International Center-Level Variation in Utilization of Completion Lymph Node Dissection and Adjuvant Systemic Therapy for Sentinel Lymph Node-Positive Melanoma at Major Referral Centers.

OBJECTIVE: The aim of this study was to determine overall trends and center-level variation in utilization of completion lymph node dissection (CLND) and adjuvant systemic therapy for sentinel lymph node (SLN)-positive melanoma. SUMMARY BACKGROUND DATA: Based on recent clinical trials, management options for SLN-positive melanoma now include effective adjuvant systemic therapy and nodal observation instead of CLND. It is unknown how these findings have shaped practice or how these contemporaneous developments have influenced their respective utilization. METHODS: We performed an international cohort study at 21 melanoma referral centers in Australia, Europe, and the United States that treated adults with SLN-positive melanoma and negative distant staging from July 2017 to June 2019. We used generalized linear and multinomial logistic regression models with random intercepts for each center to assess center-level variation in CLND and adjuvant systemic treatment, adjusting for patient and disease-specific characteristics. RESULTS: Among 1109 patients, performance of CLND decreased from 28% to 8% and adjuvant systemic therapy use increased from 29 to 60%. For both CLND and adjuvant systemic treatment, the most influential factors were nodal tumor size, stage, and location of treating center. There was notable variation among treating centers in management of stage IIIA patients and use of CLND with adjuvant systemic therapy versus nodal observation alone for similar risk patients. CONCLUSIONS: There has been an overall decline in CLND and simultaneous adoption of adjuvant systemic therapy for patients with SLN-positive melanoma though wide variation in practice remains. Accounting for differences in patient mix, location of care contributed significantly to the observed variation.

The efficacy of immune checkpoint blockade for melanoma in-transit with or without nodal metastases - A multicenter cohort study.

PURPOSE: Guidelines addressing melanoma in-transit metastasis (ITM) recommend immune checkpoint inhibitors (ICI) as a first-line treatment option, despite the fact that there are no efficacy data available from prospective trials for exclusively ITM disease. The study aims to analyze the outcome of patients with ITM treated with ICI based on data from a large cohort of patients treated at international referral clinics. METHODS: A multicenter retrospective cohort study of patients treated between January 2015 and December 2020 from Australia, Europe, and the USA, evaluating treatment with ICI for ITM with or without nodal involvement (AJCC8 N1c, N2c, and N3c) and without distant disease (M0). Treatment was with PD-1 inhibitor (nivolumab or pembrolizumab) and/or CTLA-4 inhibitor (ipilimumab). The response was evaluated according to the RECIST criteria modified for cutaneous lesions. RESULTS: A total of 287 patients from 21 institutions in eight countries were included. Immunotherapy was first-line treatment in 64 (22%) patients. PD-1 or CTLA-4 inhibitor monotherapy was given in 233 (81%) and 23 (8%) patients, respectively, while 31 (11%) received both in combination. The overall response rate was 56%, complete response (CR) rate was 36%, and progressive disease (PD) rate was 32%. Median PFS was ten months (95% CI 7.4-12.6 months) with a one-, two-, and five-year PFS rate of 48%, 33%, and 18%, respectively. Median MSS was not reached, and the one-, two-, and five-year MSS rates were 95%, 83%, and 71%, respectively. CONCLUSION: Systemic immunotherapy is an effective treatment for melanoma ITM. Future studies should evaluate the role of systemic immunotherapy in the context of multimodality therapy, including locoregional treatments such as surgery, intralesional therapy, and regional therapies.

Active surveillance of patients who have sentinel node positive melanoma: An international, multi-institution evaluation of adoption and early outcomes after the Multicenter Selective Lymphadenectomy Trial II (MSLT-2).

