Prediction of additional lymph node positivity and clinical outcome of micrometastases in sentinel lymph nodes in cutaneous melanoma: A multi-institutional study of 450 patients in Japan

Influencing factors associated with lymph node status in patients with cutaneous melanoma: An Asian population study

BACKGROUND

Sentinel lymph node (SLN) status is the predominant prognostic factor in patients diagnosed with clinically localized melanoma. The significance of completion lymph node dissection in patients with SLN metastasis is debatable. Not many studies have been conducted on acrallentiginous melanoma (ALM). This study aimed to characterize the prognostic factors of nodal positive ALM and confirm whether ALM patients can undergo the same treatment strategy as non-ALM patients in the Asian population.

METHODS

This is a retrospective review of patients who underwent surgery for cutaneous melanoma (CM) at Taipei Veterans General Hospital between January 1993 and December 2019. We investigated the risk factors for lymph node status. The association between clinicopathological factors and lymph node status of ALM and non-ALM patients was analyzed. Outcomes of completion lymph node dissection (CLND) performed following sentinel lymph node biopsy (SLNB) in the CM and ALM groups were compared.

RESULTS

A total of 197 patients were included in this study. ALM was the most common histological subtype, accounting for 66.5% of all the cases. Patients in the CM and ALM subgroups with metastatic SLN ( p = 0.012) or lymph nodes ( p < 0.001 and p = 0.001) exhibited higher mortality rate. Multivariate analysis showed that patients with clinical presentation of T4 category tumor ( p = 0.012) and lymphovascular invasion ( p = 0.012) had a significantly higher risk of positive lymph nodes. The overall survival of patients with lymph nodes metastasis was not associated with the performance of CLND.

CONCLUSION

Patients in the CM or ALM subgroups with metastatic SLNs or lymph nodes exhibited significantly poorer overall survival. Advanced Breslow thickness and lymphovascular invasion were independent predictive factors for CM and ALM patients with positive lymph node status. There was no significant difference in survival between CM and ALM patients following SLNB, regardless of CLND being performed.

Incidence and patterns of lymphatic drainage to the epitrochlear and popliteal sentinel lymph nodes in malignant melanoma of the distal extremities: a single-institution retrospective study

BACKGROUND

In most cutaneous melanomas of the distal extremity, sentinel lymph nodes (SLNs) are identified in the axillary or inguinal basin; however, they may be occasionally found in the epitrochlear or popliteal basins. The incidence and patterns of lymphatic drainage to the epitrochlear or popliteal SLNs are unclear.

METHODS

To clarify the incidence and clinical characteristics of melanoma draining to these ectopic SLNs, we performed a retrospective study of the patients with distal extremity melanoma who underwent SLN biopsy at the National Cancer Center Hospital between April 2010 and December 2017.

RESULTS

We identified 27 patients with melanoma of the distal upper extremity and 113 patients with melanoma of the distal lower extremity. All patients with distal upper and lower extremity melanomas had SLNs in the axillary and inguinal basins. Epitrochlear SLNs were found in 14.8% (4/27) of the patients with upper extremity melanoma, and the frequency increased by 36.4% (4/11) when the primary melanoma was located in the basilic vein area (P = 0.00188). Popliteal SLNs were found in 21.2% (24/113) of the patients with lower extremity melanoma, and the frequency increased by 37.9% (22/58) when the primary melanoma was located in the lesser saphenous vein area (P < 0.0001).

CONCLUSION

The incidence of SLNs identified in the epitrochlear or popliteal basin is not uncommon, and physicians need to be aware of these ectopic SLNs, especially when the primary melanoma is located in the basilic vein or lesser saphenous vein areas accordingly.

Sentinel lymph node biopsy in acral melanoma: A Korean single-center experience with 107 patients (2006-2018)

BACKGROUND

Sentinel lymph node biopsy (SLNB) of primary cutaneous melanoma as an important staging method has not been popularly undertaken in Korea and only a few studies with small patient numbers have been published.

AIM

We examined the clinical feasibility and overall outcomes of SLNB in acral melanoma (AM) of Korean in Kyungpook National University Hospital (KNUH) over the past 13 years.

METHODS

SLNB in AM patients during 2006-2018 were analyzed retrospectively for sentinel lymph node (SLN) harvesting rate, positivity rate, positivity-relevant overall survival (OS) and disease-free survival (DFS), and its side effects.

