Accuracy of the non-sentinel node risk score (N-SNORE) in patients with cutaneous melanoma and positive sentinel lymph nodes: a retrospective study

Risk Stratification of Sentinel Node Metastasis Disease Burden and Phenotype in Stage III Melanoma Patients

BACKGROUND

Currently, all patients with American Joint Committee on Cancer (AJCC) pT2b-pT4b melanomas and a positive sentinel node biopsy are now considered for adjuvant systemic therapy without consideration of the burden of disease in the metastatic nodes.

METHODS

This was a retrospective cohort analysis of 1377 pT1-pT4b melanoma patients treated at an academic cancer center. Standard variables regarding patient, primary tumor, and sentinel node characteristics, in addition to sentinel node metastasis maximum tumor deposit size (MTDS) in millimeters and extracapsular spread (ECS) status, were analyzed for predicting disease-specific survival (DSS).

RESULTS

The incidence of SN+ was 17.3% (238/1377) and ECS was 10.5% (25/238). Increasing AJCC N stage was associated with worse DSS. There was no difference in DSS between the IIIB and IIIC groups. Subgroup analyses showed that the optimal MTDS cut-point was 0.7 mm for the pT1b-pT4a SN+ subgroups, but there was no cut-point for the pT4b SN+ subgroup. Patients with MTDS <0.7 mm and no ECS had similar survival outcomes as the N0 patients with the same T stage. Nodal risk categories were developed using the 0.7 mm MTDS cut-point and ECS status. The incidence of low-risk disease, according to the new nodal risk model, was 22.3% (53/238) in the stage III cohort, with 49% (26/53) in the pT2b-pT3a and pT3b-pT4a subgroups and none in the pT4b subgroup. Similar outcomes were observed for overall and distant metastasis-free survival.

CONCLUSION

We propose a more granular classification system, based on tumor burden and ECS status in the sentinel node, that identifies low-risk patients in the AJCC IIIB and IIIC subgroups who may otherwise be observed.

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.

Final Analysis of DeCOG-SLT Trial: No Survival Benefit for Complete Lymph Node Dissection in Patients With Melanoma With Positive Sentinel Node

PURPOSE

We have previously reported on the 3-year results of the phase III German Dermatologic Cooperative Oncology Group trial (DeCOG; ClinicalTrials.gov identifier: NCT02434107) comparing distant metastasis-free survival (DMFS), recurrence-free survival (RFS), and overall survival (OS) in patients with positive sentinel lymph-node biopsy who were randomly assigned to complete lymph node dissection (CLND) or observation. Here, we report the final analysis with 72 months of median follow up.

PATIENTS AND METHODS

The multicenter randomized phase III trial included patients with cutaneous melanoma of the trunk and extremities who were randomly assigned (1:1) to undergo CLND or observation. DMFS was analyzed as the primary end point, and RFS, OS, and recurrences in the regional lymph node basin were secondary end points. The analysis was by intention to treat. Disease and survival information were collected quarterly.

RESULTS

From January 2006 to December 2014, 5,547 patients were screened to identify 1,256 with metastases in the sentinel lymph node (SLN). Of these, 483 (39%) were included: 241 in the observation arm and 242 in the CLND arm. In the final analysis, median follow up was 72 months (interquartile range, 67-77 months). No significant treatment-related difference was seen in the 5-year DMFS between the observation and CLND arms (67.6% v 64.9%, respectively; hazard ratio [HR], 1.08; P = .87). The 5-year RFS and OS also showed no difference (HR, 1.01 and 0.99, respectively). Grade 3 and 4 adverse effects occurred in 32 patients (13%) in the CLND arm; lymphedema (n = 20) and delayed wound healing (n = 5) were most common and no serious adverse events were reported.

CONCLUSION

The final results of the German Dermatologic Cooperative Oncology Group trial with a median follow up of 72 months showed higher event rates, but similar HRs compared with those at the 3-year analysis. These results confirm that immediate CLND in SLN-positive patients is not superior to observation in terms of DMFS, RFS, or OS and support not recommending CLND in patients with SLN metastasis.

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.

