Clinicopathological significance of sentinel node biopsy in Japanese patients with cutaneous malignant melanoma

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.

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.

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.

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.

Applicability of radiocolloids, blue dyes and fluorescent indocyanine green to sentinel node biopsy in melanoma

Patients with primary cutaneous melanoma underwent sentinel node (SN) mapping and biopsy at 25 facilities in Japan by the combination of radiocolloid with gamma probe and dye. Technetium-99m ((99m)Tc)-tin colloid, (99m)Tc-phytate, 2% patent blue violet (PBV) and 0.4% indigo carmine were used as tracers. In some hospitals, 0.5% fluorescent indocyanine green, which allows visualization of the SN with an infrared camera, was concomitantly used and examined. A total of 673 patients were enrolled, and 562 cases were eligible. The detection rates of SN were 95.5% (147/154) with the combination of tin colloid and PBV, 98.9% (368/372) with the combination of phytate and PBV, and 97.2% (35/36) with the combination of tin colloid or phytate and indigo carmine. SN was not detected in 12 cases by the combination method, and the primary tumor was in the head and neck in six of those 12 cases. In eight of 526 cases (1.5%), SN was detected by PBV but not by radiocolloid. There were 13 cases (2.5%) in which SN was detected by radiocolloid but not by PBV. In 18 of 36 cases (50%), SN was detected by radiocolloid but not by indigo carmine. Concomitantly used fluorescent indocyanine green detected SN in all of 67 cases. Interference with transcutaneous oximetry by PVB was observed in some cases, although it caused no clinical trouble. Allergic reactions were not reported with any of the tracers. (99m)Tc-tin colloid, (99m)Tc-phytate, PBV and indocyanine green are useful tracers for SN mapping.