BACKGROUND: For patients with sentinel lymph node (SLN)-positive cutaneous melanoma, the Second Multicenter Selective Lymphadenectomy trial demonstrated equivalent disease-specific survival (DSS) with active surveillance using nodal ultrasound versus completion lymph node dissection (CLND). Adoption and outcomes of active surveillance in clinical practice and in adjuvant therapy recipients are unknown. METHODS: In a retrospective cohort of SLN-positive adults treated at 21 institutions in Australia, Europe, and the United States from June 2017 to November 2019, the authors evaluated the impact of active surveillance and adjuvant therapy on all-site recurrence-free survival (RFS), isolated nodal RFS, distant metastasis-free survival (DMFS), and DSS using Kaplan-Meier curves and Cox proportional hazard models. RESULTS: Among 6347 SLN biopsies, 1154 (18%) were positive and had initial negative distant staging. In total, 965 patients (84%) received active surveillance, 189 (16%) underwent CLND. Four hundred thirty-nine patients received adjuvant therapy (surveillance, 38%; CLND, 39%), with the majority (83%) receiving anti-PD-1 immunotherapy. After a median follow-up of 11 months, 220 patients developed recurrent disease (surveillance, 19%; CLND, 22%), and 24 died of melanoma (surveillance, 2%; CLND, 4%). Sixty-eight patients had an isolated nodal recurrence (surveillance, 6%; CLND, 4%). In patients who received adjuvant treatment without undergoing prior CLND, all isolated nodal recurrences were resectable. On risk-adjusted multivariable analyses, CLND was associated with improved isolated nodal RFS (hazard ratio [HR], 0.36; 95% CI, 0.15-0.88), but not all-site RFS (HR, 0.68; 95% CI, 0.45-1.02). Adjuvant therapy improved all-site RFS (HR, 0.52; 95% CI, 0.47-0.57). DSS and DMFS did not differ by nodal management or adjuvant treatment. CONCLUSIONS: Active surveillance has been adopted for most SLN-positive patients. At initial assessment, real-world outcomes align with randomized trial findings, including in adjuvant therapy recipients. LAY SUMMARY: For patients with melanoma of the skin and microscopic spread to lymph nodes, monitoring with ultrasound is an alternative to surgically removing the remaining lymph nodes. The authors studied adoption and real-world outcomes of ultrasound monitoring in over 1000 patients treated at 21 centers worldwide, finding that most patients now have ultrasounds instead of surgery. Although slightly more patients have cancer return in the lymph nodes with this strategy, typically, it can be removed with delayed surgery. Compared with up-front surgery, ultrasound monitoring results in the same overall risk of melanoma coming back at any location or of dying from melanoma.

Molecular Aspects of the Isolated Limb Infusion Procedure.

For decades, isolated limb infusion (ILI) and hyperthermic isolated limb perfusion (HILP) have been used to treat melanoma in-transit metastases and unresectable sarcoma confined to the limb utilizing the effect of loco-regional high-dose chemotherapy to the isolated limb. Both procedures are able to provide high response rates in patients with numerous or bulky lesions in whom other loco-regional treatments are becoming ineffective. In comparison to systemic therapies, on the other hand, ILI and HILP have the advantage of not being associated with systemic side-effects. Although in principle ILI and HILP are similar procedures, ILI is technically simpler to perform and differs from HILP in that it takes advantage of the hypoxic and acidotic environment that develops in the isolated limb, potentiating anti-tumour activity of the cytotoxic agents melphalan +/- actinomycin-D. Due to its simplicity, ILI can be used in both preclinical and clinical studies to test new cytotoxic regimens and combinations with the aim to overcome tumour resistance. In the future, administration of cytotoxic agents by ILI, in combination with systemic treatments such as BRAF/MEK/KIT inhibitors, immunotherapy (CTLA-4 blockade), and/or programmed death (PD-1) pathway inhibitors, has the potential to improve responses further by inducing increased tumour cell death while limiting the ability of the tumour to suppress the immune response.

Surveillance of Sentinel Node-Positive Melanoma Patients with Reasons for Exclusion from MSLT-II: Multi-Institutional Propensity Score Matched Analysis.

BACKGROUND: In sentinel lymph node (SLN)-positive melanoma, two randomized trials demonstrated equivalent melanoma-specific survival with nodal surveillance vs completion lymph node dissection (CLND). Patients with microsatellites, extranodal extension (ENE) in the SLN, or >3 positive SLNs constitute a high-risk group largely excluded from the randomized trials, for whom appropriate management remains unknown. STUDY DESIGN: SLN-positive patients with any of the three high-risk features were identified from an international cohort. CLND patients were matched 1:1 with surveillance patients using propensity scores. Risk of any-site recurrence, SLN-basin-only recurrence, and melanoma-specific mortality were compared. RESULTS: Among 1,154 SLN-positive patients, 166 had ENE, microsatellites, and/or >3 positive SLN. At 18.5 months median follow-up, 49% had recurrence (vs 26% in patients without high-risk features, p < 0.01). Among high-risk patients, 52 (31%) underwent CLND and 114 (69%) received surveillance. Fifty-one CLND patients were matched to 51 surveillance patients. The matched cohort was balanced on tumor, nodal, and adjuvant treatment factors. There were no significant differences in any-site recurrence (CLND 49%, surveillance 45%, p = 0.99), SLN-basin-only recurrence (CLND 6%, surveillance 14%, p = 0.20), or melanoma-specific mortality (CLND 14%, surveillance 12%, p = 0.86). CONCLUSIONS: SLN-positive patients with microsatellites, ENE, or >3 positive SLN constitute a high-risk group with a 2-fold greater recurrence risk. For those managed with nodal surveillance, SLN-basin recurrences were more frequent, but all-site recurrence and melanoma-specific mortality were comparable to patients treated with CLND. Most recurrences were outside the SLN-basin, supporting use of nodal surveillance for SLN-positive patients with microsatellites, ENE, and/or >3 positive SLN.

