The end of wide local excision (WLE) margins for melanoma ?

Reduction in surgical interventions in melanoma

Melanoma surgery has evolved from elective lymph node dissection (ELND) to sentinel lymph node biopsy (SLNB) and wide local excision (WLE) margins have come down from 5 cm to nowadays 1 - 2 cm. Recent studies have illustrated the low frequency of residual tumour cells in WLE specimen, particularly for pT2 or lower tumours, where 97 % of patients cannot benefit from WLE. Moreover, a cohort of completely excised primary melanomas did not seem to have inferior clinical outcomes to those who did undergo WLE. Biomarkers, such as clinicopathological gene expression profilers (CP-GEP), can stratify high- and low-risk disease and make therapy decisions, in particular in clinical stage I/II melanoma and make sentinel lymph node biopsy (SLNB) largely redundant. Also SLNB needs to be reconsidered due to the lack of a clear overall survival benefit for adjuvant therapy in stage III. Moreover SLNB is redundant in stage IIB/C for decision making on adjuvant anti-PD1 therapy. Moreover the superiority of neo-adjuvant to salvage patients with macroscopic stage III over adjuvant therapy leads to sharp reduction of therapeutic lymph node dissections (TLND). Overall, the major impact of current developments is that SLNB might soon become obsolete and may be replaced by standard CP-GEP testing of the primary for clinical management, reduction of surgical interventions and simplification of follow up schedules in low risk patients. Thus, we are on the eve of a significant reduction in surgical interventions for melanoma that will come in the upcoming years.

Reconsidering the surgical approach in cutaneous melanoma: does wide local excision after a complete diagnostic excision reduce the risk of recurrence?

OBJECTIVES

This study examines whether wide local excision (WLE) after complete diagnostic excision improves recurrence-free survival (RFS) in clinical stage I/II primary cutaneous melanoma.

BACKGROUND

Since the 1950s, melanoma treatment has included a two-step surgical approach, involving diagnostic excision followed by WLE. WLE aims to achieve locoregional disease control by eliminating potential microsatellites and, thus, minimising the risk of locoregional recurrence and melanoma-related death. However, its impact on RFS is unclear, while it adds morbidity and costs.

METHODS

This retrospective nationwide cohort study analysed pathology reports of a Dutch population-based cohort of newly diagnosed invasive cutaneous melanoma patients who underwent a complete diagnostic excision between January 1st, 2012, and December 31st, 2013. Data were obtained from the Dutch Nationwide Pathology Database (PALGA). Patients with completely excised superficial spreading and nodular melanoma located on the trunk and upper and lower extremities were included. Cox regression showed no significant RFS benefit from WLE.

RESULTS

A total of 6189 eligible patients were included. WLE was not performed in 271 patients (4.4 %). Of those undergoing WLE (n = 5918), residual dermal invasive tumour cells were identified in 0.7 % (n = 44/5918). The overall recurrence rate was 7.7 % (n = 477/6189). Recurrence rates were 7.6 % for WLE cases (local: 2.5 %, nodal: 4.0 %, distant: 1.2 %) and 10.3 % when WLE was omitted. Cox regression showed no significant RFS benefit from WLE.

CONCLUSION

WLE does not significantly improve RFS in patients with completely excised cutaneous superficial spreading and nodular melanoma on the trunk or extremities.

Evaluation of residual tumour in wide local excision for melanoma: A nationwide population-based study

BACKGROUND

Melanoma incidence is increasing, emphasizing the need for optimized management. Wide local excision (WLE) remains the standard for locoregional disease control. The main advantage of WLE is likely in removing microsatellite lesions near the primary tumour if fully excised. This study evaluates the incidence of residual tumour in WLE specimens using a large nationwide cohort. This to refine patient selection and support a more evidence-based approach to surgical management METHODS: A nationwide, population-based study was conducted using data from the Dutch Pathology Databank. Patients diagnosed with melanoma between 2000 and 2023 who had a completely resected tumour with diagnostic excision without reported microsatellite lesions.

RESULTS

Among 44,628 patients undergoing WLE, 2.1 % had residual tumour. Residual tumour was significantly correlated with increased Breslow thickness, ulceration and nodular melanoma subtype. The incidence of residual tumour increased with advancing T stage, from 1.2 % in Tis to 11.2 % in T4b melanomas.