RESULTS

A total of 109 AM patients who underwent SLNB were enrolled. Harvested nodes were identified from 107 patients and SLN harvesting rate was 98.2%. The mean Breslow thickness (±standard deviation) was 3.38 ± 3.03 mm, and the proportion of ulcerated melanomas was 64%. Twenty-two (20.6%) had a tumor-positive SLN and, among them, 82% (18/22) underwent immediate complete lymph node dissection (CLND). The metastasis-positive nodal basin after CLND was detected in 16.7% of cases (3/18). Tumor-negative SLN cohorts showed significantly better OS and DFS than tumor-positive ones (P = 0.006 and P < 0.001 for each). Two side effects, one seroma and one lymphocele, were observed without major sequelae.

CONCLUSION

SLNB, crucial management of melanoma, proved its efficacy to predict patients' prognosis and could be performed successfully and safely in Korean AM patients by interdisciplinary cooperation between dermatology and other surgical departments. SLN(-) showed significantly better OS and DFS than SLN(+). Significant risk factors for DFS were Breslow thickness, the presence of ulceration and the presence of SLN metastasis. SLNB should be encouraged in order to stage melanoma accurately and direct the proper management in Korean AM.

The sentinel node invasion level (SNIL) as a prognostic parameter in melanoma

Sentinel lymph node (SN) tumor burden is becoming increasingly important and is likely to be included in future N classifications in melanoma. Our aim was to investigate the prognostic significance of melanoma infiltration of various anatomically defined lymph node substructures. This retrospective cohort study included 1250 consecutive patients with SN biopsy. The pathology protocol required description of metastatic infiltration of each of the following lymph node substructures: intracapsular lymph vessels, subcapsular and transverse sinuses, cortex, paracortex, medulla, and capsule. Within the SN with the highest tumor burden, the SN invasion level (SNIL) was defined as follows: SNIL 1 = melanoma cells confined to intracapsular lymph vessels, subcapsular or transverse sinuses; SNIL 2 = melanoma infiltrating the cortex or paracortex; SNIL 3 = melanoma infiltrating the medulla or capsule. We classified 338 SN-positive patients according to the non-metric SNIL. Using Kaplan-Meier estimates and Cox models, recurrence-free survival (RFS), melanoma-specific survival (MSS) and nodal basin recurrence rates were analyzed. The median follow-up time was 75 months. The SNIL divided the SN-positive population into three groups with significantly different RFS, MSS, and nodal basin recurrence probabilities. The MSS of patients with SNIL 1 was virtually identical to that of SN-negative patients, whereas outgrowth of the metastasis from the parenchyma into the fibrous capsule or the medulla of the lymph node indicated a very poor prognosis. Thus, the SNIL may help to better assess the benefit-risk ratio of adjuvant therapies in patients with different SN metastasis patterns.

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.

Use of Completion Lymph Node Dissection for Sentinel Lymph Node-Positive Melanoma

BACKGROUND

For patients with sentinel node-positive melanoma (SNPM), randomized trials, first reported in 2015, found no benefit for routine completion lymph node dissection (CLND) in selected patients. This study examines time trends in CLND and explores institutional and clinical factors associated with CLND.

STUDY DESIGN

The National Cancer Database was queried for patients older than 18 years from 2012 to 2016 with SNPM. A high-volume center was defined as >80th percentile for number of sentinel node procedures. Poisson regression assessed temporal trends and identified patient, pathologic, and institutional characteristics associated with CLND.

RESULTS

From 2012 to 2016, we identified 7,146 patients with SNPM. The proportion of patients undergoing CLND was steady in 2012 to 2014 (61% to 63%), but decreased to 57% in 2015 and 50% in 2016 (p < 0.0001). The proportion of patients with SNPM who underwent CLND decreased over time for both high- (66% to 52%; p < 0.0001) and lower-volume centers (55% to 45%; p = 0.06). Female sex (relative risk [RR] 0.97; p < 0.001) and increasing age (RR 0.98; p < 0.0001) were associated with lower likelihood of CLND. Increased Breslow depth (RR 1.015; p = 0.006), ulceration (RR 1.067; p = 0.02), and high-volume centers (RR 1.180; p < 0.0001) were associated with higher likelihood of CLND. Regional differences in likelihood of CLND were also present (p < 0.0001).

CONCLUSIONS

Completion lymph node dissection in SNPM decreased over time, with the greatest change in 2016. Several patient, pathologic, and institutional characteristics were associated with likelihood of CLND. As evidence supports close observation for selected patients, efforts should be undertaken to improve and standardize patient selection for CLND across institutions caring for patients with melanoma.

