Nonsentinel lymph node status in patients with cutaneous melanoma: results from a multi-institution prognostic study

Impact of extra-nodal extension and AJCC lymph node staging in predicting recurrence following lymphadenectomy in patients with melanoma

BACKGROUND

Regional lymphadenectomy (RL) has traditionally been recommended in patients with melanoma found to have clinical lymphadenopathy or a positive sentinel lymph node biopsy (SLNB). Regional control of disease is still a relevant issue for patients, even after undergoing lymphadenectomy. The goal of this study was to identify the clinicopathologic characteristics that predict locoregional recurrence in patients who have undergone either therapeutic lymph node dissection (TLND) or completion lymph node dissection (CLND) following SLNB.

METHODS

Retrospective review of population-based cohort of patients with melanoma lymph node metastasis from the years 2005-2015. Multivariate, proportional hazards regression analysis was performed to determine factors predicting nodal recurrence.

RESULTS

586 patients underwent a RL, with a median follow up of 35 months. Overall, in-basin recurrence rates in the axilla, groin, and head/neck were 7.7 ​%, 8.7 ​% and 9.2 ​%, respectively. Higher unadjusted recurrence rates occurred following CLND than TLND of the groin (12.8 ​% vs 4.5 ​%) and neck (10.0 ​% vs 4.7 ​%) but not the axilla (7.5 ​% vs 8.0 ​%). Upon multivariate analysis, ENE (HR 2.77; p=<0.0001) and the AJCC lymph node stage (N3 vs N1) (HR 2.51; p ​= ​0.025) were predictive of regional recurrence.

CONCLUSION

The AJCC nodal stage and the presence of extranodal extension were the only variables impacting regional recurrence following regional lymphadenectomy for melanoma. When considering regional disease control, they should be factored into treatment decisions, and surveillance strategies.

Lymphadenectomy After Melanoma-A National Analysis of Recurrence Rates and Risk of Lymphedema

INTRODUCTION

Treatment for melanoma after a positive sentinel lymph node biopsy includes nodal observation or lymphadenectomy. Important considerations for management, however, involve balancing the risk of recurrence and the risk of lymphedema after lymphadenectomy.

METHODS

From the Merative MarketScan Research Databases, adult patients were queried from 2007 to 2021. International Classification of Disease, Ninth (ICD-9) and Tenth (ICD-10) Editions, diagnosis codes and Current Procedural Terminology codes were used to identify patients with melanoma diagnoses who underwent an index melanoma excision with a positive sentinel lymph node biopsy (SLNB). Main outcomes were completion lymph node dissection (CLND) utilization after a positive SLNB, developing lymphedema with or without CLND, and nodal basin recurrence 3 months or more after index excision. Subanalyses stratified by index excision year (2007-2017 and 2018-2021) and propensity score matched were additionally conducted. Demographics and comorbidities (measured by Elixhauser index) were recorded.

RESULTS

A total of 153,085,453 patients were identified. Of those, 359,298 had a diagnosis of melanoma, and 202,456 patients underwent an excision procedure. The study cohort comprised 3717 patients with a melanoma diagnosis who underwent an excision procedure and had a positive SLNB. The mean age of the study cohort was 49 years, 57% were male, 41% were geographically located in the South, and 24% had an Elixhauser index of 4+. Among the 350 patients who did not undergo CLND, 10% experienced recurrence and 22% developed lymphedema. A total of 3367 patients underwent CLND, of which 8% experienced recurrence and 20% developed lymphedema. Completion lymph node dissection did not significantly affect risk of recurrence [odds ratio (OR), 1.370, P = 0.090] or lymphedema (OR, 1.114, P = 0.438). After stratification and propensity score matching, odds of experiencing lymphedema (OR, 1.604, P = 0.058) and recurrence (OR, 1.825, P = 0.058) after CLND were not significantly affected. Rates of CLND had significantly decreased (P < 0.001) overtime, without change in recurrence rate (P = 0.063).

CONCLUSIONS

Electing for nodal observation does not increase the risk of recurrence or reduce risk of lymphedema. Just as CLND does not confer survival benefit, its decreased utilization has not increased recurrence rate.

Surgical Management of Melanoma: Advances and Updates

PURPOSE OF REVIEW

To review and update surgeons about the evolving complexities in the surgical management of melanoma including lymph node staging and treatment.

RECENT FINDINGS

Primary resection with adequate margins continues to be the standard of care for localized cutaneous melanoma. Sentinel lymph node biopsy is confirmed to be a powerful tool due to its prognostic value and informative guidance for adjuvant treatments and surveillance. Due to the lack of benefit in melanoma-specific survival and distant metastasis-free survival, completion lymph node dissection is not performed routinely after a positive sentinel lymph node biopsy. Neoadjuvant systemic treatment approaches for advanced loco-regional disease show promise in phase I and II clinical trial data, and phase III studies. The surgical management of cutaneous melanoma continues to evolve with further de-escalation of the extent of excision of primary melanomas and the management of lymph node disease.

Predictors of Nodal Metastasis in Cutaneous Head and Neck Cancers

PURPOSE OF REVIEW

The complex and varied drainage patterns in the head and neck present a challenge in the regional control of cutaneous neoplasms. Lymph node involvement significantly diminishes survival, often warranting more aggressive treatment. Here, we review the risk factors associated with lymphatic metastasis, in the context of the evolving role of sentinel lymph node biopsy.

