Risk stratification of sentinel node–positive melanoma patients defines surgical management and adjuvant therapy treatment considerations

Stage III Melanoma: A Proposed Staging Model That Outperforms the American Joint Committee on Cancer Eighth Edition Staging System

National Comprehensive Cancer Network guidelines state that clinical stage III melanoma patients may undergo ultrasound surveillance of the nodal basin in lieu of complete lymph node dissection (CLND). This has led to an inability to accurately classify patients according to the American Joint Committee on Cancer (AJCC) eighth edition staging system because it uses the total number of positive lymph nodes from the CLND to assign a pathologic N stage. We propose a new model for clinical stage III melanoma patients that does not rely on the total number of positive lymph nodes. Instead, it uses Breslow depth, ulceration status, sentinel lymph node metastasis size, and extracapsular extension to stratify patients into groups 1 to 4. We compared our model's ability to predict melanoma-specific survival (MSS), distant metastasis-free survival (DMFS) and locoregional recurrence, and distant metastasis-free survival (DMFS-LRFS) to the current AJCC system with and without CLND-data using a Cox proportional hazards model and Akaike Information Criteria weights. Although not reaching our predetermined level of statistical significance of 95%, our model was 5 times more likely to better predict MSS compared with the AJCC model with CLND. In addition, our model was significantly better than the AJCC model without CLND in predicting MSS. Our model performed significantly better than the AJCC model in predicting DMFS and DMFS-LRFS regardless of whether data from CLND were included.

Interferon-gamma signature as prognostic and predictive marker in macroscopic stage III melanoma

BACKGROUND

A substantial proportion of patients with macroscopic stage III melanoma do not benefit sufficiently from adjuvant anti-PD-1 therapy, as they either recur despite therapy or would never have recurred. To better inform adjuvant treatment selection, we have performed translational analyses to identify prognostic and predictive biomarkers.

PATIENTS AND METHODS

Two cohorts of patients with macroscopic stage III melanoma from an ongoing biobank study were included. Clinical data were compared between an observation cohort (cohort 1) and an adjuvant intention cohort (cohort 2). RNA sequencing for translational analyses was performed and treatment subgroups (cohort 1A and cohort 2A) were compared for possible biomarkers, using a cut-off based on the treatment-naïve patients. In addition, two validation cohorts (Melanoma Institute Australia (MIA) and University Medical Centre Utrecht (UMCU)) were obtained.

RESULTS

After a median follow-up of 26 months of the 98 patients in our discovery set, median recurrence-free survival (RFS) was significantly longer for the adjuvant intention cohort (cohort 2, n=49) versus the observation cohort (cohort 1, n=49). Median overall survival was not reached for either cohort, nor significantly different. In observation cohort 1A (n=24), RFS was significantly longer for patients with high interferon-gamma (IFNγ) score (p=0.002); for adjuvant patients of cohort 2A (n=24), a similar trend was observed (p=0.086). Patients with high B cell score had a longer RFS in cohort 1A, but no difference was seen in cohort 2A. The B cell score based on RNA correlated with CD20+ cells in tumor area but was not independent from the IFNγ score. In the MIA validation cohort (n=44), longer RFS was observed for patients with high IFNγ score compared with low IFNγ score (p=0.046), no difference in RFS was observed according to the B cell score. In both the observation (n=11) and the adjuvant (n=11) UMCU validation cohorts, no difference in RFS was seen for IFNγ and B cell.

CONCLUSIONS

IFNγ has shown to be a prognostic marker in both patients who were and were not treated with adjuvant therapy. B cell score was prognostic but did not improve accuracy over IFNγ. Our study confirmed RFS benefit of adjuvant anti-PD-1 for patients with macroscopic stage III melanoma.

Case report: Patient specific combination of surgery and immunotherapy in advanced squamous cell carcinoma of the head and neck - a case series and review of literature

BACKGROUND

Prognosis of patients with recurrent or metastatic head and neck cancer is generally poor. Adjuvant immunotherapy (IT) featuring immune checkpoint inhibition (ICI) is standard of care in advanced stage head and neck squamous cell carcinoma (HNSCC) and cutaneous squamous cell carcinoma (CSCC). ICI response rates in CSCC are described as higher than in HNSCC. IT is constantly shifting into earlier disease stages which confronts the surgeon with immunotherapeutically pre-treated patients. It is therefore becoming increasingly difficult to assess which patients with symptomatic tumor disease and a lack of curative surgical option might benefit from salvage surgery.

CASE PRESENTATIONS

The following 6 cases describe therapeutic decision-making regarding ICI and (salvage) surgery in patients with advanced stage HNSCC or CSCC. Cases A and B focus on neoadjuvant ICI followed by salvage surgery. In Cases C and D salvage surgery was performed after short-term stabilization with partial response to ICI. The last two cases (Cases E and F) address the surgical approach after failure of ICI. All cases are discussed in the context of the current study landscape and with focus on individual decision-making. For better understanding, a timetable of the clinical course is given for each case.

CONCLUSIONS

ICI is rapidly expanding its frontiers into the neoadjuvant setting, frequently confronting the surgeon with heavily pretreated patients. Salvage surgery is a viable therapeutic concept despite the rise of systemic treatment options. Decision-making on surgical intervention in case of a salvage surgery remains an individual choice. For neoadjuvant ICI monitoring regarding pathological tumor response or tumor necrosis rate, we suggest correlation between the initial biopsy and the definite tumor resectate in order to increase its significance as a surrogate marker. Scheduling of neoadjuvant ICI should be further investigated, as recent studies indicate better outcomes with shorter time frames.

Using a Clinicopathologic and Gene Expression (CP-GEP) Model to Identify Stage I-II Melanoma Patients at Risk of Disease Relapse

Background: The current standard of care for patients without sentinel node (SN) metastasis (i.e., stage I−II melanoma) is watchful waiting, while >40% of patients with stage IB−IIC will eventually present with disease recurrence or die as a result of melanoma. With the prospect of adjuvant therapeutic options for patients with a negative SN, we assessed the performance of a clinicopathologic and gene expression (CP-GEP) model, a model originally developed to predict SN metastasis, to identify patients with stage I−II melanoma at risk of disease relapse. Methods: This study included patients with cutaneous melanoma ≥18 years of age with a negative SN between October 2006 and December 2017 at the Sahlgrenska University Hospital (Sweden) and Erasmus MC Cancer Institute (The Netherlands). According to the CP-GEP model, which can be applied to the primary melanoma tissue, the patients were stratified into high or low risk of recurrence. The primary aim was to assess the 5-year recurrence-free survival (RFS) of low- and high-risk CP-GEP. A secondary aim was to compare the CP-GEP model with the EORTC nomogram, a model based on clinicopathological variables only. Results: In total, 535 patients (stage I−II) were included. CP-GEP stratification among these patients resulted in a 5-year RFS of 92.9% (95% confidence interval (CI): 86.4−96.4) in CP-GEP low-risk patients (n = 122) versus 80.7% (95%CI: 76.3−84.3) in CP-GEP high-risk patients (n = 413; hazard ratio 2.93 (95%CI: 1.41−6.09), p < 0.004). According to the EORTC nomogram, 25% of the patients were classified as having a ‘low risk’ of recurrence (96.8% 5-year RFS (95%CI 91.6−98.8), n = 130), 49% as ‘intermediate risk’ (88.4% 5-year RFS (95%CI 83.6−91.8), n = 261), and 26% as ‘high risk’ (61.1% 5-year RFS (95%CI 51.9−69.1), n = 137). Conclusion: In these two independent European cohorts, the CP-GEP model was able to stratify patients with stage I−II melanoma into two groups differentiated by RFS.

