The Effect of Neoadjuvant Systemic Therapy on Surgical Outcomes After Lymph Node Dissections for Stage III Melanoma; An Australian Cohort.

BACKGROUND: Neoadjuvant systemic therapy (NAST) for patients with stage III melanoma achieves high major pathologic response rates and high recurrence-free survival rates. This study aimed to determine how NAST with targeted therapies (TTs) and immune checkpoint inhibitors (ICIs) influences surgical outcomes after lymph node dissection in terms of complications, morbidity, and textbook outcomes. METHODS: Patients who underwent a lymph node dissection after either NAST in a clinical trial or upfront surgery for stage III melanoma between 2014 and 2022 were identified from an institutional research database. RESULTS: The study included 89 NAST-treated patients and 79 upfront surgery-treated patients. The rate of postoperative complications did not differ between the NAST- and upfront surgery-treated patients (55% vs. 51%; p = 0.643), and steroid treatment for drug toxicity did not influence the complication rate (odds ratio [OR], 1.1; 95% confidence interval [CI], 0.4-3; p = 0.826). No significant differences in postoperative morbidity were observed in terms of seroma (23% vs. 11%; p = 0.570) or lymphedema (36% vs. 51%; p = 0.550). The rate of achieving a textbook outcome was comparable for the two groups (61% vs. 57%; p = 0.641). CONCLUSIONS: The surgical outcomes after lymph node dissections were comparable between the patients who received NAST and those who had upfront surgery, indicating that surgery can be safely performed after NAST with TT or ICI for stage III melanoma.

Impact of an Online Risk Calculator for Sentinel Node Positivity on Management of Patients with T1 and T2 Melanomas.

BACKGROUND: Predicting which patients with American Joint Committee on Cancer (AJCC) T1-T2 melanomas will have a positive sentinel lymph node (SLN) is challenging. Melanoma Institute Australia (MIA) developed an internationally validated SLN metastatic risk calculator. This study evaluated the nomogram's impact on T1-T2 melanoma patient management at MIA. METHODS: SLN biopsy (SLNB) rates were compared for the pre- and post-nomogram periods of 1 July 2018-30 June 2019 and 1 August 2020-31 July 2021, respectively. RESULTS: Overall, 850 patients were identified (pre-nomogram, 383; post-nomogram, 467). SLNB was performed in 29.0% of patients in the pre-nomogram group and 34.5% in the post-nomogram group (p = 0.091). The overall positivity rate was 16.2% in the pre-nomogram group and 14.9% in the post-nomogram group (p = 0.223). SLNB was performed less frequently in T1a melanoma patients in the pre-nomogram group (1.1%, n = 2/177) than in the post-nomogram group (8.6%, n = 17/198) [p ≤ 0.001]. This increase was particularly for melanomas with a risk score ≥ 5%, with an SLN positivity rate of 11.8% in the post-nomogram group (p = 0.004) compared with zero. For T1b melanomas with a risk score of > 10%, the SLNB rate was 40.0% (8/20) pre-nomogram and 75.0% (12/16) post-nomogram (p = 0.049). CONCLUSIONS: In this specialized center, the SLN risk calculator appears to influence practice for melanomas previously considered low risk for metastasis, with increased use of SLNB for T1a and higher-risk T1b melanomas. Further evaluation is required across broader practice settings. Melanoma management guidelines could be updated to incorporate the availability of nomograms to better select patients for SLNB than previous criteria.

Role of Concurrent Ultrasound Surveillance of Sentinel Node-Positive Node Fields in Melanoma Patients Having Routine Cross-Sectional Imaging.