RECENT FINDINGS

In cutaneous head and neck melanomas, tumor thickness, age, size, mitosis, ulceration, and specific histology have been associated with lymph node metastasis (LNM). In head and neck cutaneous squamous cell carcinomas, tumor thickness, size, perineural invasion, and immunosuppression are all risk factors for nodal metastasis. The risk factors for lymph node involvement in Merkel cell carcinoma are not yet fully defined, but emerging evidence indicates that tumor thickness and size may be  associated with regional metastasis. The specific factors that predict a greater risk of LNM for cutaneous head and neck cancers generally include depth of invasion, tumor size, mitotic rate, ulceration, immunosuppression, and other histopathological factors.

Management of Regional Nodal Melanoma

Regional nodal melanoma management has changed substantially over the past 2 decades alongside advances in systemic therapy. Significant data from retrospective studies and from 2 randomized controlled trials show no survival benefit to completion lymph node dissection compared with observation in sentinel lymph node-positive melanoma patients. Observation is becoming the standard recommendation in these patients, whereas patients with clinically detected lymph nodes are still recommended to undergo lymph node dissection. Promising early results from a neoadjuvant approach inform the ongoing evolution of melanoma management. Recruiting patients to clinical trials is paramount to attaining evidence-based practice changes in melanoma.

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.

Prognostic and Predictive Biomarkers in Stage III Melanoma: Current Insights and Clinical Implications

Melanoma is one of the most aggressive skin cancers. The 5-year survival rate of stage III melanoma patients ranges from 93% (IIIA) to 32% (IIID) with a high risk of recurrence after complete surgery. The introduction of target and immune therapies has dramatically improved the overall survival, but the identification of patients with a high risk of relapse who will benefit from adjuvant therapy and the determination of the best treatment choice remain crucial. Currently, patient prognosis is based on clinico-pathological features, highlighting the urgent need of predictive and prognostic markers to improve patient management. In recent years, many groups have focused their attention on identifying molecular biomarkers with prognostic and predictive potential. In this review, we examined the main candidate biomarkers reported in the literature.

Recent Evolution in the Management of Lymph Node Metastases in Melanoma

Introduction

Based upon two large randomized international clinical trials (German Dermatologic Cooperative Oncology Group (DeCOG-SLT) and Multicenter Selective Lymphadenectomy Trial II (MSLT-II)) published in 2016 and 2017, respectively, active surveillance has been demonstrated to have equivalent survival outcomes to completion lymphadenectomy (CLND) for a subset of patients who have microscopic lymph node disease. In this study, the changes in national practice patterns were examined regarding the utilization of CLND after positive sentinel lymph node biopsy (SLNB).

Methods

Using the National Cancer Database, CLND utilization was examined in SLN-positive patients diagnosed with melanoma between 2012 and 2016. A hierarchal logistical regression model with hospital-level random intercepts was constructed to examine the factors associated with SLNB followed by observation vs. SLNB with CLND.

Results

Of the 148,982 patients identified, 43% (n = 63,358) underwent SLNB and 10.3% (n = 6,551) had a SLNB with microscopic disease. CLND was performed for 57% (n = 2,817) of these patients. Patients were more likely to undergo CLND if they were ≤ 55 years of age (OR, 1.454; p ≤ 0.0001), ages 56 - 65 (OR, 1.127; p = 0.026), Charlson Deyo Score = 0 (OR, 2.088; p = 0.043), or were diagnosed with melanoma in 2012 (OR, 2.259, p ≤ 0.0001).

Conclusions

The utilization of CLND among patients with microscopic nodal melanoma was significantly lower in 2016 compared to 2012. Younger age, lack of comorbidities, and primary tumor location on the trunk or head/neck were associated with higher utilization of CLND.

Lymphadenectomy after a positive sentinel node biopsy in patients with cutaneous melanoma. A systematic review

Complete lymph node dissection (CLND) following a positive sentinel lymph node biopsy (SLNB) has been the standard treatment for years. However, there is increasing evidence that CLND could be omitted. Approximately 80% of patients with a positive sentinel node biopsy do not have additional nodal involvement; in these contexts, the SLNB could be diagnostic and therapeutic. However, in this group of patients, the therapeutic effect of CLND is unclear.

A systematic search was performed in EMBASE and MEDLINE (PubMed), for studies published between January 1, 2014 and December 31, 2019. Studies were included when they compared immediate CLND and observation after a positive sentinel node. The outcomes of interest were: Overall Survival (OS), melanoma-specific survival (MSS), and disease-free survival (DFS).

Eleven studies met the inclusion criteria. Two randomized clinical trials reported no differences in OS or MSS when complete lymph dissection was compared with observation alone. An increase in regional relapse was observed in the CLND group, and in one randomized controlled trial (RCT) the rate of disease-free survival was superior in those patients.

Most populations in both RCTs had low sentinel lymph node biopsy (SLNB) metastatic deposits, and head and neck melanomas were not included or underrepresented. When CNLD was omitted, an active surveillance protocol was carried out.

The evidence supports that CLND in SLNB positive patients does not confer a survival benefit. Sentinel tumor burden, localization of primary tumor, and feasibility of active surveillance should be taken into account in treatment decisions.