Unique Genes in Tumor-Positive Sentinel Lymph Nodes Associated with Nonsentinel Lymph Node Metastases in Melanoma

BACKGROUND

Current risk assessment tools to estimate the risk of nonsentinel lymph node metastases after completion lymphadenectomy for a positive sentinel lymph node (SLN) biopsy in cutaneous melanoma are based on clinical and pathologic factors. We identified a novel genetic signature that can predict non-SLN metastases in patients with cutaneous melanoma staged with a SLN biopsy.

METHODS

RNA was collected for tumor-positive SLNs in patients staged by SLN biopsy for cutaneous melanoma. All patients with a tumor-positive SLN biopsy underwent completion lymphadenectomy. A 1:10 case:control series of positive and negative non-SLN patients was analyzed by microarray and quantitative RT-PCR. Candidate differentially expressed genes were validated in a 1:3 case:control separate cohort of positive and negative non-SLN patients.

RESULTS

The 1:10 case:control discovery set consisted of 7 positive non-SLN cases matched to 70 negative non-SLN controls. The cases and controls were similar with regards to important clinicopathologic factors, such as gender, primary tumor site, age, ulceration, and thickness. Microarray and RT-PCR identified six potential differentially expressed genes for validation. In the 40-patient separate validation set, 10 positive non-SLN patients were matched to 30 negative non-SLN controls based on gender, ulceration, age, and thickness. Five of the six genes were differentially expressed. The five gene panel identified patients at low (7.1%) and high risk (66.7%) for non-SLN metastases.

CONCLUSIONS

A novel, non-SLN gene score based on differential expressed genes in a tumor-positive SLN can identify patients at high and low risk for non-SLN metastases.

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.

Impact of Completion Lymph Node Dissection on Patients with Positive Sentinel Lymph Node Biopsy in Melanoma

BACKGROUND

Whether patients with positive SLNB should undergo complete lymph node dissection (CLND) is an important unanswered clinical question.

STUDY DESIGN

Patients diagnosed with positive SLNB at a melanoma referral center from 1991 to 2013 were studied. Outcomes of patients who underwent CLND were compared with those who did not undergo immediate CLND (observation [OBS] group).

RESULTS

There were 471 patients who had positive SLNB; 375 (79.6%) in the CLND group and 96 (20.4%) in the OBS group. The groups were similar except that the CLND group was younger and had more sentinel nodes removed. Five-year nodal recurrence-free survival was significantly better in the CLND group compared with the OBS group (93.1% vs 84.4%; p = 0.005). However, 5-year (66.4% vs 55.2%) and 10-year (59.5% vs 45.0%) distant metastasis-free survival rates were not significantly different (p = 0.061). The CLND group's melanoma-specific survival (MSS) rate was superior to that of the OBS group; 5-year MSS rates were 73.7% vs 65.5% and 10-year MSS rates were 66.8% vs 48.3% (p = 0.015). On multivariate analysis, CLND was associated with improved MSS (hazard ratio = 0.60; 95% CI, 0.40-0.89; p = 0.011) and lower nodal recurrence (hazard ratio = 0.46; 95% CI, 0.24-0.86; p = 0.016). Increased Breslow thickness, older age, ulceration, and trunk melanoma were all associated with worse outcomes. On subgroup analysis, the following factors were associated with better outcomes from CLND: male sex, nonulcerated primary, intermediate thickness, Clark level IV or lower extremity tumors.

CONCLUSIONS

Treatment of positive SLNB with CLND was associated with improved MSS and nodal recurrence rates. Follow-up beyond 5 years was needed to see a significant difference in MSS rates.

The potential complementary role of targeted alpha therapy in the management of metastatic melanoma

Standard treatments for metastatic melanoma have recently extended survival although many patients still succumb. Targeted alpha therapy (TAT) is a new therapeutic approach in which a cancer-targeting vector is labeled with an alpha-emitting radioisotope. Alpha-particles have the shortest range and highest energy transfer, and produce localized, high-density and lethal ionization damage to DNA. Thus, the targeted radiation can kill isolated cancer cells circulating in blood and lymphatic vessels, regress metastatic cancer cell clusters, and disrupt the vasculature of solid tumors. Preclinical and clinical studies of TAT for metastatic melanoma demonstrate its safety and anti-tumor activity. We recommend ways in which TAT can be used to treat small-volume disease sometimes in conjunction with cytoreductive anti-melanoma therapies.