PURPOSE: In sentinel node-positive (SN+ve) melanoma patients, active surveillance with regular ultrasound examination of the node field has become standard, rather than completion lymph node dissection (CLND). A proportion of these patients now receive adjuvant systemic therapy and have routine cross-sectional imaging (computed tomography [CT] or positron emission tomography [PET]/CT). The role of concurrent ultrasound (US) surveillance in these patients is unclear. The purpose of our study was to describe the modality of detection of nodal recurrence in SN+ve node fields. METHODS: SN+ve melanoma patients who did not undergo CLND treated at a single institution from January 1, 2016 to December 31, 2020 were included. RESULTS: A total of 225 SN+ve patients with a median follow-up of 23 months were included. Of these, 119 (53%) received adjuvant systemic therapy. Eighty (36%) developed a recurrence at any site; 24 (11%) recurred first in the SN+ve field, of which 12 (5%) were confirmed node field recurrence only at 2 months follow-up. The nodal recurrences were first detected by ultrasound in seven (3%), CT in seven (3%), and PET/CT in seven (3%) patients. All nodal recurrences evident on US were also evident on PET/CT and vice versa. CONCLUSIONS: The high rate of recurrences outside the node field and the identification of all US-detected nodal recurrences on concurrent cross-sectional imaging modalities suggest that routine concurrent ultrasound surveillance of the node-positive field may be unnecessary for SN+ve melanoma patients having routine cross-sectional imaging.

Adjuvant radiotherapy after salvage surgery for melanoma recurrence in a node field following a previous lymph node dissection.

BACKGROUND AND OBJECTIVES: Adjuvant radiotherapy (RT) can be given to melanoma patients following salvage surgery for node field recurrence after a previous regional node dissection, but the value of this treatment strategy is poorly documented. This study evaluated long-term node field control and survival of patients treated in this way in an era before effective adjuvant systemic therapy became available. METHODS: Data for 76 patients treated between 1990 and 2011 were extracted from an institutional database. Baseline patient characteristics, treatment details and oncological outcomes were analysed. RESULTS: Adjuvant RT with conventional fractionation (median dose 48 Gy in 20 fractions) was given to 43 patients (57%) and hypofractionated RT (median dose 33 Gy in 6 fractions) to 33 patients (43%). The 5-year node field control rate was 70%, 5-year recurrence-free survival 17%, 5-year melanoma-specific survival 26% and 5-year overall survival 25%. CONCLUSIONS: Salvage surgery with adjuvant RT achieved node field control in 70% of melanoma patients with node field recurrence following a prior node dissection. However, disease progression at distant sites was common and survival outcomes were poor. Prospective data will be required to assess outcomes for contemporary combinations of surgery, adjuvant RT and systemic therapy.

Whole-genome landscapes of major melanoma subtypes.

Melanoma of the skin is a common cancer only in Europeans, whereas it arises in internal body surfaces (mucosal sites) and on the hands and feet (acral sites) in people throughout the world. Here we report analysis of whole-genome sequences from cutaneous, acral and mucosal subtypes of melanoma. The heavily mutated landscape of coding and non-coding mutations in cutaneous melanoma resolved novel signatures of mutagenesis attributable to ultraviolet radiation. However, acral and mucosal melanomas were dominated by structural changes and mutation signatures of unknown aetiology, not previously identified in melanoma. The number of genes affected by recurrent mutations disrupting non-coding sequences was similar to that affected by recurrent mutations to coding sequences. Significantly mutated genes included BRAF, CDKN2A, NRAS and TP53 in cutaneous melanoma, BRAF, NRAS and NF1 in acral melanoma and SF3B1 in mucosal melanoma. Mutations affecting the TERT promoter were the most frequent of all; however, neither they nor ATRX mutations, which correlate with alternative telomere lengthening, were associated with greater telomere length. Most melanomas had potentially actionable mutations, most in components of the mitogen-activated protein kinase and phosphoinositol kinase pathways. The whole-genome mutation landscape of melanoma reveals diverse carcinogenic processes across its subtypes, some unrelated to sun exposure, and extends potential involvement of the non-coding genome in its pathogenesis.

Multiplex melanoma families are enriched for polygenic risk.

