Sentinel lymph node biopsy in patients with malignant melanoma: analysis of post-operative complications

The Characteristics of Sentinel Lymph Node Biopsy in Cutaneous Melanoma and the Particularities for Elderly Patients-Experience of a Single Clinic

BACKGROUND

Melanoma is a malignant tumor that determines approximately 80% of deaths as skin cancer-related. The sentinel lymph node (SLN) represents the first filter of tumor cells toward systemic dissemination. The primary objective was to outline the surgical specifics of the sentinel lymph node biopsy (SLNB) technique, correlate the location of the lymph node with the radiotracer load, and identify the characteristics of older patients.

METHODS

In this prospective study, 122 cases of malignant melanoma needing SLNB technique were included, between June 2019 and November 2022, resulting in 162 lymph nodes removed.

RESULTS

Patients' mean age was 54.3 ± 14.4 years old, the prevalence of 70 years and older being 20.5%. The rate of positive SLN was 24.6%, with a single drainage in 68.9% of cases. The frequency of seroma was 14.8%, while reintervention 1.6%. The inguinal nodes had the highest preoperative radiotracer load (p = 0.015). Patients 70 years old or older had significantly more advanced-stage melanoma (68.0% vs. 45.4%, p = 0.044, OR = 2.56) and a higher rate of positive SLN (40.0% vs. 20.6%, p = 0.045,OR = 2.57). Melanoma of the head and neck was more common among older individuals (32.0% vs. 9.3%, p = 0.007,OR = 4.60).

CONCLUSIONS

The SLNB has a low rate of surgical complications and the positivity of SLN is not related to radiotracer load. Elderly patients are at risk for head and neck melanoma, have more advanced stages, a higher SLN positivity, and a greater rate of surgical complications.

Incidence and risk factor analysis of complications after sentinel node biopsy for penile cancer

BACKGROUND

Surgical staging is recommended in intermediate to high risk clinically node negative (cN0) penile cancer (PeCa). Because (modified) inguinal lymph node dissection (ILND) is associated with high morbidity, dynamic sentinel node biopsy (DSNB) was introduced with the aim to reduce morbidity while maintaining diagnostic accuracy.

OBJECTIVE

To determine the incidence and types of complications after DSNB and identify risk factors for the occurrence of postoperative complications.

PATIENTS AND METHODS

We evaluated 644 PeCa patients (1284 DSNB procedures) with at least one cN0 groin who underwent DSNB between 2011 and 2020 at a single high-volume centre. 30-day and 30-90-day postoperative complications were collected according to the modified Clavien Dindo classification and the standardized methodology proposed by the European Association of Urology panel. Univariable and multivariable generalized linear mixed models were used to identify risk factors for the occurrence of complications per groin.

RESULTS

A 30-day postoperative complication occurred in 14% of groins (n=186), of which 94% were mild to moderate. Wound infection and lymphocele formation were most common. 30-90-day postoperative complications occurred in 3.4% of the groins, all of which were mild or moderate (grade 1-2). The number of removed LNs per groin was the main independent predictor for any 30-day complications and grade≥2 complications (OR 1.40; p<0.001). An increase in the probability of postoperative complications with the number of LNs removed was observed after accounting for all confounders.

CONCLUSIONS

Despite being less morbid than (modified) ILND, DSNB is still associated with a considerable risk of mild to moderate postoperative complications. This risk increases with an increasing number of LNs removed. Further procedural refinement aimed at removing the true sentinel node(s) only, may help further reduce the morbidity of surgical staging in PeCa.

Percutaneous contrast-enhanced ultrasound for localization and qualitative diagnosis of sentinel lymph nodes in cutaneous malignant melanoma of lower extremities: a preliminary study

Background

To explore the feasibility of sentinel lymph node (SLN) tracing by percutaneous contrast-enhanced ultrasound (pCEUS) in patients with cutaneous malignant melanoma (CMM) and the ability to enhance patterns of SLNs in diagnosing lymph nodes (LNs) metastases.