CONCLUSION

The incidence of residual tumour following WLE for melanomas up to T2 is low (< 3 %). Our findings suggest that omission of the WLE for all melanomas up to T2 may well be considered.

Wise or wide (WoW) study protocol: a national, multicentre, prospective, randomised and controlled, parallel group, non-inferiority study to compare single-staged versus two-staged excisions of thin invasive (≤1.0 mm) melanoma

BACKGROUND

Sweden has one of the highest incidence rates of cutaneous melanoma globally, and the incidence is rapidly increasing. Melanoma mortality is linked to the thickness of the primary tumour, with thicker melanomas having a poorer prognosis. Thin invasive melanomas (≤1.0 mm Breslow thickness) have excellent prognosis. Traditionally, the surgical approach for melanoma involves a two-step procedure of a diagnostic excision followed by a wide local excision (WLE) with 10 mm clinical margins. The WLE aims to remove potential microsatellites and residual melanoma, which in theory would prevent loco-regional recurrence and could improve survival. However, recent research questions the necessity of WLE for thin invasive melanomas, given their favourable prognosis, minimal risk of microsatellitosis and low rates of residual melanoma found in WLE tissue specimens.

METHODS AND ANALYSIS

This multicentre, non-inferiority, randomised controlled trial seeks to enrol 2486 patients with thin invasive melanomas that are completely excised with ≥1.5 mm histopathological margins following the diagnostic excision. Patients will be randomly assigned to either a control group that will undergo a WLE with 10 mm clinical margins according to current clinical routine or an experimental group without a WLE. The primary and secondary endpoints are recurrence-free survival at 5 and 10 years, respectively, with tertiary aims including postoperative complications, scar quality, patient satisfaction and quality of life, healthcare resource utilisation as well as differences in biomarkers of recurrent and non-recurrent melanomas. Patients will be assessed at clinical follow-up visits at 3 months as well as at 1, 2, 3, 5 and 10 years.

ETHICS AND DISSEMINATION

Approval of this study was obtained from the Swedish Ethical Review Authority (2024-03274-01). The findings of the study will be presented at international scientific meetings and published in peer-reviewed academic journals.

TRIAL REGISTRATION NUMBER

NCT06363591.

The Frequency of Microsatellite Metastases, Satellite Metastases, and Residual Tumor in Thin Melanomas: A Retrospective Cohort Study

INTRODUCTION

Thin invasive melanomas (Breslow thickness ≤1.0 mm) are increasing in incidence in Sweden, but notably also have a favorable prognosis. Treatment typically involves complete diagnostic excision followed by wide local excision (WLE) to eliminate potential microsatellite and satellite metastases along with residual melanoma.

OBJECTIVES

This study aimed to investigate the frequency of microsatellite and satellite metastases in diagnostic excision specimens and residual melanoma in WLE specimens from thin melanomas.

METHODS

This was a retrospective cohort study including consecutively collected primary thin melanomas excised at Sahlgrenska University Hospital (Gothenburg, Sweden) between January 2014 and December 2020.

RESULTS

Among 1,012 cases, no microsatellites were observed in the diagnostic excisions. Meanwhile, macroscopic satellite metastases were only present in 0.2% of the cases (N=2). Among 887 melanomas undergoing WLE with available data (87.6%), no microsatellites or satellite metastases were found in the extra tissue removed. Of the completely excised melanomas (N=936, 92.5%), only 0.2% (N=2) exhibited residual melanoma in the WLE.

CONCLUSIONS

Our findings align with previous studies suggesting that WLE may result in excessive and unnecessary treatment for completely excised thin melanomas. The requirement of performing WLEs following complete excision of thin melanomas needs to be reevaluated.

Impact of alternative diagnostic labels for melanoma in situ on management choices and psychological outcomes: protocol for an online randomised study

INTRODUCTION

A diagnosis of melanoma in situ presents negligible risk to a person's lifespan or physical well-being, but existing terminology makes it difficult for patients to distinguish these from higher risk invasive melanomas. This study aims to explore whether using an alternative label for melanoma in situ may influence patients' management choices and anxiety levels.