Cancers, including cutaneous melanoma, can cluster in families. In addition to environmental etiological factors such as ultraviolet radiation, cutaneous melanoma has a strong genetic component. Genetic risks for cutaneous melanoma range from rare, high-penetrance mutations to common, low-penetrance variants. Known high-penetrance mutations account for only about half of all densely affected cutaneous melanoma families, and the causes of familial clustering in the remainder are unknown. We hypothesize that some clustering is due to the cumulative effect of a large number of variants of individually small effect. Common, low-penetrance genetic risk variants can be combined into polygenic risk scores. We used a polygenic risk score for cutaneous melanoma to compare families without known high-penetrance mutations with unrelated melanoma cases and melanoma-free controls. Family members had significantly higher mean polygenic load for cutaneous melanoma than unrelated cases or melanoma-free healthy controls (Bonferroni-corrected t-test P = 1.5 × 10-5 and 6.3 × 10-45, respectively). Whole genome sequencing of germline DNA from 51 members of 21 families with low polygenic risk for melanoma identified a CDKN2A p.G101W mutation in a single family but no other candidate high-penetrance melanoma susceptibility genes. This work provides further evidence that melanoma, like many other common complex disorders, can arise from the joint action of multiple predisposing factors, including rare high-penetrance mutations, as well as via a combination of large numbers of alleles of small effect.

Clinicopathological Characteristics Predicting Further Recurrence and Survival Following Resection of In-Transit Melanoma Metastases.

BACKGROUND: In-transit metastases (ITMs) affect approximately 4% of patients with cutaneous melanoma. This study sought to identify clinical and pathological characteristics that predict further recurrence and survival following resection of ITMs. PATIENTS AND METHODS: Patients (n = 573) who underwent surgical resection of their first presentation of ITM following previous surgical treatment of an American Joint Committee on Cancer (AJCC) stage I-II melanoma between 1969 and 2017 were identified from an institutional database. Clinicopathological predictors of patterns of recurrence and survival following ITM resection were sought. RESULTS: The median time of ITM development was 2.4 years after primary melanoma resection. ITMs were most frequently located on the lower limb (51.0%). The most common melanoma subtype associated with ITM development was nodular melanoma (44.1%). After surgical resection of a first ITM, 65.4% of patients experienced recurrent disease. Most recurrences were locoregional (44.7%), with distant metastasis occurring in 23.9% of patients. Lower limb ITMs were more frequently associated with subsequent ITMs [odds ratio (OR) 2.41, p = 0.0002], and the lowest risk of distant metastasis (p < 0.0001) compared with other primary sites. Primary melanomas and ITM on head and neck, as well as the presence of ulceration, were associated with worse survival. CONCLUSIONS: Recurrence after surgical resection of a first ITM was common. Patterns of recurrence differed according to anatomical site; further ITM recurrences were more likely for lower limb ITMs, which were also associated with longer distant recurrence-free survival. Distant metastasis was more common for ITM on the head and neck, with worse survival.

Histological regression in melanoma: impact on sentinel lymph node status and survival.

Regression in melanoma is an immunological phenomenon that results in partial or complete replacement of the tumor with variably vascular fibrous tissue, often accompanied by pigment-laden macrophages and chronic inflammation. In some cases, tumor-infiltrating lymphocytes (TILs) may represent the earliest phase of this process. The prognostic significance of regression has long been a matter of debate, with inconsistent findings reported in the literature to date. This study sought to determine whether regression in primary cutaneous melanomas predicted sentinel lymph node (SLN) status and survival outcomes in a large cohort of patients managed at a single centre. Clinical and pathological parameters for 8,693 consecutive cases were retrieved. Associations between regression and SLN status, overall survival (OS), melanoma-specific survival (MSS) and recurrence-free survival (RFS) were investigated using logistic and Cox regression. Histological evidence of regression was present in 1958 cases (22.5%). Regression was significantly associated with lower Breslow thickness, lower mitotic rate, and absence of ulceration (p < 0.0001). Multivariable analysis showed that regression in combination with TILs independently predicted a negative SLN biopsy (OR 0.33; 95% C.I. 0.20-0.52; p < 0.0001). Patients whose tumors showed both regression and TILs had the highest 10-year OS (65%, 95% C.I. 59-71%), MSS (85%, 95% C.I. 81-89%), and RFS (60%, 95% C.I. 54-66%). On multivariable analyses, the concurrent presence of regression and TILs independently predicted the lowest risk of death from melanoma (HR 0.69; 95% C.I. 0.51-0.94; p = 0.0003) as well as the lowest rate of disease recurrence (HR 0.71; 95% C.I. 0.58-0.85; p < 0.0001). However, in contrast, in the subgroup analysis of Stage III patients, the presence of regression predicted the lowest OS and RFS, with MSS showing a similar trend. Overall, these findings indicate a prognostically favorable role of regression in primary cutaneous melanoma. However, in Stage III melanoma patients, regression may be a marker of more aggressive disease.