Methods

Fifty-three patients with CMM of the lower extremities treated at our hospital were included in the study. All the participants received pCEUS preoperatively. The enhanced lymphatic channels (LCs) and associated SLNs were observed and tracked in real-time. The number of enhanced LCs and enhancing patterns of SLNs were recorded. Subsequently, SLNs localized by pCEUS were pathologically examined.

Results

Of the 53 cases, SLNs were successfully localized by pCEUS in 48 cases. In total, there were 59 detected SLNs averaging 1.23±0.42 SLNs per case. The main lymphatic drainage patterns (LDPs) were the following: one enhanced LC pointed to one or more than one SLN, and multiple enhanced LCs pointed to one or multiple SLNs. There were four enhancing patterns of SLNs (uniform, annular, uneven, and no enhancement), among which the first two were considered benign nodes, while the latter two were considered metastatic nodes. With pathological results as the gold standard, the diagnostic sensitivity and specificity by pCEUS were 90.9% and 75.0%, respectively.

Conclusions

Contrast-enhanced ultrasound (US) is a feasible approach for SLN identification in patients with CMM of the lower extremities. Enhancing patterns of SLNs may help predict metastasizing SLNs. This novel method may be a promising technique for clinical application.

Validation of a clinicopathological and gene expression profile model to identify patients with cutaneous melanoma where sentinel lymph node biopsy is unnecessary

BACKGROUND

In patients with cutaneous melanoma, sentinel lymph node biopsy (SLNB) serves as an important technique to asses disease stage and to guide adjuvant systemic therapy. A model using clinicopathologic and gene expression variables (CP-GEP; Merlin Assay) has recently been introduced to identify patients that may safely forgo SLNB. Herein we present data from an independent validation cohort of the CP-GEP model in Swedish patients.

METHODS

Archival histological material (primary melanoma tissue) from a prospectively collected cohort of 421 consecutive patients with pT1-T4 melanoma undergoing SLNB between 2006 and 2014 was analyzed using the CP-GEP model. CP-GEP combines Breslow thickness and patient age with the expression levels of eight genes from the primary melanoma. Stratification is based on their risk for nodal metastasis: CP-GEP Low Risk or CP-GEP High Risk.

RESULTS

The SLNB positivity rate was 13%. Of 421 primary melanomas, the CP-GEP model identified 86 patients as having a low risk for nodal metastasis. In patients with pT1-2 melanomas, the SLNB reduction rate was 35.4% (95% CI: 29.4-41.8) with a negative predictive value (NPV) of 96.5% (95% CI: 90.0-99.3). Among patients with pT1-3 melanomas, CP-GEP suggested a SLNB reduction rate of 24.0% (95% CI: 19.7-28.8) and a NPV of 96.5% (95% CI: 90.1-99.3). Only one of 118 pT3 tumors was classified as CP-GEP Low Risk, and all pT4 tumors were classified as being high risk for nodal metastasis.

CONCLUSION

This study demonstrates that CP-GEP can identify patients with a low risk for nodal metastasis. Patients with pT1-2 melanomas have the highest clinical benefit from using the test, where 35% of the patients could forgo a SLNB procedure.

Proposed quality performance indicators of sentinel lymph node biopsy for cutaneous melanoma

BACKGROUND

Melanoma is a leading cause of morbidity and mortality in Australia and New Zealand. New Zealand has the highest melanoma incidence in the world alongside Australia at 54 per 100 000 persons. The aim of this study is to conduct a retrospective quality audit of sentinel lymph nodal biopsy (SLNB) practices from 2007 to 2019 of a high-volume melanoma surgeon. Primary outcome was false negative rate (FNR). Secondary outcomes were sentinel node (SN) identification and removal rate, and complication rates.

METHODS

A database was maintained, containing n = 553 consecutive SLNB's for cutaneous melanoma from 31 August 2007 to 31 August 2019. Patient characteristics and details of the primary lesion, sentinel lymph node biopsy, recurrence and complications were recorded.