METHODS AND ANALYSIS

This study is a between-subjects randomised online experiment, using hypothetical scenarios. Following consent, eligible participants will be randomised 1:1:1 to three labels: 'melanoma in situ' (control), 'low-risk melanocytic neoplasm' (intervention 1) and 'low-risk melanocytic neoplasm, in situ' (intervention 2). The required sample size is 1668 people. The co-primary outcomes are (1) choice between no further surgery or further surgery to ensure clear histological margins greater than 5 mm and (2) choice between patient-initiated clinical follow-up when needed (patient-led surveillance) and regular routinely scheduled clinical follow-up (clinician-led surveillance). Secondary outcomes include diagnosis anxiety, perceived risk of invasive melanoma and of dying from melanoma and management choice anxiety (after surgery choice and follow-up choice). We will make pairwise comparisons across the three diagnostic label groups using regression models (univariable and multivariable).

ETHICS AND DISSEMINATION

The study has been registered with the Australian New Zealand Clinical Trials Registry (ACTRN12624000740594). Ethics approval has been received from The University of Sydney Human Research Ethics Committee (2024/HE000019). The results of the study will be published in a peer-reviewed medical journal, and a plain language summary of the findings will be shared on the Wiser Healthcare publication page (https://www.wiserhealthcare.org.au/category/publications/).

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ID 386943).

The role of wide local excision of a primary lesion in cutaneous malignant melanoma: a retrospective analysis of its usefulness in local and general control of disease

Currently, wide local excision is recommended after the primary excision of cutaneous melanomas. The definition of margins for wide local excision indicated by the guidelines has remained unchanged over the years, although the reported indications are derived from fairly dated studies in which melanomas tended to be thicker or in advanced stages at diagnosis. This study aimed to retrospectively evaluate the usefulness of wide local excision for local and general control of the disease and to identify patients who had benefited from the wide local excision procedure in terms of prognosis improvement. This retrospective observational study was conducted on patients who had undergone surgery for melanoma at a single institution. The primary endpoint was progression-free survival after wide local excision in patients with or without residual melanoma. The secondary endpoint was to evaluate which patients' demographic features and melanoma histological data were associated with residual melanoma after wide local excision. In the univariate model, melanoma-positive wide local excision resulted in the worst progression-free survival; however, this association was not confirmed in the multivariate model. The results also showed that Breslow thickness was the only factor associated with an increased risk of metastasis to the wide local excision area. According to the receiver operating characteristic analysis, the optimum cutoff value of Breslow's thickness to predict a tumor-positive wide local excision was 2.31 mm for males and 2.4 mm for females.

Doping-Engineered Piezoelectric Ultrathin Nanosheets for Synergistically Piezo-Chemocatalytic Antitumor and Antibacterial Therapies Against Cutaneous Melanoma

The post-surgical melanoma recurrence and wound infections have persistently troubled clinical management. Piezocatalytic therapy features high efficiency in generating reactive oxygen species (ROS) for tumor therapy, but it faces limitations in piezoelectricity and redox-active site availability. Herein, Fe-doped ultrathin Bi4Ti3O12 nanosheets (designated as Fe-UBTO NSs) with synergistically piezo-chemocatalytic activity are engineered for antitumor and antibacterial treatment against cutaneous melanoma. The doping-engineered strategy induces oxygen vacancies and lattice distortions in Fe-UBTO NSs, which narrows bandgap to enhance piezocatalytic 1O2 and H2O2 generation by improving the electron-hole pairs separation, hindering their recombination, and increasing oxygen adsorption. Moreover, Fe doping establishes a piezo-chemocatalytic system, in which the piezocatalysis enables the self-supply of H2O2 and expedites electron transfer in Fenton reactions, inducing increased ·OH production. Besides, the atomic-level thickness and expanded surface area enhance the sensitivity to ultrasound stimuli and expose more redox-active sites, augmenting the piezo-chemocatalytic efficiency, and ultimately leading to abundant ROS generation. The Fe-UBTO-mediated piezo-chemocatalytic therapy causes intracellular oxidative stress, triggering apoptosis and excessive autophagy of tumor cells. Moreover, this strategy accelerates wound healing by facilitating sterilization, angiogenesis, and collagen deposition. This work provides distinct options to develop doping-engineered ultrathin nanosheets with augmented piezo-chemocatalytic activity for postoperative management of cutaneous melanoma.

Management of Localized Melanoma in the Anti-PD-1 Era

PURPOSE OF REVIEW

The management of cutaneous melanoma has rapidly progressed over the past decade following the introduction of effective systemic therapies. Given the large number of recent clinical trials which have dramatically altered the management of these patients, an updated review of the current evidence regarding the management of localized melanoma is needed.