Factors predicting toxicity and response following isolated limb infusion for melanoma: An international multi-centre study.

INTRODUCTION: Isolated limb infusion (ILI) is a minimally-invasive procedure for delivering high-dose regional chemotherapy to treat melanoma in-transit metastases confined to a limb. The aim of this international multi-centre study was to identify predictive factors for toxicity and response. METHODS: Data of 687 patients who underwent a first ILI for melanoma in-transit metastases confined to the limb between 1992 and 2018 were collected at five Australian and four US tertiary referral centres. RESULTS: After ILI, predictive factors for increased limb toxicity (Wieberdink grade III/IV limb toxicity, n = 192, 27.9%) were: female gender, younger age, procedures performed before 2005, lower limb procedures, higher melphalan dose, longer drug circulation and ischemia times, and increased tissue hypoxia. No patient experienced grade V toxicity (necessitating amputation). A complete response (n = 199, 28.9%) was associated with a lower stage of disease, lower burden of disease (BOD) and thinner Breslow thickness of the primary melanoma. Additionally, an overall response (combined complete and partial response, n = 441, 64.1%) was associated with female gender, Australian centres, procedures performed before 2005, lower limb procedures and lower actinomycin-D doses. On multivariate analysis, higher melphalan dose remained a predictive factor for toxicity, while lower stage of disease and lower BOD remained predictive factors for overall response. CONCLUSION: ILI is safe and effective to treat melanoma in-transit metastases. Predictive factors for toxicity and response identified in this study will allow improved patient selection and optimization of intra-operative parameters to increase response rates, while keeping toxicity low.

International Multicenter Experience of Isolated Limb Infusion for In-Transit Melanoma Metastases in Octogenarian and Nonagenarian Patients.

BACKGROUND: Isolated limb infusion (ILI) is used to treat in-transit melanoma metastases confined to an extremity. However, little is known about its safety and efficacy in octogenarians and nonagenarians (ON). PATIENTS AND METHODS: ON patients (≥ 80 years) who underwent a first ILI for American Joint Committee on Cancer seventh edition stage IIIB/IIIC melanoma between 1992 and 2018 at nine international centers were included and compared with younger patients (< 80 years). A cytotoxic drug combination of melphalan and actinomycin-D was used. RESULTS: Of the 687 patients undergoing a first ILI, 160 were ON patients (median age 84 years; range 80-100 years). Compared with the younger cohort (n = 527; median age 67 years; range 29-79 years), ON patients were more frequently female (70.0% vs. 56.9%; p = 0.003), had more stage IIIB disease (63.8 vs. 53.3%; p = 0.02), and underwent more upper limb ILIs (16.9% vs. 9.5%; p = 0.009). ON patients experienced similar Wieberdink limb toxicity grades III/IV (25.0% vs. 29.2%; p = 0.45). No toxicity-related limb amputations were performed. Overall response for ON patients was 67.3%, versus 64.6% for younger patients (p = 0.53). Median in-field progression-free survival was 9 months for both groups (p = 0.88). Median distant progression-free survival was 36 versus 23 months (p = 0.16), overall survival was 29 versus 40 months (p < 0.0001), and melanoma-specific survival was 46 versus 78 months (p = 0.0007) for ON patients compared with younger patients, respectively. CONCLUSIONS: ILI in ON patients is safe and effective with similar response and regional control rates compared with younger patients. However, overall and melanoma-specific survival are shorter.

First Eastern European experience of isolated limb infusion for in-transit metastatic melanoma confined to the limb: Is it still an effective treatment option in the modern era?

BACKGROUND: Isolated limb infusion (ILI) with cytotoxic agents is a simple and effective treatment option for patients with melanoma in-transit metastases (ITMs) confined to an extremity. Data for ILIs performed in Europe are sparse and to date no Eastern European ILI experience has been reported. The aim of the current study was to evaluate the efficacy of ILI in Estonia. PATIENTS AND METHODS: Data for twenty-one patients were collected and analysed. All patients had melanoma ITMs and underwent an ILI between January 2012 and May 2018. The cytotoxic drug combination of melphalan and actinomycin-D was used. Drug circulation times were 20-30 min under mildly hyperthermic conditions (38-39 °C). Primary outcome measures were treatment response and overall survival. RESULTS: Nineteen lower limb and two upper limb ILIs were performed. The female to male ratio was 18:3. The overall response rate (complete + partial response) was 76% (n = 16), with a complete response in 38% (n = 8). The overall long-term limb salvage rate was 90% (n = 19). During follow-up, eight patients (38%) died, two due to metastatic melanoma. Five-year overall survival was 57%. CONCLUSION: This first Eastern European report of ILI for melanoma ITMs shows results comparable to those from other parts of the world. In this era of effective targeted and immune therapies, ILI remains a useful treatment option, with a high overall response rate and durable responses in patients with melanoma ITMs confined to a limb.

