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

Modern Approach to Melanoma Adjuvant Treatment with Anti-PD1 Immune Check Point Inhibitors or BRAF/MEK Targeted Therapy: Multicenter Real-World Report

BACKGROUND

The landscape of melanoma management changed as randomized trials have launched adjuvant treatment.

MATERIALS AND METHODS

An analysis of data on 248 consecutive melanoma stage III and IV patients given adjuvant therapy in eight centers (February 2019 to January 2021) was conducted.

RESULTS

The analyzed cohort comprised 147 melanoma patients given anti-PD1 (33% nivolumab, 26% pembrolizumab), and 101 (41%) were given dabrafenib plus trametinib (DT). The 2-year overall survival (OS), relapse-free survival (RFS), and distant-metastases-free survival (DMFS) rates were 86.7%, 61.4%, and 70.2%, respectively. The disease stage affected only the RFS rate; for stage IV, it was 52.2% (95% CI: 33.4-81.5%) vs. 62.5% (95% CI: 52.3-74.8%) for IIIA-D, p = 0.0033. The type of lymph node surgery before adjuvant therapy did not influence the outcomes. Completion of lymph node dissection cessation after positive SLNB did not affect the results in terms of RFS or OS. Treatment-related adverse events (TRAE) were associated with longer 24-month RFS, with a rate of 68.7% (55.5-84.9%) for TRAE vs. 56.6% (45.8-70%) without TRAE, p = 0.0031. For TRAE of grade ≥ 3, a significant decline in OS to 60.6% (26.9-100%; p = 0.004) was observed.

CONCLUSIONS

Melanoma adjuvant therapy with anti-PD1 or DT outside clinical trials appears to be effective and comparable with the results of registration studies. Our data support a de-escalating surgery approach in melanoma treatment.

New Zealand patients have a higher melanoma burden in sentinel nodes and completion lymphadenectomy than patients in MSLT-II

New Zealand has the highest rate of melanoma-related mortality in the world. Access to immunotherapy and radiology is limited and surgical treatment of regional disease remains important. A recent pilot study of a single health district observed a higher nodal melanoma burden than was reported in the second Multicentre Selective Lymphadenectomy Trial (MSLT-II). In this study, a series of regional censuses were undertaken covering the 10 years immediately prior to the publication of MSLT-II. The study population was seven District Health Boards covering 62.2% of the population of New Zealand across a 10-year period preceding MSLT-II. The primary outcomes measured were the size of sentinel lymph node metastases and non-sentinel node (NSN) positivity on completion lymph node dissection (CLND) for patients with a positive sentinel lymph node biopsy (SLNB). In the 2323 SLNB identified, the mean sentinel lymph node metastatic deposit size was larger compared to MSLT-II (2.55 vs. 1.07/1.11 mm). A greater proportion of New Zealand patients (44.2%) had metastatic deposits larger than 1 mm compared to MSLT-II (33.2/34.5%) and the rate of non-sentinel node involvement on CLND was also higher (22.2% vs. 11.5%). These findings indicate that New Zealand is a high-risk population for nodal melanoma metastases. Due to these differences, the conclusions of MSLT-II may not be able to be applied to melanoma patients in the 7 regions studied in New Zealand.

Real-World Adherence to Nodal Surveillance for Sentinel Lymph Node-Positive Melanoma

BACKGROUND

Patients with sentinel lymph node-positive (SLN+) melanoma are increasingly undergoing active nodal surveillance over completion lymph node dissection (CLND) since the Second Multicenter Selective Lymphadenectomy Trial (MSLT-II). Adherence to nodal surveillance in real-world practice remains unknown.

METHODS

In a retrospective cohort of SLN+ melanoma patients who underwent nodal surveillance at a single institution from July 2017 through April 2021, this study evaluated adherence to nodal surveillance ultrasound (US). Adherence to nodal US was compared with adherence to other surveillance methods based on receipt of adjuvant therapy. Early recurrence data were reported using descriptive statistics.