Predictors of Nonsentinel Lymph Node Metastasis in Cutaneous Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Although completion lymph node dissection (CLND) is not routinely performed for a positive sentinel lymph node (SLN) anymore, adjuvant therapy depends on the risk factors available from SLN biopsy, including the risk of nonsentinel node metastases (NSNM). A systematic review and meta-analysis was performed in an attempt to identify risk factors that could be used to predict the risk of NSNM.

MATERIALS AND METHODS

Medline, Web of Science, Embase, and Cochrane were searched for articles discussing predictive factors for NSNM. PRISMA guidelines were followed, and RevMan software was used to calculate pooled odds ratios (OR) using the Mantel-Haenszel test.

RESULTS

Fifty publications were suitable for additional analysis. The clinical and primary tumor factors that were consistently identified as risk factors for NSNMs were: age >50, T stage 3 or 4, Clark level IV/V, ulceration, microsatellitosis, lymphovascular invasion, nodular histology, and extremity versus trunk primary tumor location. SLN factors that predicted NSNMs were >1 positive SLN, SLN micrometastatic tumor burden, diameter >2 mm, extracapsular extension, nonsubcapsular location (Dewar), and Rotterdam > 1 mm or ≥ 0.1 mm.

CONCLUSIONS

The findings in this study support that many clinical and pathologic risk factors that can be assessed with SLN biopsy alone can be used to predict the risk of NSNMs. The factors identified in this review should be evaluated in clinical prediction models to predict the risk of NSNMS, a prediction that may be used to select patients for adjuvant therapy in high-risk melanoma.

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.

Nodal and systemic recurrence following observation of a positive sentinel lymph node in melanoma

BACKGROUND

Two RCTs found no survival benefit for completion lymphadenectomy after positive sentinel lymph node biopsy compared with observation with ultrasound in patients with melanoma. Recurrence patterns and regional control are not well described for patients undergoing observation alone.

METHODS

All patients with a positive sentinel node biopsy who did not have immediate completion lymphadenectomy were identified from a single-institution database (1995-2018). First recurrences were classified as node only, local and in-transit (LCIT) only, LCIT and nodal, or systemic. Regional control and factors associated with recurrence survival were analysed.

RESULTS

Median follow-up was 33 months. Of 370 patients, 158 (42·7 per cent) had a recurrence. The sites of first recurrence were node only (13·2 per cent), LCIT only (11·9 per cent), LCIT and nodal (3·5 per cent), and systemic (13·8 per cent). The 3-year postrecurrence melanoma-specific survival rate was 73 (95 per cent c.i. 54 to 86) per cent for patients with node-only first recurrence, and 51 (31 to 68) per cent for those with initial systemic recurrence. In multivariable analysis, ulceration in the primary lesion (hazard ratio (HR) 2·53, 95 per cent c.i. 1·27 to 5·04), disease-free interval 12 months or less (HR 2·38, 1·28 to 4·35), and systemic (HR 2·57, 1·16 to 5·65) or LCIT and nodal (HR 2·94, 1·11 to 7·79) first recurrence were associated significantly with decreased postrecurrence survival. Maintenance of regional control required therapeutic lymphadenectomy in 13·0 per cent of patients during follow-up.

CONCLUSION

Observation after a positive sentinel lymph node biopsy is associated with good regional control, permits assessment of the time to and pattern of recurrence, and spares lymphadenectomy-related morbidity in patients with melanoma.

Performance of models predicting residual lymph node disease in melanoma patients following sentinel lymph node biopsy

BACKGROUND

Among melanoma patients with a tumor-positive sentinel node biopsy (SNB), approximately 20% harbor disease in non-sentinel nodes (nSN), as determined by a completion lymph node dissection (CLND). CLND lacks a survival benefit and has high morbidity. This study assesses predictive factors for nSN metastasis and validates five models predicting nSN metastasis.

METHODS

Patients with invasive melanoma were identified from the BC Cancer Agency (2005-2015). Clinicopathological data were collected from 296 patients who underwent a CLND after a positive SNB. Multivariate analysis was completed to assess predictive variables in the study population. Five models were externally validated using overall model performance (Brier score [calibration and discrimination]) and discrimination (area under the ROC curve [AUC]).

RESULTS

Seventy-three patients had nSN metastasis at the time of CLND. The variable most predictive of nSN involvement was lymphovascular invasion (odds ratio [OR] 3.99; 95% confidence interval [CI] 1.67-9.54; p = 0.002). The highest discrimination was Lee et al. (2004) (AUC 0.68 [95% CI 0.61-0.75]), Rossi et al. (2018) (AUC 0.68 [95% CI 0.57-0.77]), and Bertolli et al. (2019) (AUC 0.68 [95% CI 0.60-0.75]). Rossi et al. (2018) had the lowest overall model performance (Brier score 0.44). Rossi et al. (2018) and Bertolli et al. (2019) had the ability to stratify patients to a risk of nSN involvement up to 99% and 95%, respectively.

CONCLUSION

Bertolli et al. (2019) had amongst the highest overall model performance, was the most clinically meaningful and is recommended as the preferred model for predicting nSN metastasis.

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.

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.

Factors associated with sentinel lymph node status and prognostic role of completion lymph node dissection for thick melanoma

INTRODUCTION

Sentinel lymph node (SLN) biopsy is useful for the prognostic stratification of patients with thick melanoma. Identifying which variables are associated with SLN involvement and establishing risk in different subgroups of patients could be useful for guiding the indication of SLN biopsy. The value of complete lymph node dissection (CLND) in patients with a positive SLN biopsy is currently under debate.

