Meta‐analysis of sentinel lymph node positivity in thin melanoma (≤1 mm)

Abstract

Background Despite the lack of an established survival benefit of sentinel lymph node (SLN) biopsy, this technique has been increasingly applied in the staging of thin (≤1 mm) melanoma patients, without clear evidence to support this recommendation. We performed a meta-analysis to estimate the risk, potential predictors, and outcome of SLN positivity in this group of patients. Methods MEDLINE, EMBASE, and Cochrane databases were searched for rates of SLN positivity in patients with thin melanoma. The methodological quality of included studies was assessed using the MINORS criteria. Heterogeneity was assessed using Cochran’s Q-statistic, and publication bias was examined through funnel plot and Begg and Mazumdar’s method. Overall SLN positivity in thin melanoma patients was estimated using DerSimonial-Laird random effect method. Results 34 studies comprising 3,651 patients met inclusion criteria. The pooled SLN positivity rate was 5.6%. Significant heterogeneity among studies was detected (p=0.005). There was no statistical evidence of publication bias (p=0.21). 18 studies reported select clinical and histopathologic data limited to SLN positive patients (n=113). Among the tumors from these patients, 6.1% were ulcerated, 31.5% showed regression, and 47.5% were Clark’s level IV/V. Only 4 melanoma-related deaths were reported. Conclusion Relatively few patients with thin melanoma have a positive SLN. There are no clinical or histopathologic criteria which can reliably identify thin melanoma patients who might benefit from this intervention. Given the increasing diagnosis of thin melanoma, in addition to the cost and potential morbidity of this procedure, alternative strategies to identify patients at risk for nodal disease are needed.

Breslow Thickness, Clark Index and Ulceration Are Associated with Sentinel Lymph Node Metastasis in Melanoma Patients: A Cohort Analysis of 612 Patients

“…A large number of studies have tried to identify the criteria that may be used to indicate SLNB in thin melanomas, with conflicting results. Most of them were conducted on short retrospective heterogeneous cohorts [11,18,20,40,41]. In our study, we were not able to identify criteria associated with SLN metastasis in the subpopulation of patients with melanoma <1 mm.…”

Malignant Melanoma S3‐Guideline “Diagnosis, Therapy and Follow‐up of Melanoma”

“…Systematic search of the literature de-novo: [144][145][146][147][148][149][150] Strength of consensus: 100 %…”

“…However, the risk for a positive sentinel lymph node rises continuously with increasing thickness of the primary tumor [146,148,156,157]. In a meta-analysis of 34 studies, a tumor thickness of < 1 mm was associated with a positive sentinel lymph node in 5.6 % of patients, with values ranging from 0-14.3 % [150]. This large spread may likely be explained by the diversity of patient groups involved.…”

Five important dermatologic papers from the recent nondermatology literature

“…As a result of early melanoma detection, approximately 70% of patients with newly diagnosed melanomas have thin melanomas (≤1mm) [2]. While the use of sentinel lymph node biopsy (SLNB) has been increasingly prevalent in these cases, there "The study, which effectively controls for genetic variances in aging, confirms that aging, tobacco use and sun exposure have damaging effects on the skin.…”