Complete Lymph Node Dissection in Melanoma: A Systematic Review and Meta-Analysis

National Practice Patterns in the Management of the Regional Lymph Node Basin After Positive Sentinel Lymph Node Biopsy for Cutaneous Melanoma

BACKGROUND

Immediate completion lymph node dissection (CLND) for patients with sentinel lymph node (SLN) metastasis from cutaneous melanoma has been replaced largely by ultrasound nodal surveillance since the publication of two landmark trials in 2016 and 2017. National practice patterns of CLND remain poorly characterized.

METHODS

Patients with a diagnosis of cutaneous melanoma in 2016 and 2018 without clinical nodal disease who underwent sentinel lymph node biopsy (SLNB) were identified from the National Cancer Database (NCDB). Characteristics associated with CLND were analyzed by uni- and multivariate logistic regression. Overall survival (OS) was estimated using Kaplan-Meier and Cox proportional hazards regression analyses.

RESULTS

Of the 3517 patients included in the study, 1405 had disease diagnosed in 2016. The patients with cutaneous melanoma diagnosed in 2016 had a median age of 60 years and a tumor thickness of 2.3 mm compared to 62 years and 2.4 mm, respectively, for the patients with cutaneous melanoma diagnosed in 2018. According to the NCDB, 40 % (n = 559) of the patients underwent CLND in 2016 compared with 6 % (n = 132) in 2018. The factors associated with receipt of CLND in 2018 included younger age (odds ratio [OR], 0.97; 95 % confidence interval [CI], 0.95-0.99; p = 0.001), rural residence (OR, 3.96; 95 % CI, 1.50-10.49; p = 0.006), head/neck tumor location (OR, 1.88; 95 % CI, 1.10-3.23; p = 0.021), and more than one positive SLN (OR, 1.80; 95 % CI, 1.17-2.76; p = 0.007). The 5-year OS did not differ between the patients who received SLNB only and those who underwent CLND (hazard ratio [HR], 0.93; p = 0.54).

CONCLUSION

The rates of CLND have decreased nationally. However, patients with head/neck primary tumors who live in rural locations are more likely to undergo CLND, highlighting populations for which treatment may be non-uniform with national practice patterns.

Rethinking the biology of metastatic melanoma: a holistic approach

Over the past decades, melanoma-related mortality has remained nearly stable. The main reason is treatment failure of metastatic disease and the inherently linked knowledge gap regarding metastasis formation. In order to elicit invasion, melanoma cells manipulate the tumor microenvironment, gain motility, and adhere to the extracellular matrix and cancer-associated fibroblasts. Melanoma cells thereby express different cell adhesion molecules like laminins, integrins, N-cadherin, and others. Epithelial-mesenchymal transition (EMT) is physiological during embryologic development, but reactivated during malignancy. Despite not being truly epithelial, neural crest-derived malignancies like melanoma share similar biological programs that enable tumorigenesis, invasion, and metastasis. This complex phenomenon is termed phenotype switching and is intertwined with oncometabolism as well as dormancy escape. Additionally, it has been shown that primary melanoma shed exosomes that create a favorable premetastatic niche in the microenvironment of secondary organs and lymph nodes. Although the growing body of literature describes the aforementioned concepts separately, an integrative holistic approach is missing. Using melanoma as a tumor model, this review will shed light on these complex biological principles in an attempt to clarify the mechanistic metastatic pathways that dictate tumor and patient fate.

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.

The prognostic significance of non-sentinel lymph node metastasis in cutaneous and acral melanoma patients-A multicenter retrospective study

Background

Whether non‐sentinel lymph node (SLN)‐positive melanoma patients can benefit from completion lymph node dissection (CLND) is still unclear. The current study was performed to identify the prognostic role of non‐SLN status in SLN‐positive melanoma and to investigate the predictive factors of non‐SLN metastasis in acral and cutaneous melanoma patients.

Methods

The records of 328 SLN‐positive melanoma patients who underwent radical surgery at four cancer centers from September 2009 to August 2017 were reviewed. Clinicopathological data including age, gender, Clark level, Breslow index, ulceration, the number of positive SLNs, non‐SLN status, and adjuvant therapy were included for survival analyses. Patients were followed up until death or June 30, 2019. Multivariable logistic regression modeling was performed to identify factors associated with non‐SLN positivity. Log‐rank analysis and Cox regression analysis were used to identify the prognostic factors for disease‐free survival (DFS) and overall survival (OS).

Results

Among all enrolled patients, 220 (67.1%) had acral melanoma and 108 (32.9%) had cutaneous melanoma. The 5‐year DFS and OS rate of the entire cohort was 31.5% and 54.1%, respectively. More than 1 positive SLNs were found in 123 (37.5%) patients. Positive non‐SLNs were found in 99 (30.2%) patients. Patients with positive non‐SLNs had significantly worse DFS and OS (log‐rank P < 0.001). Non‐SLN status (P = 0.003), number of positive SLNs (P = 0.016), and adjuvant therapy (P = 0.025) were independent prognostic factors for DFS, while non‐SLN status (P = 0.002), the Breslow index (P = 0.027), Clark level (P = 0.006), ulceration (P = 0.004), number of positive SLNs (P = 0.001), and adjuvant therapy (P = 0.007) were independent prognostic factors for OS. The Breslow index (P = 0.020), Clark level (P = 0.012), and number of positive SLNs (P = 0.031) were independently related to positive non‐SLNs and could be used to develop more personalized surgical strategy.