MATERIALS AND METHODS

To identify factors associated with SLN involvement in thick melanoma we performed a multicentric retrospective cohort study involving 660 patients with thick melanoma who had undergone SLN biopsy. To analyze the role of CLND in thick melanoma patients with a positive SLN biopsy, we built a multivariate Cox proportional hazards model for melanoma-specific survival (MSS) and disease-free survival (DFS) and compared 217 patients who had undergone CLND with 44 who had not.

RESULTS

The logistic regression analysis showed that age, histologic subtype, ulceration, microscopic satellitosis, and lymphovascular invasion were associated with nodal disease. The CHAID (Chi-squared Automatic Interaction Detection) decision tree showed ulceration to be the most important predictor of lymphatic involvement. For nonulcerated melanomas, the histologic subtype lentigo maligna melanoma was associated with a low rate of SLN involvement (4.3%). No significant differences were observed for DFS and MSS between the CLND performed and not-performed groups. Nodal status on CLND was associated with differences in DFS and MSS rates.

CONCLUSION

We identified subgroups of thick melanoma patients with a low likelihood of SLN involvement. CLND does not offer survival benefit, but provides prognostic information.

Defective levels of both circulating dendritic cells and T-regulatory cells correlate with risk of recurrence in cutaneous melanoma

BACKGROUND

Immune markers in the peripheral blood of melanoma patients provide useful information for clinical management although there is poor consensus on circulating cells which could putatively reflect the disease activity and play a prognostic role. Here, we investigated both dendritic cells (DCs) and T-regulatory cells (Tregs).

METHODS

The number of DC subsets as myeloid (m) and plasmacytoid was measured by flowcytometry in 113 melanoma patients in different clinical stages and correlated with the disease activity to evaluate the recurrence free survival (RFS) calculated as difference between baseline and post-surgical values in relation to the criteria for the melanoma staging, as primary tumor removal, sentinel lymph node biopsy and completion of lymph node dissection.

RESULTS

Circulating mDC levels were significantly lower in metastatic melanoma than in other stages and inversely correlated to Treg values while both populations were similarly expressed in inactive disease at stage I-III. Furthermore, the levels of these cells after melanoma removal were apparently related to the disease activity since their persistent defect reflected high risk of recurrence and reduced the RFS.

CONCLUSIONS

This work highlighted the role of immune cell measurement for the management of melanoma activity and the identification of patients at potential risk of recurrence based on the mDC ratio.

The Role of Completion Lymph Node Dissection for Sentinel Lymph Node-Positive Melanoma

PURPOSE AND METHODS

Completion lymph node dissection (CLND) for sentinel lymph node (SLN)-positive melanoma patients has been guideline-concordant standard of care since adoption of lymphatic mapping and SLN biopsy for the management of clinically node-negative melanoma patients more than 20 years ago. However, a trend for omission of CLND has been observed over the past decade, and we now have randomized, controlled clinical trial data to help guide treatment recommendations. Publication of these data prompted an American Society of Clinical Oncology-Society of Surgical Oncology 2018 clinical practice guideline update for these patients.

RESULTS AND CONCLUSIONS

Systematic review of current evidence supports a selective, individualized approach to CLND for SLN-positive melanoma. For low-risk, low-volume micrometastatic disease, SLN biopsy may be both diagnostic and therapeutic, and close clinical follow-up with imaging or CLND are reasonable options for appropriately selected patients. For higher-risk patients, omission of CLND requires careful consideration of risks versus benefits, relevant histopathology, and individualized patient discussion. This should address patient comorbidities and life expectancy, the predicted likelihood of additional positive nodes, availability of imaging surveillance, likelihood of adherence to imaging and clinical follow-up, consequences of regional recurrence, and the prognostic value of complete nodal staging and its impact on adjuvant therapy recommendations or clinical trial participation. Data on long-term outcomes, cost, and patient-reported quality of life measures are not yet available.

A model for predicting low probability of nonsentinel lymph node positivity in melanoma patients with a single positive sentinel lymph node

BACKGROUND

Identifying factors associated with nonsentinel lymph node (NSN) metastases in melanoma patients with a single positive sentinel lymph node (SLN) could aid decision making regarding adjuvant therapy. We describe a model for identifying patients with a single positive SLN at low risk for NSN metastasis.

METHODS

Factors associated with NSN metastasis in patients with a primary cutaneous melanoma and a single positive SLN who underwent completion lymph node dissection (CLND) were identified. These factors were used to construct a model for predicting the NSN status. The model was validated using a separate data set from another tertiary referral cancer center.

RESULTS

In the training data set, 111 patients had a single positive SLN. Of these, 27 had positive NSN. SLN tumor deposit diameter ≥0.75 mm (OR, 3.43; P = 0.047), age ≥40 (OR, 12.14; P = 0.024), and multifocal SLN tumor deposit location (OR, 4.16; P = 0.0096) were independently associated with NSN positivity. Patients with 0 to 1 of these risk factors had a low risk of NSN metastasis in both the training (7.5%) and validation (4.6%) data sets.

CONCLUSIONS

A combination of patient and SLN tumor burden characteristics can help to identify patients with a single positive SLN who are at a low risk of NSN metastasis.