Human Peripheral Blood Eosinophils Express High Levels of the Purinergic Receptor P2X4.

Extracellular nucleotides are important mediators of cell activation and trigger multiple responses via membrane receptors known as purinergic receptors (P2). P2X receptors are ligand-gated ion channels, activated by extracellular ATP. P2X4 is one of the most sensitive purinergic receptors, that is typically expressed by neurons, microglia, and some epithelial and endothelial cells. P2X4 mediates neuropathic pain via brain-derived neurotrophic factor and is also involved in inflammation in response to high ATP release. It is therefore involved in multiple inflammatory pathologies as well as neurodegenerative diseases. We have produced monoclonal antibodies (mAb) directed against this important human P2X4 receptor. Focusing on two mAbs, we showed that they also recognize mouse and rat P2X4. We demonstrated that these mAbs can be used in flow cytometry, immunoprecipitation, and immunohistochemistry, but not in Western blot assays, indicating that they target conformational epitopes. We also characterized the expression of P2X4 receptor on mouse and human peripheral blood lymphocytes (PBL). We showed that P2X4 is expressed at the surface of several leukocyte cell types, with the highest expression level on eosinophils, making them potentially sensitive to adenosine triphosphate (ATP). P2X4 is expressed by leucocytes, in human and mouse, with a significant gender difference, males having higher surface expression levels than females. Our findings reveal that PBL express significant levels of P2X4 receptor, and suggest an important role of this receptor in leukocyte activation by ATP, particularly in P2X4high expressing eosinophils.

2-cm versus 4-cm surgical excision margins for primary cutaneous melanoma thicker than 2 mm: long-term follow-up of a multicentre, randomised trial.

BACKGROUND: The optimal surgical excision margins are uncertain for patients with thick (>2 mm) localised cutaneous melanomas. In our previous report of this multicentre, randomised controlled trial, with a median follow-up of 6·7 years, we showed that a narrow excision margin (2 cm vs 4 cm) did not affect melanoma-specific nor overall survival. Here, we present extended follow-up of this cohort. METHODS: In this open-label, multicentre randomised controlled trial, we recruited patients from 53 hospitals in Sweden, Denmark, Estonia, and Norway. We enrolled clinically staged patients aged 75 years or younger diagnosed with localised cutaneous melanoma thicker than 2 mm, and with primary site on the trunk or upper or lower extremities. Patients were randomly allocated (1:1) to treatment either with a 2-cm or a 4-cm excision margin. A physician enrolled the patients after histological confirmation of a cutaneous melanoma thicker than 2 mm. Some patients were enrolled by a physician acting as responsible for clinical care and as a trial investigator (follow-up, data collection, and manuscript writing). In other cases physicians not involved in running the trial enrolled patients. Randomisation was done by telephone call to a randomisation office, by sealed envelope, or by computer generated lists using permuted blocks. Patients were stratified according to geographical region. No part of the trial was masked. The primary outcome in this extended follow-up study was overall survival and the co-primary outcome was melanoma-specific survival. All analyses were done on an intention-to-treat basis. The study is registered with ClinicalTrials.gov, number NCT03638492. FINDINGS: Between Jan 22, 1992, and May 19, 2004, 936 clinically staged patients were recruited and randomly assigned to a 4-cm excision margin (n=465) or a 2-cm excision margin (n=471). At a median overall follow-up of 19·6 years (235 months, IQR 200-260), 621 deaths were reported-304 (49%) in the 2-cm group and 317 (51%) in the 4-cm group (unadjusted HR 0·98, 95% CI 0·83-1·14; p=0·75). 397 deaths were attributed to cutaneous melanoma-192 (48%) in the 2-cm excision margin group and 205 (52%) in the 4-cm excision margin group (unadjusted HR 0·95, 95% CI 0·78-1·16, p=0·61). INTERPRETATION: A 2-cm excision margin was safe for patients with thick (>2 mm) localised cutaneous melanoma at a follow-up of median 19·6 years. These findings support the use of 2-cm excision margins in current clinical practice. FUNDING: The Swedish Cancer Society, Stockholm Cancer Society, the Swedish Society for Medical Research, Radiumhemmet Research funds, Stockholm County Council, Wallström funds.