RECENT FINDINGS

The role of effective systemic therapies in earlier stages (I-III) melanoma, both in adjuvant and neoadjuvant settings is rapidly changing the role of surgery in the management cutaneous melanoma, particularly regarding surgical safety margins for wide local excision (WLE), the role of sentinel lymph node biopsy (SLNB) and the extent of lymph node dissections. The randomized phase 2 SWOG1801 trial has demonstrated superiority of neoadjuvant-adjuvant anti-PD1 therapy in improving event-free survival by 23% at 2-years over adjuvant anti-PD-1 therapy only. Furthermore, the PRADO trial has suggested a more tailored approach both the extent of surgery as well as adjuvant therapy can safely and effectively be done, depending on the response to initial neoadjuvant immunotherapy. These results await validation and it is expected that in 2024 the phase 3 Nadina trial (NCT04949113) will definitively establish neo-adjuvant combination immunotherapy as the novel standard. This will further redefine the management of localized melanoma. The use of effective systemic therapies will continue to evolve in the next decade and, together with new emerging diagnostic and surveillance techniques, will likely reduce the extent of routine surgery for stage I-III melanoma.

Self-supplying Cu2+ and H2O2 synergistically enhancing disulfiram-mediated melanoma chemotherapy

Disulfiram (DSF) can target and kill cancer cells by disrupting cellular degradation of extruded proteins and has therefore received particular attention for its tumor chemotherapeutic potential. However, the uncontrollable Cu2+/DSF ratio reduces the efficacy of DSF-mediated chemotherapy. Herein, self-supplying Cu2+ and oxidative stress synergistically enhanced DSF-mediated chemotherapy is proposed for melanoma-based on PVP-coated CuO2 nanodots (CPNDs). Once ingested, DSF is broken down to diethyldithiocarbamate (DTC), which is delivered into a tumor via the circulation. Under the acidic tumor microenvironment, CPNDs produce sufficient Cu2+ and H2O2. DTC readily chelates Cu2+ ions to generate CuET, which shows antitumor efficacy. CuET-mediated chemotherapy can be enhanced by H2O2. Sufficient Cu2+ generation can guarantee the maximum efficacy of DSF-mediated chemotherapy. Furthermore, released Cu2+ can be reduced to Cu+ by glutathione (GSH) and O2- in tumor cells, and Cu+ can react with H2O2 to generate toxic hydroxyl radicals (·OH) via a Fenton-like reaction, promoting the efficacy of CuET. Therefore, this study hypothesizes that employing CPNDs instead of Cu2+ ions could enhance DSF-mediated melanoma chemotherapy, providing a simple but efficient strategy for achieving chemotherapeutic efficacy.

A Review of Contemporary Guidelines and Evidence for Wide Local Excision in Primary Cutaneous Melanoma Management

Surgical wide local excision (WLE) remains the current standard of care for primary cutaneous melanoma. WLE is an elective procedure that aims to achieve locoregional disease control with minimal functional and cosmetic impairment. Despite several prospective randomised trials, the optimal extent of excision margin remains controversial, and this is reflected in the persistent lack of consensus in guidelines globally. Furthermore, there is now the added difficulty of interpreting existing trial data in the context of the evolving role of surgery in the management of melanoma, with our increased understanding of clinicopathologic and genomic prognostic markers leading to the often routine use of sentinel node biopsy (SNB) as a staging procedure, in addition to the development of adjuvant systemic therapies for high-risk disease. An ongoing trial, MelMarT-II, has been designed with the aim of achieving a definitive answer to guide this fundamental surgical decision.

The "Great Debate" at Melanoma Bridge 2022, Naples, December 1st-3rd, 2022

The Great Debate session at the 2022 Melanoma Bridge congress (December 1-3) featured counterpoint views from leading experts on five contemporary topics of debate in the management of melanoma. The debates considered the choice of anti-lymphocyte-activation gene (LAG)-3 therapy or ipilimumab in combination with anti-programmed death (PD)-1 therapy, whether anti-PD-1 monotherapy is still acceptable as a comparator arm in clinical trials, whether adjuvant treatment of melanoma is still a useful treatment option, the role of adjuvant therapy in stage II melanoma, what role surgery will continue to have in the treatment of melanoma. As is customary in the Melanoma Bridge Great Debates, the speakers are invited by the meeting Chairs to express one side of the assigned debate and the opinions given may not fully reflect personal views. Audiences voted in favour of either side of the argument both before and after each debate.