Sentinel Lymph Node Biopsy and Completion Lymph Node Dissection for Melanoma

OPINION STATEMENT

This review critically evaluates recent trials which have challenged the practice of completion lymph node dissection (CLND) for melanoma patients diagnosed with regional metastasis by positive sentinel lymph node biopsy (SLNB). Two trials in the last 2 years, DeCOG-SLT and MSLT-II, found no significant differences in melanoma-specific survival between patients, whether they received immediate CLND or observation after positive SLNB, despite decreases in nodal recurrence achieved by dissection. These trials together disfavor routine CLND in most patients after positive SLNB. However, their conclusions are limited by study populations which overall harbored a lower burden of SLN disease. Special attention needs to be given to patients who do have higher risk disease, with SLN tumor burdens exceeding 1 mm in diameter, for whom CLND may remain both prognostic and therapeutic. Current guidelines thus recommend either CLND or careful observation after positive SLNB after appropriate risk stratification of patients. While a decline in CLND is inevitable, treatment of stage III melanoma is witnessing the concurrent rise of effective adjuvant therapies. PD-1 inhibitors such as nivolumab, or combination BRAF/MEK inhibitors for V600E or K mutant melanoma, which were previously available to only trial patients with completely resected stage III disease, are now approved for use in patients with positive SLNB alone. Providers are better equipped than ever to treat clinically occult, regional metastatic disease with SLNB followed by adjuvant therapy for most patients, but should take steps to avoid undertreatment of high-risk patients who may proceed to disease relapse or progression.

Patients with sentinel lymph node positive melanoma: Who needs completion lymph node dissection?

INTRODUCTION

Completion lymph node dissection (CLND) for melanoma after positive sentinel lymph node biopsy (SLNB) was recently shown to improve regional but not overall survival, likely due to the majority of patients harboring no further nodal disease. We sought to determine predictors of non-sentinel node (NSN) positivity.

METHODS

Retrospective review of prospectively collected data on melanoma patients undergoing SLNB.

RESULTS

116 patients underwent 119 CLNDs. The incidence of NSN positivity was 17.6%; the average number of positive NSNs in those cases was 1.5. Cervical and inguinofemoral location were most likely to yield positive NSN(s) (40% each). Conversely, the axilla was least likely at 18% (p < 0.001). The average number of nodes harvested was 13 for NSN negative cases and 20 for NSN positive cases (p = 0.005). Tumor thickness increased the probability of positive NSN(s) (OR 1.2, p = 0.02).

CONCLUSIONS

Tumor thickness and nodal basin were predictors of NSN metastasis, factors that could help determine which patients may benefit from CLND. Further, CLNDs with fewer nodes may inadequately clear residual nodal disease.

Favourable prognostic role of histological regression in stage III positive sentinel lymph node melanoma patients

BACKGROUND

Sentinel lymph node (SLN)-positive melanoma patients are a heterogeneous group of patients with survival rates ranging from ∼20 to over 80%. No data are reported concerning the role of histological regression on survival in stage III melanoma.

METHODS

The study included 365 patients with positive SLN from two distinct hospitals. The model was developed on patients from 'AOU Città della Salute e della Scienza di Torino', and externally validated on patients from IRCCS of Candiolo. Survival analyses were carried out according to the presence of regression and adjusted for all other prognostic factors.

RESULTS

Among patients followed at 'AOU Città della Salute e della Scienza di Torino' (n=264), the median follow-up time to death or censoring (whatever two events occurred earlier) was 2.7 years since diagnosis (interquartile range: 1.3-5.8). In all, 79 patients died from melanoma and 11 from other causes. Histological regression (n=43) was associated with a better prognosis (sub-HR=0.34, CI 0.12-0.92), whereas the other factors above showed an inverse association. In the external validation, the concordance index was 0.97 at 1 year and decreased to 0.66 at 3 years and to 0.59 at 5 years. Adding histological regression in the prognostic model increased the discriminative ability to 0.75 at 3 years and to 0.62 at 5 years. Finally, using a cutoff of 20% for the risk of death led to a net re-classification improvement of 15 and 11% at 3 and 5 years after diagnosis, respectively.

CONCLUSIONS

Histological regression could lead to an improvement in prognostic prediction in patients with stage III-positive SLN melanoma.

Prediction of Non-sentinel Node Status in Patients with Melanoma and Positive Sentinel Node Biopsy: An Italian Melanoma Intergroup (IMI) Study

BACKGROUND AND PURPOSE

Approximately 20% of melanoma patients harbor metastases in non-sentinel nodes (NSNs) after a positive sentinel node biopsy (SNB), and recent evidence questions the therapeutic benefit of completion lymph node dissection (CLND). We built a nomogram for prediction of NSN status in melanoma patients with positive SNB.

METHODS

Data on anthropometric and clinicopathological features of patients with cutaneous melanoma who underwent CLND after a positive SNB were collected from nine Italian centers. Multivariate logistic regression was utilized to identify predictors of NSN status in a training set, while model efficiency was validated in a validation set.