The role of sentinel node tumor burden in modeling the prognosis of melanoma patients with positive sentinel node biopsy: an Italian melanoma intergroup study (N = 2,086)

Background

The management of melanoma patients with metastatic melanoma in the sentinel nodes (SN) is evolving based on the results of trials questioning the impact of completion lymph node dissection (CLND) and demonstrating the efficacy of new adjuvant treatments. In this landscape, new prognostic tools for fine risk stratification are eagerly sought to optimize the therapeutic path of these patients.

Methods

A retrospective cohort of 2,086 patients treated with CLND after a positive SN biopsy in thirteen Italian Melanoma Centers was reviewed. Overall survival (OS) was the outcome of interest; included independent variables were the following: age, gender, primary melanoma site, Breslow thickness, ulceration, sentinel node tumor burden (SNTB), number of positive SN, non-sentinel lymph nodes (NSN) status. Univariate and multivariate survival analyses were performed using the Cox proportional hazard regression model.

Results

The 3-year, 5-year and 10-year OS rates were 79%, 70% and 54%, respectively. At univariate analysis, all variables, except for primary melanoma body site, were found to be statistically significant prognostic factors. Multivariate Cox regression analysis indicated that older age (P < 0.0001), male gender (P = 0.04), increasing Breslow thickness (P < 0.0001), presence of ulceration (P = 0.004), SNTB size (P < 0.0001) and metastatic NSN (P < 0.0001) were independent negative predictors of OS.

Conclusion

The above results were utilized to build a nomogram in order to ease the practical implementation of our prognostic model, which might improve treatment personalization.

Mesenchymal-epithelial transition factor (MET) immunoreactivity in positive sentinel nodes from patients with melanoma

OBJECTIVE

Patients with cutaneous melanoma and a positive sentinel node (SN) are currently eligible for adjuvant treatment with targeted therapy and immune checkpoint inhibitors. Near-infrared (NIR) fluorescence imaging could be an alternative and less invasive tool for SN biopsy to select patients for adjuvant treatment. One potential target for NIR is the mesenchymal-epithelial transition factor (MET). This study aimed to assess MET immunoreactivity in positive SNs and to evaluate its potential diagnostic, prognostic and therapeutic value.

METHODS

In this retrospective study, positive SN samples from patients with primary cutaneous melanoma were collected to assess MET immunoreactivity. To this end, paraffin-embedded SNs were stained for MET (monoclonal antibody D1C2). A 4-point Histoscore was used to determine cytoplasmic and membranous immunoreactivity (0 negative/1 weak/2 moderate/3 strong). Samples were considered positive when ≥10% of the cancer cells showed MET expression (staining intensity ≥1). Patient and clinicopathological characteristics were used for descriptive statistics, binary logistic regression, and survival analyses.

RESULTS

Positive MET immunohistochemistry was observed in 24 out of 37 samples (65%). No statistically significant associations were found between MET positivity and the following prognostic factors: Breslow thickness (P = 0.961), ulceration (P = 1.000), and SN tumor burden (P = 0.792). According to MET positivity, Kaplan-Meier curves showed no significant differences in survival.

CONCLUSION

This exploratory study found no evidence to support MET immunoreactivity in positive SNs as a possible diagnostic or prognostic indicator in patients with melanoma.

MelRisk: Using neutrophil-to-lymphocyte ratio to improve risk prediction models for metastatic cutaneous melanoma in the sentinel lymph node

BACKGROUND

Identifying metastatic melanoma in the sentinel lymph node (SLN) is important because 80% of SLN biopsies are negative and 11% of patients develop complications. The neutrophil-to-lymphocyte ratio (NLR), a biomarker of micrometastatic disease, could improve prediction models for SLN status. We externally validated existing models and developed 'MelRisk' prognostic score to better predict SLN metastasis.

METHODS

The models were externally validated using data from a multicenter cohort study of 1,251 adults. Additionally, we developed and internally validated a new prognostic score `MelRisk', using candidate predictors derived from the extant literature.

RESULTS

The Karakousis model had a C-statistic of 0.58 (95% CI, 0.54-0.62). The Sondak model had a C-statistic of 0.57 (95% CI 0.53-0.61). The MIA model had a C-statistic of 0.60 (95% CI. 0.56-0.64). Our 'MelRisk' model (which used Breslow thickness, ulceration, age, anatomical site, and the NLR) showed an adjusted C-statistic of 0.63 (95% CI, 0.56-0.64).

CONCLUSION

Our prediction tool is freely available in the Google Play Store and Apple App Store, and we invite colleagues to externally validate its performance .

SPECT/CT-Guided Surgical Removal of a Positive External Iliac Sentinel Node in Primary Umbilical Melanoma: Report of a Case, and Up-to-Date Review of the Literature

Primary umbilical melanoma is rare tumor, representing about 5% of all umbilical malignancies.The lymphatic drainage from the tumor is challenging and can be to inguinal, axillary and retroperitoneal nodes. Dynamic and static lymphoscintigraphy with single-photon emission tomography/computed tomography (SPECT/CT) and sentinel lymph node biopsy (SLNB) is a widely validated technique in patients with clinically localized melanoma to search for and quantify nodal spread of cutaneous melanoma. Moreover, it offers the surgeon the preoperative information about the number and location of the sentinel lymph nodes (SLNs), which makes SLNB easier and quicker. This is the first report of an ulcerated thick melanoma of the umbilicus metastasizing only to an external iliac lymph-node without involvement of superficial inguinal SLNs. The preoperative high-resolution ultrasound (HR-US) examination of the regional lymph node field had been normal. This case-report shows how addition of SPECT/CT to planar imaging in a patient with clinically localized umbilical melanoma can help avoid incomplete SLNB when a deep SLN is not removed. A literature review of umbilical melanoma is also provided.