RESULTS

Among 109 SLN+ patients, 37 (34%) received US surveillance at recommended intervals. Of the 72 (66%) non-adherent patients, 16 were lost to follow-up, and 33 had planned follow-up at an outside institution without available records. More patients had a minimum of bi-annual clinic visits (83%) and cross-sectional imaging (53%) compared to those who were adherent with nodal US. The patients who received adjuvant therapy (60%) had fewer ultrasounds (p < 0.01) but more exams (p < 0.01) and a trend toward more cross-sectional imaging (p = 0.06). Of the overall cohort, 26 patients (24%) experienced recurrence at a median follow-up period of 15 months. Of these recurrences, 10 were limited to the SLN basin, and all of these isolated nodal recurrences were resectable.

CONCLUSIONS

Pragmatic challenges to real-world delivery of nodal surveillance remain after MSLT-II, and adjuvant therapy appears to be associated with a decreased likelihood of US adherence. Understanding US utility alongside cross-sectional imaging will be critical as increasingly more patients undergo nodal surveillance and adjuvant therapy.

Waiving Subsequent Complete Lymph Node Dissection in Melanoma Patients with Positive Sentinel Lymph Node Does Not Result in Worse Outcome on 20-Year Analysis

Simple Summary

The aim of the present study was to investigate long-term outcomes of melanoma patients who had micrometastasis on sentinel lymph node (SLN) biopsy. We focused on the comparison between melanoma patients with and without complete lymph node dissection (CLND) following a positive SLN biopsy result. Patients without CLND did not significantly differ from patients with CLND in regard to age, gender, tumor thickness, tumor ulceration, capsule infiltration of SLN, and invasion level of SLN. On 10-year analysis, we did not observe a significantly increased risk for melanoma relapse or melanoma-specific death in patients who did not undergo CLND after the detection of micrometastases on SLN biopsy. On 20-year analysis, again, the patients without CLND had no significantly increased risk of melanoma relapse and worse melanoma-specific survival. Hence, our 10-year survival data confirm the current notion that waiving CLND in SLN-positive patients does not result in clinical disadvantages with respect to melanoma-specific survival. For the first time, we demonstrate on 20-year survival analysis that relapse rates and melanoma-specific survival does not significantly differ between patients with or without CLND on long-term follow-up.

Abstract

Complete lymph node dissection (CLND) following positive sentinel lymph node (SLN) biopsy has been the standard of care for decades. We aimed to study melanoma patients with an emphasis on the outcome of patients with versus without CLND following positive SLN biopsy. SLN-positive patients with or without CLND were compared regarding important prognostic clinical and histological characteristics. Ten-year and 20-year survival curves for melanoma relapse and melanoma-specific survival (MSS) were determined by the Kaplan-Meier method and Cox proportional-hazards regression. We studied 258 patients who had micrometastases in their SLN biopsy. CLND was performed in 209 of 258 patients (81%). Hence, in 49 of 258 patients (19%) with SLN micrometastases, CLND was not performed. These patients did not significantly (p > 0.05) differ from patients with CLND in regard to age, gender, tumor thickness, tumor ulceration, capsule infiltration of SLN, or invasion level of SLN. On 10-year analysis, we did not observe a significantly increased risk for melanoma relapse and worse in MSS in patients who did not undergo CLND (hazard ratio: 1.1 (95% CI 0.67 to 1.7) and 1.1 (95% CI 0.67 to 1.9), respectively). On 20-year survival analysis, we confirmed that the risk of melanoma relapse and impaired MSS does not significantly increase in patients without CLND (hazard ratio: 1.2 (95% CI 0.8 to 1.9) and 1.3 (95% CI 0.8 to 2.3), respectively). On 10-year as well as 20-year multivariable follow-up analysis (including several important prognostic factors), Cox proportional-hazards regression showed that the status of CLND did not remain in the regression model (p > 0.1). Our 10-year data give conclusive support to previous investigations indicating that waiving CLND in patients with SLN micrometastases does not affect MSS. More importantly, our long-term follow-up data confirm for the first time the 10-year survival data of previous investigations.