Survival Outcomes of Salvage Metastasectomy After Failure of Modern-Era Systemic Therapy for Melanoma.

BACKGROUND: Metastasectomy for selected patients with melanoma was associated with improved survival in the era before effective systemic therapy. Emerging evidence shows that these benefits persist even in this era of BRAF-targeted therapy and immune checkpoint inhibitor immunotherapy. This study aimed to evaluate the outcomes of salvage metastasectomy after failure of systemic therapy. METHODS: Stage 3 or 4 melanoma patients with extracranial disease progression after at least 4 weeks of systemic treatment between 2009 and 2020 were identified and categorized as resected to no evidence of disease (NED), non-progressive residual disease (NPRD), or progressive residual disease (PRD). Systemic therapy was stratified into BRAF-targeted therapy, immune checkpoint inhibitor immunotherapy, or both. The end points of overall survival (OS), progression-free survival (PFS), and locoregional disease control (LRC) were assessed using Kaplan-Meier curves. Uni- and multivariable Cox regression procedures were used to examine factors associated with OS, PFS and LRC. RESULTS: The study enrolled 190 patients. Among all the patients, the 5-year OS from metastatectomy was 52%, the 3-year PFS was 21%, and the 5-year LRC was 61%. After resection to NED, NPRD, and PRD, the 5-year OS values were 69%, 62% and 8%, respectively. Fewer lines of preoperative therapy, use of preoperative immunotherapy, and resection to NED were predictors of improved OS. After resection to NED, NPRD, and PRD, the 3-year PFS values were 23%, 24% and 10%, and the 5-year LRC values were 61%, 72% and 34%, respectively. CONCLUSIONS: Salvage metastasectomy was associated with durable survival and disease control, particularly after resection to NED, preoperative immunotherapy, and fewer lines of preoperative systemic therapy.

A practical guide on the use of imiquimod cream to treat lentigo maligna.

Lentigo maligna (LM) is a common in situ melanoma subtype arising on chronically sun-damaged skin and mostly affects the head and neck region. Localisation in cosmetically sensitive areas, difficulty to obtain wide resection margins and advanced patient age/comorbidities have encouraged investigation of less invasive therapeutic strategies than surgery in managing complex cases of LM. Radiotherapy and imiquimod have emerged as alternative treatment options in this context. The treatment of LM with imiquimod cream can be challenging due to the nature of the disease including its often large size, variegated appearance, involvement of adnexal structures, poorly defined peripheral edge and frequent localisation close to sensitive structures such as the eyes and lips, and elderly patients with multiple comorbidities. Prolonged and unpredictable inflammatory reaction and side effects and compliance with a patient-delivered therapy can also be challenging. In the literature to date, studies evaluating the use of imiquimod to treat LM have utilised varying methodologies and provided short follow-up and these limitations have impaired the development of clear guidelines for dosage and management of side effects. Based on our multidisciplinary experience and review of the literature, we propose practical clinical strategies for the use of imiquimod for treating LM, detailing optimal administration procedures in various clinical scenarios and long-term management, with the aim of facilitating optimal patient outcomes.

Reappraisal of the prognostic significance of mitotic rate supports its reincorporation into the melanoma staging system.