Prevention of Secondary Lymphedema after Complete Lymph Node Dissection in Melanoma Patients: The Role of Preventive Multiple Lymphatic-Venous Anastomosis in Observational Era

Background and Objectives: Current guidelines have limited the performance of complete lymph node dissection (CLND) for patients with clinically detectable lymphatic metastases. Despite the limitations of this surgical procedure, secondary lymphedema (SL) is an unsolved problem that affects approximately 20% of patients undergoing CLND. Preventive lymphatic–venous micro-anastomoses (PMLVA) has already demonstrated its efficacy in the prevention of SL in melanoma patients with a positive sentinel lymph node biopsy (SLNB), but the efficacy of this procedure is not demonstrated in patients with clinically detectable lymphatic metastases. Materials and Methods: This retrospective cohort study, was performed in two observation periods. Until March 2018, CLND was proposed to all subjects with positive-SLNB andPMLVA was performed in a subgroup of patients with risk factors for SL (Group 1). From April 2018, according to the modification of melanoma guidelines, all patients with detectable metastatic lymph nodes underwent PMLVA during CLND (Group 2). The frequency of lymphedema in subjects undergoing PMLVA was compared with the control group. Results: Database evaluation revealed 172 patients with melanoma of the trunk with follow-up information for at least 6 mounts. Twenty-three patients underwent PMLVA during CLND until March 2018, 29 from April 2018, and 120 subjects underwent CLND without any preventive surgery (control Group). The frequency of SL was significantly lower in both Group 1 (4.3% vs. 24.2%, p = 0.03) and Group 2 (3.5%, p = 0.01). Patients undergoing PMLVA showed a similar recurrence-free periods and overall survival when compared to the control group. Conclusions: PMLVA significantly reduces the frequency of SL both in immediate and delayed CLND. This procedure is safe and does not lead to an increase in length of hospitalization.

A survey of surgical management of the sentinel node positive melanoma patient in the post-MSLT2 era

BACKGROUND

The evidence-based management of melanoma patients with a positive sentinel lymph node biopsy (SLNB) has undergone a dramatic shift following publication of practice-changing surgical trials demonstrating no melanoma-specific survival advantage for completion lymph node dissection (CLND) in this scenario. We aimed to survey how surgeons' clinical practice had shifted in response to new evidence from these trials, and at a time when there was starting to become available systemic adjuvant treatments for AJCC Stage III melanoma patients.

METHODS

A web-based survey consisting of practice-based questions and hypothetical clinical scenarios about current melanoma practice with regard to positive sentinel node biopsy was developed and sent to the surgical members of a Melanoma and Skin Cancer (MASC) Trials group in December 2018. Responses were analysed using descriptive statistics.

RESULTS

There were 212 invitations sent and 65 respondents (31%). Respondents were from 17 countries, 94% of whom practice in specialist melanoma centres or at referral centres. Of these 97% were familiar with the MSLT2 and DeCOG-SLT clinical trials. At survey, 5% of respondents reported routinely recommending CLND and 55% recommend CLND in selected cases. Respondents were most likely to recommend CLND when multiple SLNs were positive. Important factors for surgical decision-making mentioned included size of SLN deposit, number of positive SLNs and likely compliance with the recommended surveillance regimen.

CONCLUSION

In line with rapid adoption of published evidence, surgical management of Stage III melanoma has altered significantly, with few surgeons within the cohort now performing routine CLNDs after positive SLNB.

Deep learning approach to predict sentinel lymph node status directly from routine histology of primary melanoma tumours

AIM

Sentinel lymph node status is a central prognostic factor for melanomas. However, the surgical excision involves some risks for affected patients. In this study, we therefore aimed to develop a digital biomarker that can predict lymph node metastasis non-invasively from digitised H&E slides of primary melanoma tumours.

METHODS

A total of 415 H&E slides from primary melanoma tumours with known sentinel node (SN) status from three German university hospitals and one private pathological practice were digitised (150 SN positive/265 SN negative). Two hundred ninety-one slides were used to train artificial neural networks (ANNs). The remaining 124 slides were used to test the ability of the ANNs to predict sentinel status. ANNs were trained and/or tested on data sets that were matched or not matched between SN-positive and SN-negative cases for patient age, ulceration, and tumour thickness, factors that are known to correlate with lymph node status.

RESULTS

The best accuracy was achieved by an ANN that was trained and tested on unmatched cases (61.8% ± 0.2%) area under the receiver operating characteristic (AUROC). In contrast, ANNs that were trained and/or tested on matched cases achieved (55.0% ± 3.5%) AUROC or less.

CONCLUSION

Our results indicate that the image classifier can predict lymph node status to some, albeit so far not clinically relevant, extent. It may do so by mostly detecting equivalents of factors on histological slides that are already known to correlate with lymph node status. Our results provide a basis for future research with larger data cohorts.

Prognostic Factors and Clinical Outcomes of Clinical Node-Negative Cutaneous Malignant Melanoma Patients: An Asian Single Institute Study

INTRODUCTION

Cutaneous malignant melanoma is notorious for its aggressive behavior and relatively poor outcome compared with other common skin malignancies. Acral lentiginous melanoma (ALM) accounts for at least 50% of melanoma in the Asian population and has a significantly lower survival rate. However, previous studies of the prognostic factors of melanoma-specific survival were all conducted from Western institutions. Here, we performed a retrospective analysis to investigate this issue.

METHODS

Fifty patients diagnosed as having clinical node-negative cutaneous malignant melanoma who underwent sentinel lymph node (SLN) biopsy at Taipei Veterans General Hospital between January 2007 and December 2018 were enrolled. Patient demographics, tumor characteristics, and lymph node characteristics were evaluated by chart review.

RESULTS

Eighty-two percent of the melanoma in the sample population was ALM. Twelve patients (24.0%) presented at least 1 metastatic sentinel node, and the average number of retrieved SLNs was 3. Of the patients with positive SLNs who proceeded to completion lymph node dissection, only 2 (16.7%) had metastatic nonsentinel nodes (NSNs). The average follow-up time for all patients was 45 months. Recurrence and melanoma-specific death occurred in 21 patients (42.0%) and 15 patients (30.0%), respectively. Melanoma-specific survival was significantly lower in patients with ulcerative lesions (P = 0.005) and more metastatic SLNs (P = 0.036). The overall morbidity rate of completion lymph node dissection was 66.7%.

CONCLUSIONS

The presence of ulcerations and number of metastatic SLNs were the most important prognostic factors in this ALM-dominant Asian cohort. Among patients with clinically negative nodes but positive SLNs, less than one-fourth of patients harbored metastatic NSNs. Completion lymph node dissection carries a relatively high risk of morbidity; therefore, further research regarding predictors of positive NSNs in the Asian population is necessary.

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.

Dissecting the immune landscape of tumor draining lymph nodes in melanoma with high-plex spatially resolved protein detection

BACKGROUND

In melanoma patients, microscopic tumor in the sentinel lymph-node biopsy (SLN) increases the risk of distant metastases, but the transition from tumor in the SLN to metastatic disease remains poorly understood.