RESULTS

Data were available for 1220 patients treated from 2000 through 2016. In the training set (n = 810), the risk of NSN involvement was higher when (1) the primary melanoma is thicker or (2) sited in the trunk/head and neck; (3) fewer nodes are excised and (4) more nodes are involved; and (5) the lymph node metastasis is larger or (6) is deeply located. The model showed high discrimination (area under the receiver operating characteristic curve 0.74, 95% confidence interval [CI] 0.70-0.79) and calibration (Brier score 0.16, 95% CI 0.15-0.17) performance in the validation set (n = 410). The nomogram including these six clinicopathological variables performed significantly better than five other previously published models in terms of both discrimination and calibration.

CONCLUSIONS

Our nomogram could be useful for follow-up personalization in clinical practice, and for patient risk stratification while conducting clinical trials or analyzing their results.

Malignant Melanoma: Beyond the Basics

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Discuss the initial management of cutaneous malignant melanoma with regard to diagnostic biopsy and currently accepted resection margins. 2. Be familiar with the management options for melanoma in specific situations such as subungual melanoma, auricular melanoma, and melanoma in the pregnant patient. 3. Discuss the differentiating characteristics of desmoplastic melanoma and its treatment options. 4. List the indications for sentinel lymph node biopsy and be aware of the ongoing trials and current literature. 5. Discuss the medical therapies available to patients with metastatic melanoma.

SUMMARY

Management of the melanoma patient is a complex and evolving subject. Plastic surgeons should be aware of the recent changes in the field. Excisional biopsy remains the gold standard for diagnosis, although there is no evidence that use of other biopsy types alters survival or recurrence. Wide local excisions should be carried out with margins as recommended by National Comprehensive Cancer Network guidelines according to lesion Breslow depth, with sentinel lymph node biopsy being offered to all medically suitable candidates with intermediate thickness melanomas (1.0 to 4.0 mm), and with sentinel lymph node biopsy being considered for high-risk lesions (ulceration and/or high mitotic figures) with melanomas of 0.75 to 1.0 mm. Melanomas diagnosed during pregnancy can be treated with preoperative lymphoscintigraphy and wide local excision under local anesthesia, with sentinel lymph node biopsy under general anesthesia delayed until after delivery. Management of desmoplastic melanoma is currently controversial with regard to the indications for sentinel lymph node biopsy and the efficacy of postoperative radiation therapy. Subungual and auricular melanoma have evolved from being treated by amputation of the involved appendage to less radical procedures-ear reconstruction is now attempted in the absence of gross invasion into the perichondrium, and subungual melanomas may be treated with wide local excision down to and including the periosteum, with immediate full-thickness skin grafting over bone. Although surgical treatment remains the current gold standard, recent advances in immunotherapy and targeted molecular therapy for metastatic melanoma show great promise for the development of medical therapies for melanoma.

Regression in cutaneous melanoma: a comprehensive review from diagnosis to prognosis

Histological regression in primary cutaneous melanoma occurs in 10-35% of cases. Although a large body of literature exists to suggest that histological regression serves very little purpose in predicting biologic behaviour with melanoma, recognizing the presence of regression at clinical and histological ground may still retain some value in grading melanoma aggressiveness. In the current review, a comprehensive overview of the main aspects of regression will be provided. Histologically, many classifications have been reported so far, but all of them only agreed on the presence of an infiltrate of lymphocytes admixed with pigment-laden macrophages underlying an atrophic epidermis with flattened rete ridges. Upon dermoscopy, regression is also named Blue White Scar-like areas and could be variably admixed with granularity or peppering. Almost fully regressed lesions represent a main diagnostic issue in dermoscopy, and thus, confocal microscopy can be of help to identify whether the tumour is melanocytic or not. The clinical utility of regression as a prognostic factor has been challenged recently. Nowadays, evidences showed that it is less likely associated to SLN metastases.

What Is New in Melanoma Genetics and Treatment?

New therapies for advanced melanoma have led to major advances, which, for the first time, showed improved survival for patients with this very challenging neoplasm. These new treatments are based on gene-targeted therapies or stimulation of immune responses. However, these treatments are not without challenges in terms of resistance and toxicity. Physicians should be aware of these side effects as prompt treatment may save lives. Melanoma genetics is also unravelling new genetic risk factors involving telomere genes as well as new gene pathways at the somatic level which may soon become therapeutic targets. It is also shedding new light onto the pathology of this tumour with links to neural diseases and longevity.

Complete lymph node dissection versus no dissection in patients with sentinel lymph node biopsy positive melanoma (DeCOG-SLT): a multicentre, randomised, phase 3 trial

BACKGROUND

Complete lymph node dissection is recommended in patients with positive sentinel lymph node biopsy results. To date, the effect of complete lymph node dissection on prognosis is controversial. In the DeCOG-SLT trial, we assessed whether complete lymph node dissection resulted in increased survival compared with observation.

METHODS

In this multicentre, randomised, phase 3 trial, we enrolled patients with cutaneous melanoma of the torso, arms, or legs from 41 German skin cancer centres. Patients with positive sentinel lymph node biopsy results were eligible. Patients were randomly assigned (1:1) to undergo complete lymph node dissection or observation with permuted blocks of variable size and stratified by primary tumour thickness, ulceration of primary tumour, and intended adjuvant interferon therapy. Treatment assignment was not masked. The primary endpoint was distant metastasis-free survival and analysed by intention to treat. All patients in the intention-to-treat population of the complete lymph node dissection group were included in the safety analysis. This trial is registered with ClinicalTrials.gov, number NCT02434107. Follow-up is ongoing, but the trial no longer recruiting patients.