Correlation of Tumor Burden in Sentinel Lymph Nodes with Tumor Burden in Nonsentinel Lymph Nodes and Survival in Cutaneous Melanoma

PURPOSE

In patients with cutaneous melanoma, metastasis in a nonsentinel lymph node (non-SLN) is a strong independent adverse prognostic factor. However, patients with a tumor-involved SLN no longer routinely undergo completion lymph node dissection (CLND). We hypothesized that SLN tumor burden may predict non-SLN tumor burden.

EXPERIMENTAL DESIGN

We compared tumor burden parameters between SLN and non-SLN in patients with cutaneous melanoma who underwent SLN biopsy with a positive SLN during 2003 to 2008 at The University of Texas MD Anderson Cancer Center.

RESULTS

We identified 336 eligible patients with a positive SLN. Of these, 308 (92%) underwent CLND, and 35 (10%) had non-SLN metastasis. The median follow-up time was 6.0 years. For patients with maximum diameter of tumor in the SLN ≤2.0 mm, >2.0-5.0 mm, and >5.0 mm, non-SLN metastasis was detected in 5 of 200 patients (3%), 10 of 63 patients (16%), and 20 of 57 patients (35%), and the mean maximum diameters of the non-SLN tumor deposits were 0.09, 1.56, and 2.71 mm, respectively (P < 0.0001). The percentage of patients with both subcapsular and intraparenchymal non-SLN tumor was higher for patients with SLN tumor in both locations than for patients with SLN tumor in only one location (P < 0.0001). Extranodal extension in a non-SLN was more common in patients with extranodal extension in an SLN (P = 0.003).

CONCLUSIONS

In patients with cutaneous melanoma who undergo CLND, SLN tumor burden predicts non-SLN tumor burden. SLN tumor burden parameters provide accurate prognostic stratification independent of non-SLN status and should be considered for incorporation into future staging systems and integrated risk models.

Sentinel Lymph Node Biopsy Was Associated With Favorable Survival Outcomes For Patients With Clinically Node-Negative Asian Melanoma

Purpose

Sentinel lymph node biopsy (SLNB) is the standard management for clinically node-negative cutaneous melanoma patients. This study aimed to evaluate the role of SLNB in Taiwanese melanoma patients and in particular, patients with acral lentiginous melanoma (ALM).

Patients and methods

We retrospectively analyzed the clinicopathological characteristics and survival outcomes of the patients who underwent primary surgery followed by either SLNB or nodal observation at the Linkou Chang Gung Memorial Hospital from January 2000 to December 2011.

Results

Among the total of 209 patients, 127 underwent SLNB and 51 underwent nodal observation only after primary surgery. There were no significant differences in clinicopathological features between the two groups except that patients who underwent SLNB were older and had a higher rate of ALM than those under nodal observation. The median follow-up time was 43.5 months until July 2013. The patients who underwent SLNB had significantly better disease-free survival (DFS) (57.1 vs 18.7 months, p < 0.01) and melanoma-specific survival (MSS) (112.4 vs 45.2 months, p < 0.01) than those under observation. Improvement in DFS (HR: 0.51, p < 0.01) and MSS (HR: 0.60, p = 0.03) was observed even after adjusting for age and disease pathology by multivariate analysis. This benefit of clinical outcomes persisted in patients with ALM, Breslow thickness ≤2 mm, or no ulceration, but not in patients with non-ALM, Breslow thickness >2 mm, or ulceration.

Conclusion

SLNB was associated with favorable outcomes in patients with clinically node-negative cutaneous melanoma, particularly in Taiwanese patients with ALM, Breslow thickness ≤2 mm, and nonulcerated melanoma.

Prognostic factors for Taiwanese patients with cutaneous melanoma undergoing sentinel lymph node biopsy

BACKGROUND/PURPOSE

Sentinel lymph node biopsy (SLNB) is a standard procedure in the management of clinically node-negative melanoma. However, few studies have been performed on SLNB in Asia, which is an acral melanoma-prevalent area. This study evaluated the clinicopathologic prognostic factors of disease-free survival (DFS) and overall survival (OS) in Taiwanese patients with cutaneous melanoma who received wide excision and SLNB. The prognosis of patients with false-negative (FN) SLNB was also evaluated.

METHODS

Malignant melanoma cases were reviewed for 518 patients who were treated between January 2000 and December 2011. Of these patients, 127 patients with node-negative cutaneous melanoma who received successful SLNB were eligible for inclusion in the study.