METHODS

Fluorescent staining for CD3, CD20, CD11c, and DNA was performed on SLN tissue and matching primary tumors. Regions of interest (ROI) were then chosen geometrically (e.g., tumor) or by fluorescent cell subset markers (e.g., CD11c). Each ROI was further analyzed using NanoString Digital Spatial Profiling high-resolution multiplex profiling. Digital counts for 59-panel immune-related proteins were collected and normalized to account for system variation and ROI area.

RESULTS

Tumor regions of SLNs had variable infiltration of CD3 cells among patients. The patient with overall survival (OS) > 8 years had the most CD11c- and CD3-expressing cells infiltrating the SLN tumor region. All patients had CD11c (dendritic cell, DC) infiltration into the SLN tumor region. Selecting ROI by specific cell subtype, we compared protein expression of CD11c cells between tumor and non-tumor/normal tissue SLN regions. Known markers of DC activation such as CD86, HLA-DR, and OX40L were lowest on CD11c cells within SLN tumor for the patient with OS < 1 year and highest on the patient with OS > 8 years.

CONCLUSION

We demonstrate the feasibility of profiling the protein expression of CD11c cells within the SLN tumor. Identifying early regulators of melanoma control when the disease is microscopically detected in the SLN is beneficial and requires follow-up studies in a larger cohort of patients.

Stage IIIa Melanoma and Impact of Multiple Positive Lymph Nodes on Survival

BACKGROUND

For patients with cutaneous melanoma, having >1 positive lymph node (LN) is associated with worse survival. We hypothesized that for stage IIIA patients, N2a disease (2 to 3 positive LN) would be associated with a worse prognosis compared to those with N1a disease (1 positive LN).

STUDY DESIGN

Stage IIIA melanoma patients in the NCDB Participant User File from 2010 to 2016 were analyzed. Overall survival (OS) between N1a and N2a patients was compared. Subgroup analyses were made between patients undergoing sentinel lymph node (SLN) biopsy alone and those undergoing subsequent completion lymph node dissection (CLND). A separate post hoc analysis of T2a patients undergoing SLN biopsy and CLND from a prospective multicenter randomized clinical trial was performed to validate the findings.

RESULTS

Records of 2,305 IIIA patients were evaluated. In an adjusted survival model, N2a disease was an independent risk factor for worse OS (hazard ratio [HR] 1.56, p = 0.0052). In the subgroup analysis, there was no difference in OS between N1a and N2a disease for patients who underwent SLN biopsy without CLND (p = 0.59), but there was a significant difference in OS for patients who underwent SLN biopsy plus CLND (p = 0.0009). The separate clinical trial database confirmed that for patients with SLN-only disease, there was no difference in OS between N1a and N2a disease.

CONCLUSIONS

For stage IIIA melanoma patients, the distribution of micrometastatic lymph node disease (SLN or non-SLN), rather than the absolute number of SLNs, should be considered when individualizing adjuvant therapy recommendations.

The PD-1/PD-L1-Checkpoint Restrains T cell Immunity in Tumor-Draining Lymph Nodes

PD-1/PD-L1-checkpoint blockade therapy is generally thought to relieve tumor cell-mediated suppression in the tumor microenvironment but PD-L1 is also expressed on non-tumor macrophages and conventional dendritic cells (cDCs). Here we show in mouse tumor models that tumor-draining lymph nodes (TDLNs) are enriched for tumor-specific PD-1⁺ T cells which closely associate with PD-L1⁺ cDCs. TDLN-targeted PD-L1-blockade induces enhanced anti-tumor T cell immunity by seeding the tumor site with progenitor-exhausted T cells, resulting in improved tumor control. Moreover, we show that abundant PD-1/PD-L1-interactions in TDLNs of nonmetastatic melanoma patients, but not those in corresponding tumors, associate with early distant disease recurrence. These findings point at a critical role for PD-L1 expression in TDLNs in governing systemic anti-tumor immunity, identifying high-risk patient groups amendable to adjuvant PD-1/PD-L1-blockade therapy.

Development and validation of a Brazilian nomogram to assess sentinel node biopsy positivity in melanoma

BACKGROUND

Although well-established, sentinel node biopsy (SNB) for melanoma is not free from controversies and sometimes it can be questionable if SNB should be considered even for patients who meet the criteria for the procedure. Mathematical tools such as nomograms can be helpful and give more precise answers for both clinicians and patients. We present a nomogram for SNB positivity that has been internally validated.

METHODS

Retrospective analysis of patients who underwent SNB from 2000 to 2015 in a single institution. Single logistic regressions were used to identify variables that were associated to SNB positivity. All variables with a p value < 0.05 were included in the final model. Overall performance, calibration, and discriminatory power of the final multiple logistic regression model were all assessed. Internal validation of the multiple logistic regression model was performed via bootstrap analysis based on 1000 replications.

RESULTS

Site of primary lesion, Breslow thickness, mitotic rate, histologic regression, lymphatic invasion, and Clark level were statistically related to SNB positivity. After internal validation, a good performance was observed as well as an adequate power of discrimination (area under the curve 0.751).

CONCLUSIONS

We have presented a nomogram that can be helpful and easily used in daily practice for assessing SNB positivity.

Completely resected stage III melanoma controversy - 15 years of national tertiary centre experience

BACKGROUND

Two prospective randomized studies analysing cutaneous melanoma (CM) patients with sentinel lymph node (SLN) metastases and rapid development of systemic adjuvant therapy have changed our approach to stage III CM treatment. The aim of this study was to compare results of retrospective survival analysis of stage III CM patients' treatment from Slovenian national CM register to leading international clinical guidelines.

PATIENTS AND METHODS

Since 2000, all Slovenian CM patients with primary tumour ≥ TIb are treated at the Institute of Oncology Ljubljana and data are prospectively collected into a national CM registry. A retrospective analysis of 2426 sentinel lymph node (SLN) biopsies and 789 lymphadenectomies performed until 2015 was conducted using Kaplan-Meier survival curves and log-rank tests.

RESULTS

Positive SLN was found in 519/2426 (21.4%) of patients and completion dissection (CLND) was performed in 455 patients. The 5-year overall survival (OS) of CLND group was 58% vs. 47% of metachronous metastases group (MLNM) (p = 0.003). The 5-year OS of patients with lymph node (LN) metastases and unknown primary site (UPM) was 45% vs. 21% of patients with synchronous LN metastasis. Patients with SLN tumour burden < 0.3 mm had 5-year OS similar to SLN negative patients (86% vs. 85%; p = 0.926). The 5-year OS of patients with burden > 1.0 mm was similar to the MLNM group (49% vs. 47%; p = 0.280).

