020. Kaplan-Meier curves and Cox proportional hazards regression were utilized to identify risk factors.

RESULTS

During a median follow-up of 143 months, 48 (19.4%) and 62 (25.1%) patients developed lymphatic and hematogenous metastasis respectively. In the univariate analysis, age> 70 years, greater Breslow thickness, ulceration, neurotropism, and NRAS mutation were significant risk factors for lymphatic metastasis in all subtypes of melanoma. Age >70 years, head and neck location, thickness, ulceration, higher mitotic rate, neurotropism, and NRAS mutation were significant predictors of hematogenous metastasis in all subtypes. In the multivariate analysis, greater thickness (HR for 2.0-4.0 mm, 4.5; p = .009 and HR for >4.0 mm, 5.7; p = .003) retained its significance as an independent risk factor for lymphatic metastasis in all subtypes of melanoma. Thickness (HR for >4.0 mm, 5.7; p < .001) and ulceration (HR, 2.5; p = .001) were independent risk factors for hematogenous metastasis.

CONCLUSION

Risk factors of metastasis not only differ between lymphatic and hematogenous pathways, but also differ between ethnics and melanoma subtypes. Better understanding the behavior of cutaneous melanoma may help guide further treatments and follow-up plans.

A cohort analysis of surgically treated primary head and neck lentigo maligna (melanoma): Prognostic value of melanoma subtype and new insights in the clinical value of guideline adherence

BACKGROUND

Knowledge about lentigo maligna (melanoma) (LM/LMM) and its associated prognostic clinicopathological characteristics are limited compared to that of non-LM/LMM subtypes. The current study aimed to determine the clinical relevance of the LM/LMM subtype and its influence on recurrence and survival outcomes.

METHODS

All consecutive cases of primary cutaneous head and neck LM/LMM treated by wide local excision over a ten-year period were retrospectively reviewed and compared to non-LM/LMM. Clinical outcome and prognostic factors were assessed by cumulative incidence and competing risk analyses.

RESULTS

A total of 345 patients were identified. Specific clinicopathological characteristics such as lower median Breslow thickness (1.6 mm versus 2.1 mm; P = 0.013), association with diagnostic sampling errors (17.3% versus 5.2%; P = 0.01), and increased risk of local recurrences due to incomplete resection (18.7% versus 2.3%; P < 0.001), were significantly associated with LM/LMM. Guideline adherence was similar between the two study groups. The positive nodal status at baseline for LMM was low compared to non-LM/LMM (4.2% vs 17.9%; P = 0.037). The LMM subtype, facial localization, and reduced surgical margins (i.e., guideline non-adherence) were not shown to be independent prognostic factors for disease-free, melanoma-specific, or overall survival after correction for competing risks such as patient age and Breslow thickness.

CONCLUSIONS

The LMM subtype was not shown to be prognostically different from non-LM/LMM when corrected for other variables of influence such as patient age and Breslow thickness. Reduced resection margins did not seem to affect disease-free, and melanoma-specific survival and warrant LM/LMM-specific guidelines. Further research is needed to evaluate the value of SLNB in LMM patients.

Development of an Early Warning Model for Predicting the Death Risk of Coronavirus Disease 2019 Based on Data Immediately Available on Admission

Introduction: COVID-19 has overloaded worldwide medical facilities, leaving some potentially high-risk patients trapped in outpatient clinics without sufficient treatment. However, there is still a lack of a simple and effective tool to identify these patients early.

Methods: A retrospective cohort study was conducted to develop an early warning model for predicting the death risk of COVID-19. Seventy-five percent of the cases were used to construct the prediction model, and the remaining 25% were used to verify the prediction model based on data immediately available on admission.

Results: From March 1, 2020, to April 16, 2020, a total of 4,711 COVID-19 patients were included in our study. The average age was 63.37 ± 16.70 years, of which 1,148 (24.37%) died. Finally, age, SpO2, body temperature (T), and mean arterial pressure (MAP) were selected for constructing the model by univariate analysis, multivariate analysis, and a review of the literature. We used five common methods for constructing the model and finally found that the full model had the best specificity and higher accuracy. The area under the ROC curve (AUC), specificity, sensitivity, and accuracy of full model in train cohort were, respectively, 0.798 (0.779, 0.816), 0.804, 0.656, and 0.768, and in the validation cohort were, respectively, 0.783 (0.751, 0.815), 0.800, 0.616, and 0.755. Visualization tools of the prediction model included a nomogram and an online dynamic nomogram (https://wanghai.shinyapps.io/dynnomapp/).

Conclusion: We developed a prediction model that might aid in the early identification of COVID-19 patients with a high probability of mortality on admission. However, further research is required to determine whether this tool can be applied for outpatient or home-based COVID-19 patients.

Characteristics of 637 melanomas documented by 27 general practitioners on the Skin Cancer Audit Research Database

BACKGROUND AND OBJECTIVE

Most melanomas (including melanomas in situ), in Australasia, are treated by general practitioners (GPs). Previously undescribed, the characteristics of a series of melanomas treated by multiple GPs are examined.

PATIENTS AND METHODS

Six hundred and thirty-seven melanomas treated by 27 Australasian GPs during 2013 and documented on the Skin Cancer Audit Research Database (SCARD) were analysed by anatomical site, subtype, Breslow thickness, diameter, associated naevi and linked adverse outcomes.

RESULTS

Most melanomas (59.7%) were on males, mean age at diagnosis being 62.7 years (range 18-96). Most (65.0%) were in situ, with a high incidence of lentiginous melanoma (LM) (38.8%) and 32% were naevus associated. Most LM (86.4%) were in situ, compared to 55% of superficial spreading melanoma (SSM) (P < 0.0001). There was male predominance on the head, neck and trunk and female predominance on extremities. There was no significant association between Breslow thickness and diameter, with small melanomas as likely to be thick as large melanomas, and melanomas ≤3 mm diameter, on average, more likely to be invasive than larger melanomas. There was a positive correlation between age and both melanoma diameter and Breslow thickness. Seven cases progressed to melanoma-specific death: Five nodular melanoma (NM) and two SSM, one of which was thin (Breslow thickness 0.5 mm).

CONCLUSIONS

A large series of melanomas treated by Australasian GPs were predominantly in situ, with a high proportion of LM subtype. With implications for GP training, NM linked to death was over-represented and there was a novel finding that older patients had larger diameter melanomas.