RESULTS

The SLNB-positive rate was 34.6%. The median DFS was 51.5 months, and the median OS was 90.9 months at the median follow-up of 36.6 months. Multivariate analysis revealed that patients whose melanoma had a Breslow thickness greater than 2 mm had a significantly shorter DFS than patients whose melanoma had a Breslow thickness of 2 mm or less [hazard ratio (HR), 3.421; p = 0.005]. Independent prognostic factors of OS were a Breslow thickness greater than 2 mm (HR, 4.435; p = 0.002); nonacral melanoma (HR, 3.048; p = 0.001); and an age older than 65 years (HR, 2.819; p = 0.036). During the follow-up period, 13 of 83 SLN-negative patients developed a regional nodal recurrence. The SLNB failure rate was 15.7% and the FN rate was 22.8%. Compared to patients with a true-positive SLNB, patients with FN SLNB had a significantly shorter DFS (p = 0.001) but no significant difference in OS (p = 0.262).

CONCLUSION

Except for the pathologic subtypes, prognostic factors in Taiwan are similar to those used in other melanoma-prevalent countries. Identifying and closely monitoring patients at risk of nodal recurrence after a negative SLNB is important.

Atypical Spitzoid neoplasms: a review of potential markers of biological behavior including sentinel node biopsy

Atypical cutaneous melanocytic lesions, including those with Spitzoid features, can be difficult to categorize as benign or malignant. This can lead to suboptimal management, with potential adverse patient outcomes. Recent studies have enhanced knowledge of the molecular and genetic biology of these lesions and, combined with clinicopathological findings, is further defining their biological spectrum, classification, and behavior. Sentinel node biopsy provides important prognostic information in patients with cutaneous melanoma, but its role in the management of melanocytic lesions of uncertain malignant potential (MELTUMP) is controversial. This paper examines the role of molecular testing and sentinel node biopsy in MELTUMPs, particularly atypical Spitzoid tumors.

Long-term survival analysis and clinical follow-up in acral lentiginous malignant melanoma undergoing sentinel lymph node biopsy in korean patients

BACKGROUND

In cutaneous malignant melanoma (MM) with clinically uninvolved regional lymph nodes, sentinel lymph node (SLN) status is the most powerful indicator of both overall survival (OS) and disease-free survival (DFS). However, no studies on the long-term survival and clinical follow-up of Korean patients with acral lentiginous MM (ALM) undergoing SLN biopsy (SLNB) have been published.

OBJECTIVE

The purpose of this study was to investigate the clinical prognosis and long-term survival of Korean patients with ALM according to SLN status.

METHODS

Thirty-four ALM patients undergoing SLNB were included in this study. We evaluated clinical and histopathological follow-up data such as the stage of disease, treatment, recurrence, and metastasis, and analyzed OS and DFS according to SLN status.

RESULTS

The median follow-up time was 60.5 months (range 3~127 months). Positive SLNs were noted in 14 patients (41.2%). Patients with negative SLNs had better OS and DFS than those with positive SLNs (p<0.05). Increased Breslow thickness was associated with short OS and DFS (p<0.05), and female patients showed better DFS than male patients (p<0.05).

CONCLUSION

To our knowledge, this is the first study on the long-term survival and clinical follow-up of patients undergoing SLNB for ALM in Korea. Our findings show that SLN status is an important prognostic factor for predicting OS and DFS.

Limitation of indocyanine green fluorescence in identifying sentinel lymph node prior to skin incision in cutaneous melanoma

BACKGROUND

Although several reports have discussed the potential of the indocyanine green (ICG) fluorescence technique, its effectiveness and limitations have not been fully evaluated. For the accurate detection of sentinel lymph node (SLN) in cutaneous melanoma, which can arise in a wide variety of sites throughout the body, it is important to detect the SLN sites prior to skin incision. The purpose of this study was to evaluate the ICG fluorescence technique in the preoperative setting.

PATIENTS AND METHODS

We classified the detection process of SLN biopsy into three surgical stages: 'before skin incision,' 'after skin incision,' and 'ex vivo.' We retrospectively reviewed 93 node fields in 86 patients who underwent SLN biopsies using ICG and conventional techniques.

RESULTS

The detection rate using ICG at the 'before skin incision,' 'after skin incision,' and 'ex vivo' surgical stages were 63.4, 98.9, and 100 %, respectively. At the 'before skin incision' surgical stage, while lymphoscintigraphy (but not ICG) detected 33 node fields, ICG (but not lymphoscintigraphy) detected only four node fields. The detection rates varied from 100 % in the groin region drained from trunk to 15.8 % in the axillary region from upper limb. The factors that influenced the failure of ICG to identify hot SLNs were an axillary node field (p < 0.001) and a high body mass index (BMI) (p = 0.046).

CONCLUSION

For reliable identification of SLNs in cutaneous melanoma, the ICG fluorescence technique may offer little benefit for patients with axillary node field drained from upper limb, or high BMI.