CONCLUSIONS

Stage III melanoma patients is a heterogeneous group with significant OS differences. CLND after positive SLNB might still remain a method of treatment for selected patients with stage III.

Management of the positive sentinel lymph node in the post-MSLT-II era

BACKGROUND AND OBJECTIVES

The publication of MSLT-II shifted recommendations for management of sentinel lymph node biopsy positive (SLNB+) melanoma to favor active surveillance. We examined trends in immediate completion lymph node dissection (CLND) following publication of MSLT-II.

METHODS

Using a prospective melanoma database at a high-volume center, we identified a cohort of consecutive SLNB+ patients from July 2016 to April 2019. Patient and disease characteristics were analyzed with multivariate logistic regression to examine factors associated with CLND.

RESULTS

Two hundred and thirty-five patients were included for analysis. CLND rates were 67%, 33%, and 26% for the year before, year after, and second-year following MSLT-II. Factors associated with undergoing CLND included primary located in the head and neck (59% vs 33%, P = .003 and odds ratio [OR], 5.22, P = .002) and higher sentinel node tumor burden (43% vs 10% for tumor burden ≥0.1 mm, P < .001 and OR, 8.64, P = .002).

CONCLUSIONS

Rates of CLND in SLNB+ melanoma decreased dramatically, albeit not uniformly, following MSLT-II. Factors that increased the likelihood of immediate CLND were primary tumor located in the head and neck and high sentinel node tumor burden. These groups were underrepresented in MSLT-II, suggesting that clinicians are wary of implementing active surveillance recommendations for patients perceived as higher risk.

Safety of pembrolizumab for resected stage III melanoma

INTRODUCTION

Patients with resected stage III melanoma have a heterogeneous prognosis with an especially high risk of relapse for patients with stage IIIB, IIIC and IIID according to the 2018 classification in AJCC Cancer Staging Manual, 8^th edition (AJCC-8). Ipilimumab was the first immune checkpoint inhibitor (ICI) to show prolonged overall survival (OS) but at the cost of high toxicity. Pembrolizumab and nivolumab are inhibitors of programmed cell death 1 (PD-1) and showed prolonged relapse-free survival (RFS) in patients with resected stage III melanoma at high risk of relapse compared to placebo and ipilimumab, respectively.

AREAS COVERED

The aim of this article is to review the mechanisms of action, pharmacokinetics and safety data of pembrolizumab in resected stage III melanoma and to compare its safety profile to other immune checkpoint inhibitors for the same indication.

EXPERT OPINION

Pembrolizumab as adjuvant therapy of resected stage III melanoma showed an acceptable safety profile, which is comparable to that in advanced melanoma. However, it caused one death. There is uncertainty about its benefits in AJCC-8 stage IIIA melanoma patients. Additionally, caution is required since OS and long-term safety data are not available yet.

Updates in the evidence-based management of cutaneous melanoma

Treatment of cutaneous melanoma is changing with significant developments over the past several years that promise to reshape the field of melanoma surgical oncology. Modifications to the staging system based on analysis of a large international dataset, the timing and extent of regional lymphadenectomy, the emergence of effective systemic therapies in the neoadjuvant and adjuvant setting, and the role of adjuvant radiation are all undergoing a data-driven evolution. Surgeon engagement in multidisciplinary decision making remains an essential component of contemporary management for patients across all stages of melanoma and demands specific involvement of head and neck surgical oncologists.

Sentinel Node Status is the Most Important Prognostic Information for Clinical Stage IIB and IIC Melanoma Patients

BACKGROUND

Sentinel node biopsy (SNB) for melanoma patients has been questioned. We aimed to study high-risk stage II melanoma patients who underwent SNB to determine what the prognostic factors regarding recurrence and mortality were, and evaluate how relevant SNB status is in this scenario.

METHODS

This was a retrospective analysis of clinical stage IIB/IIC melanoma patients who underwent SNB from 2000 to 2015 in a single institution. Prognostic factors related to distant recurrence-free survival (DRFS) and melanoma-specific survival (MSS) were assessed from multiple Cox regression. Relevant variables were used to create risk predictor nomograms for DRFS and MSS.

RESULTS

From 1213 SNB, 259 were performed for clinical stage IIB/IIC melanoma patients. SNB status was the most important variable for both endpoints. Patients with positive SNB presented median DRFS of 35.73 months (95% CI 21.38-50.08, SE 7.32) and median MSS of 66.4 months (95% CI 29.76-103.03, SE 18.69), meanwhile both median DRFS and MSS were not achieved for those with negative SNB (logrank < 0.0001). Both nomograms have been internally validated and presented adequate calibration (C-index was 0.734 for DRFS and 0.718 for MSS).

CONCLUSIONS

SNB status was the most important risk factor in our cohort of clinical stage IIB and IIC patients and, in conjunction with well-established primary tumor characteristics, should not be abandoned. Their use in prognosis for these patients remains extremely useful for daily practice.

ESMO consensus conference recommendations on the management of locoregional melanoma: under the auspices of the ESMO Guidelines Committee

The European Society for Medical Oncology (ESMO) held a consensus conference on melanoma on 5-7 September 2019 in Amsterdam, The Netherlands. The conference included a multidisciplinary panel of 32 leading experts in the management of melanoma. The aim of the conference was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where available evidence is either limited or conflicting. The main topics identified for discussion were: (i) the management of locoregional disease; (ii) targeted versus immunotherapies in the adjuvant setting; (iii) targeted versus immunotherapies for the first-line treatment of metastatic melanoma; (iv) when to stop immunotherapy or targeted therapy in the metastatic setting; and (v) systemic versus local treatment of brain metastases. The expert panel was divided into five working groups in order to each address questions relating to one of the five topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the results relating to the management of locoregional melanoma, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

The extent of surgery for stage III melanoma: how much is appropriate?

Since the first documented lymph node dissection in 1892, many trials have investigated the potential effect of this surgical procedure on survival in patients with melanoma. Two randomised controlled trials were unable to demonstrate improved survival with completion lymph node dissection versus nodal observation in patients with sentinel node-positive disease, although patients with larger sentinel node metastases (>1 mm) might benefit more from observation than from dissection, and could potentially be considered for adjuvant systemic therapy instead of complete dissection. Adjuvant immunotherapy with high-dose ipilimumab has led to improvements in overall survival, whereas therapy with nivolumab and pembrolizumab has improved relapse-free survival with greater safety. Furthermore, adjuvant-targeted therapy with dabrafenib and trametinib has improved survival outcomes in BRAF^V600E and BRAF^V600K-mutated melanomas. Three neoadjuvant trials have all shown high response rates, including complete responses, after short-term combination therapy with ipilimumab and nivolumab with no recurrences so far, although follow-up is still short. Despite the absence of a survival benefit with completion lymph node dissection in patients with sentinel node-positive or negative disease, the use of sentinel node staging will increase because of the introduction of effective adjuvant therapies. However, routine completion lymph node dissection for sentinel node-positive disease should be reconsidered. Accordingly, existing clinical guidelines are currently being revised. For palpable (macroscopic) nodal disease, the type and extent of surgery could be reduced if the index node can accurately predict the response and if studies show that lymph node dissection can be safely foregone in patients with a complete response. Overall, the appropriate type and extent of surgery for stage III melanoma is changing and becoming more personalised.