BACKGROUND: Mitotic rate is a strong, independent prognostic factor in patients with melanoma. However, incorporating it into the melanoma staging system has proved challenging. METHODS: The prognostic impact of mitotic rate was assessed in a melanoma cohort comprising 5050 patients from 2 geographically distinct populations. Computer-generated cut points for mitotic rate were constructed to determine its impact on melanoma-associated survival using Kaplan-Meier and multivariate regression analyses. The impact of mitotic rate also was assessed in randomly split training and validation sets. RESULTS: Mitotic rate had a nonlinear impact on survival, as evidenced by unequally spaced cut points. An index incorporating these cut points that was constructed from one population produced significantly more accurate predictions of survival in the other population than using the entire scale of mitotic rate. An index constructed from the combined cohort was found to be independently predictive of survival, with an impact comparable to that of ulceration. Optimal high-versus-low cut points for mitotic rate were generated separately for each T category (<2 mitoses/mm2 vs ≥2 mitoses/mm2 for T1 melanoma, <4 mitoses/mm2 vs ≥4 mitoses/mm2 for T2 melanoma, <6 mitoses/mm2 vs ≥6/mitoses/mm2 for T3 melanoma, and <7 mitoses/mm2 vs ≥7 mitoses/mm2 for T4 melanoma). Using Kaplan-Meier analysis, elevated mitotic rate was found to have an impact on survival comparable to that of ulceration within each T category. Application of the index for mitotic rate that was constructed from the training data set demonstrated an independent impact in the validation data set, with a significance similar to that of ulceration. CONCLUSIONS: The results of the current study demonstrated the comparable prognostic impact of mitotic rate and ulceration, providing support for its reincorporation into the T category.

Evidence-Based Clinical Practice Guidelines for the Management of Patients with Lentigo Maligna.

INTRODUCTION: Lentigo maligna (LM) is a subtype of melanoma in situ that usually occurs in sun-damaged skin and is characterised by an atypical proliferation of melanocytes within the basal epidermis. If left untreated, LM can develop into invasive melanoma, termed lentigo maligna melanoma, which shares the same prognosis as other types of invasive melanoma. The incidence rates of LM are steadily increasing worldwide, in parallel with increases in the incidence rates of invasive melanoma, and establishing appropriate guidelines for the management of LM is therefore of great importance. METHODS: A multidisciplinary working party established by Cancer Council Australia has recently produced up-to-date, evidence-based clinical practice guidelines for the management of melanoma and LM. Following selection of the most relevant clinical questions, a comprehensive literature search for relevant studies was conducted, followed by systematic review of these studies. Data were summarised and the evidence was assessed, leading to the development of recommendations. After public consultation and approval by the full guidelines working party, these recommendations were published on the Cancer Council Australia wiki platform (https://wiki.cancer.org.au/australia/Clinical_question:Effective_interventions_to_improve_outcomes_in_lentigo_maligna%3F). Main Recommendations: Surgical removal of LM remains the standard treatment, with 5- to 10-mm clinical margins when possible. While yet to be fully validated, the use of peri-operative reflectance confocal microscopy to assess margins should be considered where available. There is a lack of high-quality evidence to infer the most effective non-surgical treatment. When surgical removal of LM is not possible or refused, radiotherapy is recommended. When both surgery and radiotherapy are not appropriate or refused, topical imiquimod is the recommended treatment. Cryotherapy and laser therapy are not recommended for the treatment of LM.

Neoadjuvant dabrafenib combined with trametinib for resectable, stage IIIB-C, BRAFV600 mutation-positive melanoma (NeoCombi): a single-arm, open-label, single-centre, phase 2 trial.