Is complete lymph node dissection after a positive sentinel lymph node biopsy for cutaneous melanoma always necessary? A meta-analysis

BACKGROUND

The current recommendation for patients with cutaneous melanoma and a positive sentinel lymph node (SLN) biopsy is a complete lymph node dissection (CLND). However, metastatic melanoma is not present in approximately 80% of CLND specimens. A meta-analysis was performed to identify the clinicopathological variables most predictive of non-sentinel node (NSN) metastases when the sentinel node is positive in patients with melanoma.

METHODS

A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google scholar, Science Direct, and Web of Science. The search identified 54 relevant articles reporting the frequency of NSN metastases in melanoma. Original data was abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI).

FINDINGS

The pooled estimates that were found to be significantly associated with the high likelihood of NSN metastases were: ulceration (OR: 1.88, 95% CI: 1.53-2.31), satellitosis (OR: 3.25, 95% CI: 1.86-5.66), neurotropism (OR: 2.51, 95% CI: 1.39-4.53), >1 positive SLN (OR: 1.77, 95% CI: 1.2-2.62), Starz 3 (old) (OR: 1.83, 95% CI: 0.89-3.76), Angiolymphatic invasion (OR: 2.46, 95% CI: 1.34-4.54), extensive location (OR: 2.22, 95% CI: 1.74-2.81), macrometastases >2 mm (OR: 1.95, 95% CI: 1.61-2.35), extranodal extension (OR: 3.38, 95% CI: 1.79-6.40) and capsular involvement (OR: 3.16, 95% CI: 1.37-7.27). There were 3 characteristics not associated with NSN metastases: subcapsular location (OR: 0.51, 95% CI: 0.38-0.67), Rotterdam Criteria <0.1 mm (OR: 0.29, 95% CI: 0.17-0.50) and Starz I (new) (OR: 0.44, 95% CI: 0.22-0.91). Other variables including gender, Breslow thickness 2-4 mm and extremity as primary site were found to be equivocal.

INTERPRETATION

This meta-analysis provides evidence that patients with low SLN tumor burden could probably be spared the morbidity associated with CLND. We identified 9 factors predictive of non-SLN metastases that should be recorded and evaluated routinely in SLN databases. However, further studies are needed to confirm the standard criteria for not performing CLND.

Bortezomib/proteasome inhibitor triggers both apoptosis and autophagy-dependent pathways in melanoma cells

Generally, both endoplasmic reticulum (ER) stress and mitochondrial dysregulation are a potential therapeutic target of anticancer agents including bortezomib. The treatment of melanoma cells with bortezomib was found to induce apoptosis together with the upregulation of Noxa, Mcl-1, and HSP70 proteins, and the cleavage of LC3 and autophagic formation. Also, bortezomib induced ER-stress as evidenced by the increase of intracellular Ca(2+) release. In addition, bortezomib enhanced the phosphorylation of inositol-requiring transmembrane kinase and endonuclease 1α (IRE1α), apoptosis signal-regulating kinase 1 (ASK1), c-jun-N-terminal kinase (JNK) and p38, and the activation of the transcription factors AP-1, ATF-2, Ets-1, and HSF1. Bortezomib-induced mitochondrial dysregulation was associated with the accumulation of reactive oxygen species (ROS), the release of both apoptosis inducing factor (AIF) and cytochrome c, the activation of caspase-9 and caspase-3, and cleavage of Poly (ADP-ribose) polymerase (PARP). The pretreatment of melanoma cells with the inhibitor of caspase-3 (Ac-DEVD-CHO) was found to block bortezomib-induced apoptosis that subsequently led to the increase of autophagic formation. In contrast, the inhibition of ASK1 abrogated bortezomib-induced autophagic formation and increased apoptosis induction. Furthermore, the inhibition of JNK, of HSP70 also increased apoptosis induction without influence of bortezomib-induced autophagic formation. Based on the inhibitory experiments, the treatment with bortezomib triggers the activation of both ER-stress-associated pathways, namely IRE1α-ASK1-p38-ATF-2/ets-1-Mcl-1, and IRE1α-ASK1-JNK-AP-1/HSF1-HSP70 as well as mitochondrial dysregulation-associated pathways, namely ROS-ASK1-JNK-AP-1/HSF1-HS70, and AIF-caspase-3-PARP and Cyt.c, and caspase-9-caspase-3-PARP. Taken together, our data demonstrates for the first time the molecular mechanisms, whereby bortezomib triggers both apoptosis and autophagic formation in melanoma cells.