Adjuvant systemic therapy in high-risk melanoma

In resected high-risk melanoma (stage IIB/C-III) the risk of locoregional and/or distant recurrence is substantial and so far adjuvant therapies have been fairly unsuccessful. Interferon showed slight improvements in recurrence-free survival (RFS) but failed to convincingly improve overall survival (OS). In these patients, adjuvant therapy with treatments that show promising results in stage IV disease is arising. Studies using immune checkpoint blockade with anti-CTLA-4 and anti-PD-1 agents reveal convincing RFS benefits. OS rates, however, are not mature yet in most studies. Only ipilimumab has shown an OS benefit but at a high cost of toxicity. Also in studies with adjuvant targeted therapy using BRAF and MEK inhibitors, ensuring results are reported regarding RFS. As possible toxicity cannot be ignored, it is crucial to identify patients who would benefit most from these adjuvant therapies. In patients with clinically detectable lymph node metastases, studies using neoadjuvant schedules of immunotherapy and targeted therapy have been performed. In phase I and II studies the most optimal schedule of combination immunotherapy was identified and further research on this front will follow in the coming years. Concluding, after decades of scarce options for patients with high-risk melanoma, recent developments in adjuvant therapy have changed the standard of care for these patients.

The EORTC-DeCOG nomogram adequately predicts outcomes of patients with sentinel node-positive melanoma without the need for completion lymph node dissection

PURPOSE

Based on recent advances in the management of patients with sentinel node (SN)-positive melanoma, we aimed to develop prediction models for recurrence, distant metastasis (DM) and overall mortality (OM).

METHODS

The derivation cohort consisted of 1080 patients with SN-positive melanoma from nine European Organization for Research and Treatment of Cancer (EORTC) centres. Prognostic factors for recurrence, DM and OM were studied with Cox regression analysis. Significant factors were incorporated in the models. Performance was assessed by discrimination (c-index) and calibration in cross-validation across centres. The models were externally validated using a prospective cohort consisting of 705 German patients with SN-positive: 473 trial participants of the German Dermatologic Cooperative Oncology Group study (DeCOG-SLT) and 232 screened patients. A nomogram was developed for graphical presentation.

RESULTS

The final model for recurrence and the calibrated models for DM and OM included ulceration, age, SN tumour burden and Breslow thickness. The models showed reasonable calibration. The c-index for the recurrence, DM and OM model was 0.68, 0.70 and 0.70, respectively, and 0.70, 0.72 and 0.74, respectively, in external validation. The EORTC-DeCOG model identified a robust low-risk group, with all identified low-risk patients (approximately 4% of the entire population) having a 5-year recurrence probability of <25% and an overall 5-year recurrence rate of 13%. A model including information on completion lymph node dissection (CLND) showed only marginal improvement in model performance.

CONCLUSIONS

The EORTC-DeCOG nomogram provides an adequate prognostic tool for patients with SN-positive melanoma, without the need for CLND. It showed consistent results across validation. The nomogram could be used for patient counselling and might aid in adjuvant therapy decision-making.

Treatment of Advanced Melanoma in 2020 and Beyond

The melanoma field has seen an unprecedented set of clinical advances over the past decade. Therapeutic efficacy for advanced or metastatic melanoma went from being one of the most poorly responsive to one of the more responsive. Perhaps most strikingly, the advances that transformed management of the disease are based upon modern mechanism-based therapeutic strategies. The targeted approaches that primarily suppress the BRAF oncoprotein pathway have a high predictability of efficacy although less optimal depth or durability of response. Immunotherapy is primarily based on blockade of one or two immune checkpoints and has a lower predictability of response but higher fractions of durable remissions. This article reviews the clinical progress in management of advanced melanoma and also discusses the impact of the same therapies on earlier stage disease, where the agents have shown significant promise in treating resectable but high-risk clinical scenarios. Collectively, the progress in melanoma therapeutics has transformed the standard of care for patients, informed new approaches that are increasingly utilized for treatment of other malignancies, and suggest novel strategies to further boost efficacy for the many patients not yet receiving optimal benefit from these approaches.

Sentinel node tumor burden in prediction of prognosis in melanoma patients

Recent data have demonstrated no survival benefit to immediate completion lymph node dissection (CLND) for positive sentinel node (SN) disease in melanoma. It is important to identify parameters in positive SNs, which predict prognosis in melanoma patients. These might provide prognostic value in staging systems and risk models by guiding high-risk patients’ adjuvant therapy in clinical practice. In this retrospective study of university hospital melanoma database we analyzed tumor burden and prognosis in patients with positive SNs. Patients were stratified by the diameter of tumor deposit, distribution of metastatic focus in SN, ulceration and number of metastatic SNs. These were incorporated in Cox proportional hazard regression models. Predictive ability was assessed using Akaike information criterion and Harrell’s concordance index. A total of 110 patients had positive SN and 104 underwent CLND. Twenty-two (21%) patients had non-SN metastatic disease on CLND. The 5-year melanoma specific survival for CLND-negative patients was 5.00 years (IQR 3.23–5.00, range 0.72–5.00) compared to 3.69 (IQR 2.28–4.72, range 1.01–5.00) years in CLND-positive patients (HR 2.82 (95% CI 1.17–6.76, p = 0.020).The models incorporating distribution of metastatic focus and the largest tumor deposit in SN had highest predictive ability. According to Cox proportional hazard regression models, information criterions and c-index, the diameter of tumor deposit > 4 mm with multifocal location in SN despite of number of metastatic SN were the most important parameters. According to the diameter of tumor deposit and distribution of metastatic focus in SN, adequate stratification of positive SN patients was possible and risk classes for patients were identified.

The Predictive Approaches to Treatment effect Heterogeneity (PATH) Statement: Explanation and Elaboration

The PATH (Predictive Approaches to Treatment effect Heterogeneity) Statement was developed to promote the conduct of, and provide guidance for, predictive analyses of heterogeneity of treatment effects (HTE) in clinical trials. The goal of predictive HTE analysis is to provide patient-centered estimates of outcome risk with versus without the intervention, taking into account all relevant patient attributes simultaneously, to support more personalized clinical decision making than can be made on the basis of only an overall average treatment effect. The authors distinguished 2 categories of predictive HTE approaches (a "risk-modeling" and an "effect-modeling" approach) and developed 4 sets of guidance statements: criteria to determine when risk-modeling approaches are likely to identify clinically meaningful HTE, methodological aspects of risk-modeling methods, considerations for translation to clinical practice, and considerations and caveats in the use of effect-modeling approaches. They discuss limitations of these methods and enumerate research priorities for advancing methods designed to generate more personalized evidence. This explanation and elaboration document describes the intent and rationale of each recommendation and discusses related analytic considerations, caveats, and reservations.