BACKGROUND: Adjuvant dabrafenib plus trametinib therapy improves relapse-free survival in patients with resected stage III melanoma. We aimed to ascertain the proportion of patients who would have a pathological response and a response according to Response Evaluation Criteria in Solid Tumors (RECIST) after neoadjuvant dabrafenib plus trametinib therapy for resectable clinical stage III melanoma. METHODS: NeoCombi was a single-arm, open-label, single-centre, phase 2 study done at Melanoma Institute Australia (Sydney, NSW, Australia). Eligible patients were adults (aged ≥18 years) with histologically confirmed, resectable, RECIST-measurable, clinical stage IIIB-C (American Joint Committee on Cancer [AJCC] 7th edition), BRAFV600-mutant melanoma, and had an Eastern Cooperative Oncology Group performance status of 1 or lower. Patients received 150 mg dabrafenib orally, twice daily, plus 2 mg trametinib orally, once daily, for 52 weeks (12 weeks of neoadjuvant therapy before complete resection of the pre-therapy tumour bed, and 40 weeks of adjuvant therapy thereafter). CT and PET scans were done at baseline and before resection. The primary outcomes were the proportion of patients achieving a complete pathological response and the proportion of patients achieving a response according to RECIST at week 12, analysed as per protocol. This trial is registered with ClinicalTrials.gov, NCT01972347, and follow-up of patients is ongoing. FINDINGS: Between Aug 20, 2014, and April 19, 2017, 40 patients were screened, of whom 35 eligible patients were enrolled, received neoadjuvant dabrafenib plus trametinib, and underwent resection. At the data cutoff (Sept 24, 2018), median follow-up was 27 months (IQR 21-36). At resection, 30 (86%) patients achieved a RECIST response; 16 (46%; 95% CI 29-63) had a complete response and 14 (40%; 24-58) had a partial response. Five patients (14%; 95% CI 5-30) had stable disease, and no patients progressed. After resection and pathological evaluation, all 35 patients achieved a pathological response, of whom 17 (49%; 95% CI 31-66) patients had a complete pathological response and 18 (51%; 95% CI 34-69) had a non-complete pathological response. Treatment-related serious adverse events occurred in six (17%) of 35 patients and grade 3-4 adverse events occurred in ten (29%) patients. No treatment-related deaths were reported. INTERPRETATION: Neoadjuvant dabrafenib plus trametinib therapy could be considered in the management of RECIST-measurable resectable stage III melanoma as it led to a high proportion of patients achieving a complete response according to RECIST and a high proportion of patients achieving a complete pathological response, with no progression during neoadjuvant therapy. FUNDING: GlaxoSmithKline; Novartis; National Health and Medical Research Council, Australia; and Melanoma Institute Australia.

Whole genome sequencing of melanomas in adolescent and young adults reveals distinct mutation landscapes and the potential role of germline variants in disease susceptibility.

Cutaneous melanoma accounts for at least >10% of all cancers in adolescents and young adults (AYA, 15-30 years of age) in Western countries. To date, little is known about the correlations between germline variants and somatic mutations and mutation signatures in AYA melanoma patients that might explain why they have developed a cancer predominantly affecting those over 65 years of age. We performed genomic analysis of 50 AYA melanoma patients (onset 10-30 years, median 20); 25 underwent whole genome sequencing (WGS) of both tumor and germline DNA, exome data were retrieved from 12 TCGA AYA cases, and targeted DNA sequencing was conducted on 13 cases. The AYA cases were compared with WGS data from 121 adult cutaneous melanomas. Similar to mature adult cutaneous melanomas, AYA melanomas showed a high mutation burden and mutation signatures of ultraviolet radiation (UVR) damage. The frequencies of somatic mutations in BRAF (96%) and PTEN (36%) in the AYA WGS cohort were double the rates observed in adult melanomas (Q < 6.0 × 10-6 and 0.028, respectively). Furthermore, AYA melanomas contained a higher proportion of non-UVR-related mutation signatures than mature adult melanomas as a proportion of total mutation burden (p = 2.0 × 10-4 ). Interestingly, these non-UVR mutation signatures relate to APOBEC or mismatch repair pathways, and germline variants in related genes were observed in some of these cases. We conclude that AYA melanomas harbor some of the same molecular aberrations and mutagenic insults occurring in older adults, but in different proportions. Germline variants that may have conferred disease susceptibility correlated with somatic mutation signatures in a subset of AYA melanomas.

Correlation Between Surgical and Histologic Margins in Melanoma Wide Excision Specimens.

INTRODUCTION: Wide surgical excision is the standard treatment for localized primary cutaneous melanomas, with a narrow histologic margin associated with an increased risk of local recurrence. The correlation between surgical and histologic margins is poorly documented in the literature. METHODS: An audit was performed to (1) document the shrinkage of formalin-fixed specimens, and (2) use a precisely measured surgical margin in vivo to predict the histologic margin. For patients presenting for wide excision of melanomas and other malignant skin tumors, measured surgical margin, in vivo and ex vivo specimen width, and histologic margins after formalin fixation were recorded. The effects of clinicopathologic characteristics, including age, sex, body mass index (BMI), tumor type, anatomic site, and presence of visible tumor in predicting specimen shrinkage and histologic margin were assessed. RESULTS: In total, 252 specimens were evaluated. When compared with measured width in vivo, the formalin-fixed specimens showed a mean shrinkage of 14% (R2 = 0.98), regardless of patient age, sex, BMI, or site of the lesion. The measured surgical margin was not a strong predictor of the histologic margin, with a high degree of variability (R2 = 0.55) not explained by patient factors, tumor subtype, or presence of visible tumor at the time of excision (p > 0.05). CONCLUSIONS: A consistent 14% shrinkage rate of wide excision specimens was found across all patients and excision sites, and we propose a clinically useful 15% correction factor that will account for fixation and shrinkage of cutaneous excision specimens. Excision margins measured by the surgeon were a poor predictor of the histologic margins.