RESULTS

SN's were successfully identified in 444 (99.6%) out of 446 patients with an FNR of 9.1%. Positive SN's were identified in 70 (12.7%) SLNB's. Complications occurred in 76 out of 553 (13.7%) SLNB's. A review of internationally published literature reveals an SN identification rate of 94.4-99.5% with an FNR of 4.0-37.5%. SLNB is the best staging tool for melanoma and gives potential access to adjuvant systemic treatment if >1 mm deposits are found. It is a day-stay procedure with a low-complication rate.

CONCLUSION

SLNB is a safe and reliable procedure utilized for cutaneous melanoma. We propose our data should be used alongside international SN series to establish Quality Performance Indicators to improve melanoma management.

The Devil's in the Details: Discrepancy Between Biopsy Thickness and Final Pathology in Acral Melanoma

PURPOSE

We hypothesized that initial biopsy may understage acral lentiginous melanoma (ALM) and lead to undertreatment or incomplete staging. Understanding this possibility can potentially aid surgical planning and improve primary tumor staging.

METHODS

A retrospective review of primary ALMs treated from 2000 to 2017 in the US Melanoma Consortium database was performed. We reviewed pathology characteristics of initial biopsy, final excision specimens, surgical margins, and sentinel lymph node biopsy (SLNB).

RESULTS

We identified 418 primary ALMs (321 plantar, 34 palmar, 63 subungual) with initial biopsy and final pathology results. Median final thickness was 1.8 mm (range 0.0-19.0). There was a discrepancy between initial biopsy and final pathology thickness in 180 (43%) patients with a median difference of 1.6 mm (range 0.1-16.4). Final T category was increased in 132 patients (32%), including 47% of initially in situ, 32% of T1, 39% of T2, and 28% of T3 lesions. T category was more likely to be increased in subungual (46%) and palmar (38%) melanomas than plantar (28%, p = 0.01). Among patients upstaged to T2 or higher, 71% had ≤ 1-cm margins taken. Among the 27 patients upstaged to T1b or higher, 8 (30%) did not have a SLNB performed, resulting in incomplete initial staging.

CONCLUSIONS

In this large series of ALMs, final T category was frequently increased on final pathology. A high index of suspicion is necessary for lesions initially in situ or T1 and consideration should be given to performing additional punch biopsies, wider margin excisions, and/or SLNB.

High level of TILs is an independent predictor of negative sentinel lymph node in women but not in men

Factors that are most associated with positive lymph node status in melanoma are Breslow thickness and ulceration. However, there are other factors that have been little explored and could help in the identification of "at risk patients" harbouring occult metastasis. The objective of this study was to determine whether intensity of tumour-infiltrating lymphocytes (TILs) in a cohort study (N = 4133) is an independent predictor of sentinel lymph node (SLN) status in patients with primary cutaneous melanoma. Of the patients with cutaneous melanoma who resulted negative for nodal metastasis, 50.7% had moderate/marked TILs versus 27.7% among those patients who resulted positive for nodal metastasis. In the multivariate analysis, controlling for sex, age, mitotic rate, ulceration and Breslow, high levels of TILs in primary invasive melanoma was associated with a lower risk of developing SLN metastasis (OR 0.46; 95% CI 0.23-0.95, p = 0.037). When the analysis was stratified by sex, the protective effect of moderate/marked TIL remained only for women (OR 0.30; 95% CI 0.10-0.93, p = 0.037) but not for men (OR 0.51; 95% CI 0.19-1.34, p = 0.172). Other independent predictors of negative lymph node were low Breslow thickness (≤ 2.0 mm) and low mitotic rate. Besides predicting a negative lymph node response, TILs were also associated with a decreased risk of 10-year mortality among females with positive lymph node. Our findings suggest that high level of TILs is an independent predictor of negative SLN status among women. Further research is warranted to confirm our findings.