Correlation of Tumor Burden in Sentinel Lymph Nodes with Tumor Burden in Nonsentinel Lymph Nodes and Survival in Cutaneous Melanoma

PURPOSE

In patients with cutaneous melanoma, metastasis in a nonsentinel lymph node (non-SLN) is a strong independent adverse prognostic factor. However, patients with a tumor-involved SLN no longer routinely undergo completion lymph node dissection (CLND). We hypothesized that SLN tumor burden may predict non-SLN tumor burden.

EXPERIMENTAL DESIGN

We compared tumor burden parameters between SLN and non-SLN in patients with cutaneous melanoma who underwent SLN biopsy with a positive SLN during 2003 to 2008 at The University of Texas MD Anderson Cancer Center.

RESULTS

We identified 336 eligible patients with a positive SLN. Of these, 308 (92%) underwent CLND, and 35 (10%) had non-SLN metastasis. The median follow-up time was 6.0 years. For patients with maximum diameter of tumor in the SLN ≤2.0 mm, >2.0-5.0 mm, and >5.0 mm, non-SLN metastasis was detected in 5 of 200 patients (3%), 10 of 63 patients (16%), and 20 of 57 patients (35%), and the mean maximum diameters of the non-SLN tumor deposits were 0.09, 1.56, and 2.71 mm, respectively (P < 0.0001). The percentage of patients with both subcapsular and intraparenchymal non-SLN tumor was higher for patients with SLN tumor in both locations than for patients with SLN tumor in only one location (P < 0.0001). Extranodal extension in a non-SLN was more common in patients with extranodal extension in an SLN (P = 0.003).

CONCLUSIONS

In patients with cutaneous melanoma who undergo CLND, SLN tumor burden predicts non-SLN tumor burden. SLN tumor burden parameters provide accurate prognostic stratification independent of non-SLN status and should be considered for incorporation into future staging systems and integrated risk models.

Desmoplastic melanoma: The role of pure and mixed subtype in sentinel lymph node biopsy and survival

Background

Desmoplastic melanoma (DM) is an uncommon type of melanoma. Two histological subtypes of DM can be distinguished: pure and mixed (PDM and MDM). We hypothesized that discrimination between these subtypes is associated with sentinel lymph node biopsy (SLNB) status and survival.

Methods

Clinicopathological data from PALGA, the Dutch Pathology Register were retrieved from patients diagnosed with DM in The Netherlands between 2000 and 2014. Clinical and pathological variables were extracted from pathology text files, including pure or mixed desmoplastic morphology. A Cox proportional hazard model was performed for overall and recurrence‐free survival (OS and RFS).

Results

A total of 239 patients with DM were included, representing 0.4% of all primary cutaneous melanoma in The Netherlands. A total of 114 PDM and 125 MDM patients were identified. MDM was significantly associated with positive SLNB status (P = .035). In multivariable analysis, age (HR 1.10, 95% CI 1.07‐1.14, P < .001) and ulceration (HR 1.98, 95% CI 1.05‐3.75, P = .036) were significant predictors for OS. For RFS, mixed subtype (HR 2.72 95% CI 1.07‐6.89, P = .035), male gender (HR 2.54, 95% CI 1.03‐6.27, P = .043), and Breslow thickness (HR 1.13 per mm, 95% CI 1.05‐1.21, P = .001) were significant predictors.

Conclusion

MDM is significantly associated with a positive SLNB status. Mixed subtype is significantly correlated with RFS, but not with OS. The distinction between pure and mixed desmoplastic subtype therefore seems to be of clinical importance.

Adjuvant Treatment of Melanoma: Recent Developments and Future Perspectives

Surgical excision is the treatment of choice for early stage melanoma, and this strategy is initially curative for the vast majority of patients. However, only approximately 40-60% of high-risk patients who undergo surgery alone will be disease-free at 5 years. These patients will ultimately experience loco-regional relapse or relapse at distant sites. The main aim of adjuvant therapies is to reduce the recurrence rate of radically operated patients at high risk and to potentially improve survival. Recent practice changing results with immune checkpoint inhibitors and targeted therapies have been published in stage III/IV melanoma patients, after surgical complete resection, and have dramatically improved the landscape of adjuvant therapy. Interferon-α, ipilimumab, and more recently anti-programmed cell death protein-1 antibodies and BRAF inhibitors plus MEK inhibitors have been approved in the adjuvant setting by the US Food and Drug Administration; similarly, the same drugs are approved by the European Medicines Agency with the exception of ipilimumab. A completely new scenario is emerging in the neoadjuvant setting as well: in locally advanced or metastatic disease, patients may partially respond to neoadjuvant therapy and become virtually resectable with systemic control of disease. This review summarizes the current state of the field and describes new strategies tracing the history of adjuvant therapy in melanoma, with a view on future projects.

Nonsurgical Management of Lymph Node Basins in Melanoma

In this article we provide a critical review of the evidence available for surgical management of the nodal basin in melanoma, with an aim to ensure an understanding of risks and benefits for all lymph node surgery offered to patients, and alternatives to surgical management where appropriate.

Current management of patients with melanoma who are found to be sentinel node-positive

Background

The results of the DeCOG‐SLT and MSLT‐II studies, published in 2016 and mid‐2017, indicated no survival benefit from completion lymph node dissection (CLND) in melanoma patients with positive sentinel nodes (SNs). Subsequently, several studies have been published reporting a benefit of adjuvant systemic therapy in patients with stage III melanoma. The current study assessed how these findings influenced management of SN‐positive patients in a dedicated melanoma treatment centre.

Methods

SN‐positive patients treated at Melanoma Institute Australia between July 2017 and December 2018 were prospectively identified. Surgeons completed a questionnaire documenting the management of each patient. Information on patients, primary tumours, SNs, further treatment and follow‐up was collected from patient files, the institutional research database and pathology reports.

Results

During the 18‐month study period, 483 patients underwent SN biopsy. A positive SN was found in 61 (13%). Two patients (3%) requested CLND because of anxiety about observation in view of unfavourable primary tumour and SN characteristics. The other 59 patients (97%) were followed with a four‐monthly ultrasound examination of the relevant lymph node field(s). Two of them (3%) developed an isolated nodal recurrence after 4 and 11 months of follow‐up. Fifty‐seven patients (93%) were seen following the publication of the first two adjuvant systemic therapy studies in November 2017; 46 (81%) were referred to a medical oncologist to discuss adjuvant systemic therapy, which 32 (70%) chose to receive.

