Sentinel node studies in truncal melanoma: does an increased number of draining basins correlate with an increased risk of lymph metastasis?

Enhanced risk of multiple sentinel lymph node basins in truncal and head and neck melanoma

Introduction: Truncal and head and neck melanomas have a greater propensity to drain to multiple lymph node basins (MLNB) compared to extremity melanomas, which drain predominantly to a single lymph node basin (SLNB). The objective of this study was to compare the lymphatic drainage patterns and characteristics of truncal and head and neck melanoma, to assess their clinical usefulness in areas of unpredictable drainage. Methods: A retrospective review of 143 patients with head and neck or truncal melanoma from 2014–2018 treated at a tertiary referral hospital in Melbourne, Australia. Patients scheduled for a wide local excision (WLE) and SeNBx, and those whose initial biopsy results stated melanoma type, cell type and BT, were included. Patients were excluded if they underwent nodal biopsy alone. Results: We identified 95 patients with truncal and 48 with head and neck melanoma. Drainage to MLNB was significantly higher in the truncal melanoma group (36.8%) compared to the head and neck group (10.4%) (P = 0.001). Patients with drainage to MLNB had a higher positive sentinel node biopsy (SeNBx) rate compared to those with SLNB (40.0% verus. 12.6%, P <0.0001). Truncal melanomas that drained to MLNB were associated with a significantly higher Breslow thickness (2.1 versus. 1.5, P = 0.02), ulceration (40.6% vs. 20.7%, P = 0.043) and mitotic rate (3.0 versus. 2.0, P = 0.045) compared to equivalent melanomas that drained to SLNB. Conclusion: Patients with melanomas occurring in the trunk exhibit higher rates of drainage to MLNB compared to melanomas arising in the head and neck. Patients with drainage to MLNB also demonstrate a higher rate of positive SeNBx than those with SLNB drainage. This may represent more aggressive disease pathology or later diagnosis of lesions within these locations, or a lymphatic system that is more facilitatory of spread.

Impact of multiple lymphatic basin drainage in truncal melanoma patients

INTRODUCTION

In many patients with cutaneous melanoma that affects the trunk area, there is lymphatic drainage to multiple basins (MLBD). This study aimed to examine whether MLBD is associated with disease outcomes.

METHODS

Lymphatic mapping and sentinel lymph node (SLN) biopsy were performed in 161 patients with truncal melanoma. The number and location of draining nodal basins were established during the preoperative lymphoscintigraphy using technetium-99 m rhenium sulphide nanocolloid.

RESULTS

MLBD was present in 59 (37%) patients, and single lymphatic basin drainage (SLBD) in 102 (63%) patients. Patients with MLBD showed no increased risk for SLN metastasis compared to patients with SLBD (27% versus 29%, respectively). There was no significant difference in disease-free survival (DFS) between patients with MLBD and those with SLBD. Five-year DFS was 64% for patients with MLBD and SLBD. Multivariate analysis showed that the presence of ulceration (p = 0.01) was an independent predictor of SLN metastasis, while melanoma thickness (p = 0.01) and SLN metastasis (p = 0.01) were independent predictors of DFS. In patients with a negative SLN, five-year DFS was 74% for patients with MLBD and 73% for those with SLBD. Multivariate analysis showed that melanoma thickness (p = 0.00) was an independent predictor of DFS.

CONCLUSION

MLBD does not negatively impact the disease outcome in patients with truncal melanoma.

Time to Procedure, Nuclear Imaging and Clinicopathological Characteristics as Predictive Factors for Sentinel Lymph Node Metastasis in Cutaneous Melanoma: A Single-Center Analysis

OBJECTIVE

Sentinel lymph node (SLN) biopsy is a widely accepted staging procedure for cutaneous melanoma patients who are at risk of clinically occult nodal metastases. Numerous predictive factors for regional lymph node metastases have been identified; however, few have been found to be reproducibly significant. Also, the role of blue dye in identification was questioned in recent trials. Time to procedure was also found to be predictive of SLN positivity, but this was not confirmed in other studies. In our study, predictive factors for metastatic involvement of SLN were analyzed, together with the role of addition blue dye in imaging on detection rate and false-negative SLN rate. An impact of time interval to procedure on the rate of SLN positivity was also explored.

METHODS

Data analysis was done in 362 cutaneous melanoma patients who underwent lymphoscintigraphy and SLN biopsy at our institution from 2010 to 2016, with a median follow-up of 29 months (1-98 months). To delineate the relation of each variable (demographical, time to procedure, and clinical and pathological variables, as well as the presence of in-transit nodes, the number of draining basins, and SLN localization on scintigraphy) with positive SLN status, we used univariate logistic regression with odds ratios representing effect size.

RESULTS

Metastatic involvement SLN was found in 67 (18.8%) of 356 patients. Detection rate was similar with or without further intraoperative SLN identification with blue dye (98.8% vs 98.17%, P > 0.05). Time to procedure was not associated with higher SLN positivity rate (P > 0.05). In univariate analysis, Breslow thickness (P < 0.001), primary ulceration lesion (P = 0.001), and lymphovascular invasion (P = 0.006) were strongly correlated with SLN positivity, as well as the site of primary tumor (P = 0.024), tumor-infiltrating lymphocytes (TILs) (P = 0.021), and sex (P = 0.026). In multivariate analysis, Breslow thickness and TILs were found to be significant independent predictors of SLN status (P < 0.05).

CONCLUSIONS

Addition of blue dye did not improve SLN detection rate; time to procedure was not found to be associated with higher SLN biopsy positivity rates. Breslow thickness and TILs, as a marker of immune response to tumor, were consistently found to be significant independent predictors of SLN status.

Prognostic Value of Multiple Draining Lymph Node Basins in Melanoma: A Matched-Pair Analysis Based on the John Wayne Cancer Institute Experience

BACKGROUND

The prognostic significance of multiple draining basins is controversial in melanoma because analyses have not adequately controlled for standard prognostic variables. We hypothesized that an analysis based on prognostically matched pairs of patients with multiple versus single drainage basins would clarify any independent role of basin number.

STUDY DESIGN

We identified patients in our 40-year prospective database, who underwent preoperative lymphoscintigraphy, intraoperative sentinel node biopsy and wide local excision for cutaneous melanoma. Overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) were compared in patients with multiple versus single drainage basins after matching by age, sex, Breslow depth, primary site, and stage at diagnosis.

RESULTS

We identified 274 patients with multibasin drainage and 1,413 patients with single draining lymph node basins. Matching yielded 259 pairs (226 trunk, 27 head/neck, 6 extremity). Among matched pairs, multibasin drainage did not affect rates of lymph node metastasis (p = 0.84), OS (p = 0.23), DSS (p = 0.53), overall recurrence (p = 0.65), locoregional recurrence (p = 0.58), or distant recurrence (p = 1.0). Multivariable analysis linked higher T stage, ulceration, older age, and lymph node positivity to decreased DSS (p < 0.01) and DFS (p < 0.001). Number of drainage basins was not significant on univariable or multivariable analysis.

CONCLUSION

This analysis, the first to match for standard prognostic factors, suggests that multiplebasin drainage as identified by lymphoscintigraphy has no independent biological or prognostic significance in primary cutaneous melanoma.