FINDINGS

Between Jan 1, 2006, and Dec 1, 2014, 5547 patients were screened with sentinel lymph node biopsy and 1269 (23%) patients were positive for micrometastasis. Of these, 483 (39%) agreed to randomisation into the clinical trial; due to difficulties enrolling and a low event rate the trial closed early on Dec 1, 2014. 241 patients were randomly assigned to the observation group and 242 to the complete lymph node dissection group. Ten patients did not meet the inclusion criteria, so 233 patients were analysed in the observation group and 240 patients were analysed in the complete lymph node dissection group, as the intention-to-treat population. 311 (66%) patients (158 in the observation group and 153 in the dissection group) had sentinel lymph node metastases of 1 mm or less. Median follow-up was 35 months (IQR 20-54). Distant metastasis-free survival at 3 years was 77·0% (90% CI 71·9-82·1; 55 events) in the observation group and 74·9% (69·5-80·3; 54 events) in the complete lymph node dissection group. In the complete lymph node dissection group, grade 3 and 4 events occurred in 15 patients (6%) and 19 patients (8%) patients, respectively. Adverse events included lymph oedema (grade 3 in seven patients, grade 4 in 13 patients), lymph fistula (grade 3 in one patient, grade 4 in two patients), seroma (grade 3 in three patients, no grade 4), infection (grade 3 in three patients, no grade 4), and delayed wound healing (grade 3 in one patient, grade 4 in four patients); no serious adverse events were reported.

INTERPRETATION

Although we did not achieve the required number of events, leading to the trial being underpowered, our results showed no difference in survival in patients treated with complete lymph node dissection compared with observation only. Consequently, complete lymph node dissection should not be recommended in patients with melanoma with lymph node micrometastases of at least a diameter of 1 mm or smaller.

FUNDING

German Cancer Aid.

Prognostic Role of Multiple Lymphatic Basin Drainage in Sentinel Lymph Node-Negative Trunk Melanoma Patients: A Multicenter Study from the Italian Melanoma Intergroup

BACKGROUND

Multiple lymphatic basin drainage (MLBD) is frequently observed in patients with trunk melanoma undergoing sentinel lymph node (SLN) biopsy. Conflicting data regarding the prognostic association of MLBD in SLN-negative patients have been reported. This study aimed to investigate the prognostic role of MLBD in patients with negative SLN biopsy.

METHODS

Retrospective data from 656 melanoma patients who underwent a SLN biopsy (1991-2012) at six Italian centers were gathered in a multicenter database. MLBD was defined as lymphoscintigraphic and intraoperative identification of an SLN in more than one nodal basin. Clinical and pathologic variables were recorded and analyzed for their impact on survival.

RESULTS

SLN-negative patients with MLBD were at lower risk of melanoma recurrence [hazard ratio (HR) 0.73, P = 0.05) and melanoma-related death (HR 0.68, P = 0.001) independent of common staging features. Multivariable Cox analyses of disease-free interval (DFI) and disease-specific survival (DSS) showed that MLBD maintained a favorable role and ulceration an unfavorable role. Histologic regression was independently associated only with DFI. When survival was stratified according to presence of MLBD, histologic regression and Breslow thickness <2 mm were associated with improved DFI (5-year DFI: 96.9 vs. 66,1 %, respectively; HR 0.48, P < 0.001) and DSS (5-year DSS: 96.7 vs. 71.8 %, respectively; HR 0.52, P = 0.005) compared to patients without these three favorable parameters.

CONCLUSIONS

Patients with negative SLN biopsy results have better prognosis when two or more lymphatic basins are identified and analyzed. Further research is required to investigate the mechanisms behind this evidence.

Current staging and prognostic factors in melanoma

The current American Joint Commission for Cancer staging system for melanoma includes thickness, ulceration, and mitotic index as primary tumor factors for patients with stage I and II disease. Number and size of nodal metastases, presence of satellitosis and in-transit disease, and tumor ulceration status categorize patients with stage III disease. Presence and location of distant metastatic disease and increased lactate dehydrogenase level stratify prognosis in patients with stage IV disease. Factors predictive of sentinel lymph node positivity are also studied, particularly in patients with T1 melanomas, but are not always congruent with those predictive of survival.

The long-term results and prognostic significance of cutaneous melanoma surgery using sentinel node biopsy with triple technique

BACKGROUND

The sentinel lymph node biopsy (SLN) is a basic staging method in all primary cutaneous melanomas ≥pT1b. The standard technique is a triple technique consisting of preoperative lymphoscintigraphy, intraoperative blue-dye lymphography, and gamma-probe assessment. We performed the analysis of long-term results in a very large one-institution series of cutaneous melanoma patients.

METHODS

We have analyzed treatment results of a group of 1764 consecutive patients with cutaneous melanoma, who underwent SLN biopsy between 1997 and 2008 in one tertiary center. Additionally, we have analyzed the outcomes of a group of 473 patients with positive SLN biopsy undergoing completion lymph node dissection (CLND). Median follow-up time was 5.3 years.