Conclusion

At Melanoma Institute Australia most patients with an involved SN are now managed without CLND. The majority are referred to a medical oncologist and receive adjuvant systemic therapy.

An evidence-based approach to positive sentinel node disease: should we ever do a completion node dissection?

Management of later stage melanoma has undergone significant changes. Sentinel node biopsy has long been an accepted method of staging, but two recent randomized-controlled trials have provided an evidence base for decision making about completion lymphadenectomy. They showed no survival advantage in further surgery for patients with positive sentinel node biopsies. There is now no evidence to support completion lymphadenectomy in the majority of patients, and this is reflected in international practice guidelines.

The adjuvant treatment revolution for high-risk melanoma patients

The past 5 years have witnessed the results of many practice-changing studies that have dramatically improved the landscape of adjuvant therapy in patients with resected, high-risk melanoma. After a 20-year era of adjuvant interferon, the anti-CTLA-4 and anti-PD-1 immune-checkpoint inhibitors, and MAPK-directed targeted therapy brought a revolution into the adjuvant treatment of melanoma. These results came along with the practice-changing results of two large multicenter studies showing no benefit in terms of overall survival for completion lymph node dissection after positive sentinel node biopsy. In this review, we summarized the current state of the art of the adjuvant treatment of high-risk melanoma, with a view on future perspectives.

New paradigm for stage III melanoma: from surgery to adjuvant treatment

Background

Recently the 8th version of the American Joint Committee on Cancer (AJCC) classification has been introduced, and has attempted to define a more accurate and precise definition of prognosis in line with the major progresses in understanding the biology and pathogenesis of melanoma. This new staging system introduces major changes in the stage III staging system. Indeed, surgical practice is changing in stage III patients, since, according to recent evidence, there is no survival benefit in radical lymph node dissection following a positive sentinel lymph node dissection. Therefore, some patients currently staged IIIB-C after dissection could be downgraded to IIIA (as in the case of patients with metastatic non-sentinel lymph nodes) since many completion lymph node dissections will no longer be performed. Moreover, new and effective targeted and immune strategies are being introduced in the pharmacological armamentarium in the adjuvant setting, showing major efficacy.

Conclusions

This article provides the authors’ personal view on the above-mentioned topics.

Comparison of seventh and eighth edition of AJCC staging system in melanomas at locoregional stage

Background

The eighth edition of the American Joint Committee on Cancer (AJCC) staging system has been effective since January 2018. It has introduced some major changes in the localized/locoregional melanoma classification. However, it has not been demonstrated how this classification was validated on external, clinical data.

Patients and methods

In this retrospective study, we have included 2474 patients diagnosed with cutaneous melanoma in localized or locoregional stage. They were treated surgically in our Center between years 1998 and 2014. Melanoma-specific and overall survival were calculated for each stage according to TNM7 and TNM8 using Kaplan-Meier estimator.

Results

The melanoma-specific survival rates in our patients were similar to those reported from original cohort used to build TNM8 classification except for stage IIIC (5-year melanoma-specific survival 44.6% vs 51.8%, respectively for TNM7 vs TNM8).

Conclusion

Our study validated the eighth edition of TNM melanoma staging system as a viable tool in prognosis of the long-term survival of patients with localized or locoregionally advanced melanoma on an independent cohort. The new TNM 8 system has brought important improvements in prognostic assessment for melanoma patients. Deeper understanding of the significance of satellite/in-transit lesions may be required.

Electronic supplementary material

The online version of this article (10.1186/s12957-019-1669-6) contains supplementary material, which is available to authorized users.

Prognostic and predictive value of AJCC-8 staging in the phase III EORTC1325/KEYNOTE-054 trial of pembrolizumab vs placebo in resected high-risk stage III melanoma

BACKGROUND

The American Joint Committee on Cancer-8 (AJCC) classification of melanoma was implemented in January 2018. It was based on data gathered when checkpoint inhibitors were not used as adjuvant therapy in stage III melanoma. The European Organization for Research and Treatment of Cancer (EORTC) 1325/KEYNOTE-054 double-blind phase III trial evaluated pembrolizumab vs placebo in AJCC-7 stage IIIA (excluding lymph node metastasis ≤1 mm), IIIB or IIIC (without in-transit metastasis) patients after complete lymphadenectomy.

PATIENTS, METHODS AND RESULTS

Patients (n = 1019) were randomised 1:1 to pembrolizumab 200 mg or placebo every 3 weeks (total of 18 doses, ∼1 year). At 1.25-year median follow-up, pembrolizumab prolonged relapse-free survival (RFS) in the total population (1-year RFS rate: 75.4% vs 61.0%; hazard ratio [HR] 0.57; logrank P < 0.0001) and consistently in the AJCC-7 subgroups. Prognostic and predictive values of AJCC-8 for RFS were evaluated in this study. Patient distribution according to the AJCC-8 stage subgroups was 8% (IIIA), 34.7% (IIIB), 49.7% (IIIC), 3.7% (IIID) and 3.8% (unknown). AJCC-8 classification was strongly associated with RFS (HRs for stage IIIB, IIIC and IIID vs IIIA were 4.0, 5.7 and 12.2, respectively) but showed no predictive importance for the treatment comparison regarding RFS (test for interaction: P = 0.68). The 1-year RFS rate for pembrolizumab vs placebo and the HRs (99% confidence interval) within each AJCC-8 subgroup were as follows: stage IIIA (92.7% vs 92.5%; 0.76 [0.11-5.43]), IIIB (79.0% vs 65.5%; 0.59 [0.35-0.99]), IIIC (73.6% vs 53.9%; 0.48 [0.33-0.70]) and IIID (50.0% vs 33.3%; 0.69 [0.24-2.00]).

CONCLUSIONS

AJCC-8 staging had a strong prognostic importance for RFS but no predictive importance: the RFS benefit of pembrolizumab was observed across AJCC-8 subgroups in resected high-risk stage III melanoma patients.

Rational combination of cancer immunotherapy in melanoma

The recent advances in cancer immunotherapy with unprecedented success in therapy of advanced melanoma represent a turning point in the landscape of melanoma treatment. Given the complexity of activation of immunological system and the physiologic multifactorial homeostatic mechanisms controlling immune responses, combinatorial strategies are eagerly needed in melanoma therapy. Nevertheless, rational selection of immunotherapy combinations should be more biomarker-guided, including not only the cancer immunogram, PD-L1 expression, interferon gene expression signature, mutational burden, and tumor infiltration by CD8+ T cells but also intratumoral T cell exhaustion and microbiota composition. In this review, we summarize the rationale to develop combination treatment strategies in melanoma and discuss biological background that could help to design new combinations in order to improve patients' outcome.