Subungual Melanoma of the Hand.

BACKGROUND: The diagnosis of subungual melanoma (SUM) can be challenging and SUMs generally have a worse prognosis than melanomas arising elsewhere. Due to their rarity, the evidence to guide management is limited. This study sought to identify clinicopathological features predictive of outcome and to provide guidelines for management. METHODS: From a large, single-institution database, 103 patients with in situ (n = 9) or invasive (n = 94) SUMs of the hand treated between 1953 and 2014 were identified and their features analyzed. RESULTS: The most common site of hand SUMs was the thumb (53%). Median tumor thickness was 3.1 mm, and SUMs were commonly of the acral subtype (57%), ulcerated (58%), amelanotic (32%), and had mitoses (73%). Twenty-one patients reported prior trauma to the tumor site. Twenty-two patients were stage III at diagnosis; 7 underwent therapeutic lymph node dissection and 22 underwent elective lymph node dissection (5 positive), while 36 had sentinel node biopsy (SNB), 28% of which were positive. Forty percent of SNB-positive patients had involved non-sentinel nodes (SNs) in their completion lymph node dissection. Five-year melanoma-specific survival (MSS) and disease-free survival (DFS) rates were 70% and 52%, respectively. On multivariate analysis, regional node metastasis and right-hand tumor location were significant predictors of shorter DFS and MSS, whereas mitoses negatively impacted DFS only and increasing Breslow thickness impacted MSS only. CONCLUSIONS: This study confirms that SUMs on the hand usually present at an advanced stage. Distal amputation appears safe for invasive SUMs, and SNB should be considered as these patients have a high risk of both SN and non-SN metastasis.

Neurotropic melanoma: an analysis of the clinicopathological features, management strategies and survival outcomes for 671 patients treated at a tertiary referral center.

Neurotropic cutaneous melanoma is a rare melanoma subtype that invades nerves and is often associated with desmoplastic melanoma. Limited data suggest that it has a greater propensity to recur locally, but it is unknown whether its behavior differs from that of other melanoma subtypes, including desmoplastic melanoma. We investigated clinicopathological predictors of outcome in a cohort of 671 patients with neurotropic melanoma to develop evidence-based management recommendations. Patients with primary neurotropic melanoma diagnosed from 1985 to 2013 were identified from the Melanoma Institute Australia database, along with a control cohort of 718 non-neurotropic melanoma patients. Features predictive of sentinel lymph node status, recurrence, melanoma-specific survival and response to adjuvant radiotherapy were sought. Neither local recurrence (hazard ratio: 1.28 (0.73-2.25) P=0.39) nor melanoma-specific survival (hazard ratio: 0.79 (0.55-1.15) P=0.22) were significantly affected by the presence of neurotropism on multivariate analysis. However, there was a markedly reduced likelihood of sentinel node positivity (hazard ratio: 0.61 (0.41-0.89) P=0.01) in neurotropic melanoma patients. Surgical margins ≥8mm halved the recurrence risk compared with <2 mm margins (hazard ratio: 0.46 (0.31-0.68) P<0.001). Additionally, in neurotropic melanoma patients with <8 mm margins, adjuvant radiotherapy halved the recurrence risk (hazard ratio: 0.48 (0.27-0.87) P=0.02). This, the largest study of neurotropic melanoma reported to date, has demonstrated that the presence of neurotropism does not alter the risk of melanoma recurrence or survival but does reduce the likelihood of sentinel node positivity. For successful treatment of neurotropic melanoma, adequate excision margins are of paramount importance. However, when adequate margins cannot be achieved, adjuvant radiotherapy reduces the risk of recurrence.