RESULTS

Metastases to SLN (SLN+) were found in 19.9%. Eight-year overall survival (OS) rate in the entire group was 73.5%, 80% without SLN metastases (SLN-) and 50% in group with SLN+ (p < 0.001). Independent prognostic factors for OS were as follows: presence of metastases to SLN, primary tumor ulceration, and higher mitotic index (>5/mm(2)) of primary tumor. The nodal recurrences in the biopsied lymphatic basin were 5.4%. The metastases to non-sentinel lymph nodes (NSLN found in 27% of patients with SLN+) correlated (on multivariable logistic regression analysis) with primary tumor thickness >4 mm, SLN metastatic deposit size >1 mm, and extracapsular involvement of SLN. In an additionally analyzed SLN+ group, the NSLN involvement was related to poorer prognosis (8-year OS rate NSLN- vs NSLN+: 59.6 vs. 34.7%, respectively). The independent prognostic factors for OS in the SLN+ group were a higher Breslow thickness and ulceration of primary tumor, metastases to more than 1 lymph nodes.

CONCLUSIONS

The long-term results confirm crucial prognostic significance of SLN biopsy in cutaneous melanoma. We identified factors related to NSLN involvement, which in the future may limit indications for CLND.

EANM practice guidelines for lymphoscintigraphy and sentinel lymph node biopsy in melanoma

PURPOSE

Sentinel lymph node biopsy is an essential staging tool in patients with clinically localized melanoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with melanoma.

METHODS

These practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, national nuclear medicine societies, the European Society of Surgical Oncology (ESSO) and the European Association for Research and Treatment of Cancer (EORTC) melanoma group. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).

CONCLUSION

The present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of melanoma patients.

The lymph node microenvironment and its role in the progression of metastatic cancer

Lymph nodes are initial sites for cancer metastasis in many solid tumors. However, their role in cancer progression is still not completely understood. Emerging evidence suggests that the lymph node microenvironment provides hospitable soil for the seeding and proliferation of cancer cells. Resident immune and stromal cells in the lymph node express and secrete molecules that may facilitate the survival of cancer cells in this organ. More comprehensive studies are warranted to fully understand the importance of the lymph node in tumor progression. Here, we will review the current knowledge of the role of the lymph node microenvironment in metastatic progression.

Ultrasound-guided fine needle aspiration cytology as an addendum to sentinel lymph node biopsy can perfect the staging strategy in melanoma patients

BACKGROUND

Ultrasound guided fine needle aspiration cytology (US-guided FNAC) can identify microscopic involvement of lymph nodes as in breast cancer and avoid surgical sentinel node (SN). Its utility in melanoma patients is controversial and subject of this study.

METHODS

Between 2001 and 2010 over 1000 stage I/II consecutive melanoma patients prospectively underwent US-FNAC prior to SN biopsy. All patients underwent lymphoscintigraphy prior to US-FNAC. The Berlin US morphology criteria: Peripheral perfusion (PP), loss of central echoes (LCE) and balloon shaped (BS) were registered. FNAC was performed in case of presence of any of these factors. SN tumour burden was measured according to the Rotterdam criteria. All patients underwent SN or lymph node dissection (LND) in case of positive FNAC.

FINDINGS

Mean/median Breslow thickness was 2.58/1.57 mm. Mean/median follow-up was 56/53 months (1-132). SN positivity rate was 21%. US-FNAC Sensitivity was 71% (US only) and 51% (US-FNAC). Sensitivity of US-FNAC was highest for T4 (76%) and ulcerated melanomas (63%). PP, LCE and BS had sensitivity of 69%, 24% and 24% respectively. Sensitivity of US-FNAC increased with increasing SN tumour burden. PP was an early sign of metastasis (58% in <0.1mm metastases). Threshold size of a metastasis for FNAC was 0.3mm. Five-year survival correlated to US-FNAC status (95% in negative and 59% in positive).

INTERPRETATION

Ultrasound guided FNAC (US-FNAC) according to the Berlin morphology criteria could correctly identify at least half of all tumour positive sentinel nodes, prior to the surgical SN procedure. Peripheral perfusion is an early sign of metastasis, which is very sensitive, but with lower positive predictive value (PPV). It is responsible for the sensitivity of the procedure. Balloon shape is a sign of advanced metastases, with lower sensitivity, but high PPV. US-FNAC sensitivity correlated with increasing T-stage, ulceration of the primary and increasing SN tumour burden. US-FNAC status accurately predicts survival.

Contemporary controversies and perspectives in the staging and treatment of patients with lymph node metastasis from melanoma, especially with regards positive sentinel lymph node biopsy

The management of melanoma lymph node metastasis particularly when detected by sentinel lymph node biopsy (SLNB) is still controversial. Results of the only randomized trial conducted to assess the therapeutic value of SLNB, the Multicenter Selective Lymphadenectomy Trial (MSLT-1), have not conclusively proven the effectiveness of this procedure but are interpreted by the authors and guidelines as indicating SLNB is standard of care. After surgery, interferon alpha had a small survival benefit and radiotherapy has limited effectiveness for patient at high-risk of regional recurrence. New drugs, including immune modulating agents and targeted therapies, already shown to be effective in patients with distant metastasis, are being evaluated in the adjuvant setting. In this regard, ensuring high quality of surgery through the identification of reliable quality assurance indicators and improving the homogeneity of prognostic stratification of patients entered onto clinical trials is paramount. Here, we review the controversial issues regarding the staging and treatment of melanoma patients with lymph node metastasis, present a summary of important and potentially practice changing ongoing research and provide a commentary on what it all means at this point in time.