Conclusions

Non‐SLN‐positive melanoma patients had worse DFS and OS even after immediate CLND than those with non‐SLN‐negative melanoma. The Breslow index, Clark level, and number of positive SLNs were independent predictive factors for non‐SLN status.

New Trends in Cutaneous Melanoma Surgery

The main surgical treatment for melanoma consists in wide surgical excision of the primary lesion and the sentinel node but in recent times management of melanoma is rapidly evolving with the introduction of new systemic therapies, like BRAF inhibitors, MEK inhibitors and antibodies anti-PD-1 that show good results in controlling even advanced stages of the disease. This review aims to present data for the optimal surgical management of patients with malignant melanoma.

Sentinel Lymph Node Biopsy and Complete Lymph Node Dissection for Melanoma

Purpose of Review

The main surgical treatment for invasive malignant melanoma consists of wide surgical and examination of the sentinel node and in selected cases complete lymph node dissection. The aim of this review is to present data for the optimal surgical management of patients with malignant melanoma.

Recent Findings

A surgical excision margin of 1–2 cm is recommended for invasive melanoma depending on the thickness of the melanoma. Sentinel node biopsy may be considered for patients with at least T1b melanomas thickness 0.8 to 1.0 mm or less than 0.8 mm Breslow thickness with ulceration, classified as T1b lesion, per recent AJCC guidelines. Two randomized controlled trials have been published—DeCOG (German Dermatologic Cooperative Oncology Group Selective Lymphadenectomy) and MSLT-2 (Multicenter Selective Lymphadenectomy Trial) comparing the complete lymph node dissection (CLND) with observation after positive sentinel node biopsy. In the MSLT-2 study, the disease control rate was improved in the immediate CLND group compared with observation but there was no difference in 3-year melanoma specific survival (86% ± 1.3% and 86% ± 1.2%, respectively; p = 0.42). Isolated limb perfusion (ILP) or isolated limb infusion (ILI) with melphalan and actinomycin D is recommended for large and multiple in-transit metastases and satellite metastases in the extremities when local excision is considered ineffective or too extensive.

Summary

In light of new adjuvant treatment options and new indications for checkpoint inhibitors, and the lack of survival benefit after CLND, we can expect open surgery to decrease in melanoma disease.

Melanoma & nuclear medicine: new insights & advances

The contribution of nuclear medicine to management of melanoma patients is increasing. In intermediate-thickness N0 melanomas, lymphoscintigraphy provides a roadmap for sentinel node biopsy. With the introduction of single-photon emission computed tomography images with integrated computed tomography (SPECT/CT), 3D anatomic environments for accurate surgical planning are now possible. Sentinel node identification in intricate anatomical areas (pelvic cavity, head/neck) has been improved using hybrid radioactive/fluorescent tracers, preoperative lymphoscintigraphy and SPECT/CT together with modern intraoperative portable imaging technologies for surgical navigation (free-hand SPECT, portable gamma cameras). Furthermore, PET/CT today provides 3D roadmaps to resect 18F-fluorodeoxyglucose-avid melanoma lesions. Simultaneously, in advanced-stage melanoma and recurrences, 18F-fluorodeoxyglucose-PET/CT is useful in clinical staging and treatment decision as well as in the evaluation of therapy response. In this article, we review new insights and recent nuclear medicine advances in the management of melanoma patients.

Nevus Blue as a Sporadic Finding in a Patient with a Blue Toe?

BACKGROUND:

Blue nevus is an interesting finding, which aetiology and risk of locoregional and distant metastasis have not yet been fully clarified. It may be inherited or acquired, with sporadic cases usually presented as solitary lesions. It is often localised in the area of the head and less often on the arms, legs or trunk. Blue nevi are formations with relatively low but still possible potential for switching to melanoma.

CASE REPORT:

The patient we described was hospitalised for pronounced cyanosis of the small toe of the right foot, accompanied by painful symptoms at rest and pain symptoms for a few weeks. Using inpatient paraclinical and instrumental tests, the patient was diagnosed with cholesterol microembolism. During the dermatological examination, blue nevus on the contralaterally localised limb was also diagnosed as a sporadic finding. According to the patient’s medical history, the finding had existed for many years, but in the last few months, the patient has observed growth and progression in the peripheral zone of the nevus without any additional clinical symptoms.

CONCLUSION:

Due to the risk of progression to melanoma, the lesion was removed by radical excision, and the defect was closed by tissue advancement flap.

The value of metastasectomy in stage IV cutaneous melanoma

Cutaneous melanoma is an aggressive neoplasia of melanocytes. Prognosis is dependent on tumor stage. Stage IV melanoma is characterized by the occurrence of distant metastases. Response of metastases to classical chemotherapy is limited and toxicity of treatment is high. In recent years, new developments in immunotherapy and targeted therapies improved prognosis of stage IV melanoma patients with better tolerability of treatment. There is no dispute about surgical treatment of primary melanoma. But what is the value of metastasectomy in the era of new systemic treatments? This review aims to discuss available data for surgical removal of distant metastases for several organs and tissues. The available evidence suggests that for selected patients with possible complete resection of all tumor metastases, metastasectomy remains an effective treatment option with a benefit in overall survival.