Single-Institution Experience in the Management of Patients with Clinical Stage I and II Cutaneous Melanoma: Results of Sentinel Lymph Node Biopsy in 240 Cases

Predictive Values of Pathological and Clinical Risk Factors for Positivity of Sentinel Lymph Node Biopsy in Thin Melanoma: A Systematic Review and Meta-Analysis

Background

The indications for sentinel lymph node biopsy (SLNB) for thin melanoma are still unclear. This meta-analysis aims to determine the positive rate of SLNB in thin melanoma and to summarize the predictive value of different high-risk features for positive results of SLNB.

Methods

Four databases were searched for literature on SLNB performed in patients with thin melanoma published between January 2000 and December 2020. The overall positive rate and positive rate of each high-risk feature were calculated and obtained with 95% confidence intervals (CIs). Both unadjusted odds ratios (ORs) and adjusted ORs (AORs) of high-risk features were analyzed. Pooled effects were estimated using random-effects model meta-analyses.

Results

Sixty-six studies reporting 38,844 patients with thin melanoma who underwent SLNB met the inclusion criteria. The pooled positive rate of SLNB was 5.1% [95% confidence interval (CI) 4.9%-5.3%]. Features significantly predicted a positive result of SLNB were thickness≥0.8 mm [AOR 1.94 (95%CI 1.28-2.95); positive rate 7.0% (95%CI 6.0-8.0%)]; ulceration [AOR 3.09 (95%CI 1.75-5.44); positive rate 4.2% (95%CI 1.8-7.2%)]; mitosis rate >0/mm2 [AOR 1.63 (95%CI 1.13-2.36); positive rate 7.7% (95%CI 6.3-9.1%)]; microsatellites [OR 3.8 (95%CI 1.38-10.47); positive rate 16.6% (95%CI 2.4-36.6%)]; and vertical growth phase [OR 2.76 (95%CI 1.72-4.43); positive rate 8.1% (95%CI 6.3-10.1%)].

Conclusions

The overall positive rate of SLNB in thin melanoma was 5.1%. The strongest predictor for SLN positivity identified was microsatellites on unadjusted analysis and ulceration on adjusted analysis. Breslow thickness ≥0.8 mm and mitosis rate >0/mm² both predict SLN positivity in adjusted analysis and increase the positive rate to 7.0% and 7.7%. We suggest patients with thin melanoma with the above high-risk features should be considered for giving an SLNB.

Micrometastases in cervical lymph nodes from patients with squamous carcinoma of the head and neck: should they be actively sought? Maybe

Techniques are now being developed, which allow ever smaller metastatic deposits in regional lymph nodes to be detected; the question is, should they be sought, or does their presence convey no additional information for treatment of head and neck carcinoma patients at this time? Preliminary findings have suggested that the presence of micrometastases may carry with it some prognostic information, and as a consequence, the search for micrometastases would, for the foreseeable future, appear to be a fertile ground for investigation. To bring some uniformity to this project, it is suggested that these definitions be adopted: a micrometastasis measures greater than 0.2 mm but less than 2.0 mm in diameter, and smaller deposits should be designated as isolated tumor cells, which, in turn, are subdivided into those isolated tumor cells detected by light microscopy, immunohistochemistry, or molecular methods. At this juncture, the import of such micrometastases remains in the realm of the clinical investigator--it remains an open question whether the identification of micrometastases (however they may ultimately come to be defined) will prove to have an impact on the care of head and neck cancer patients.

Prognostic significance of molecular staging study of sentinel lymph nodes by reverse transcriptase-polymerase chain reaction for tyrosinase in melanoma patients

BACKGROUND

We performed this study to evaluate the clinical effect of microscopic and submicroscopic metastases in sentinel lymph nodes (SLNs) from patients with early-stage melanoma.

METHODS

Patients with confirmed cutaneous melanoma (American Joint Committee on Cancer stages I and II) underwent standard lymphoscintigraphy and SLN biopsy. Serial sections were divided between routine histopathology with hematoxylin and eosin plus immunohistochemistry for HMB-45 and molecular analysis by nested reverse transcriptase-polymerase chain reaction (RT-PCR) assay for tyrosinase (using beta-actin as a control).

RESULTS

Of 180 patients analyzed (318 SLNs), 38 (21%) patients had positive SLN(s) by routine hematoxylin and eosin and immunohistochemistry (microscopic disease; group 1), and 142 (79%) had negative histological results. Analysis by RT-PCR detected tyrosinase in at least 1 SLN from 124 (69%) patients. Among patients with histologically negative SLN(s), tyrosinase was detected in 86 (48%) patients (submicroscopic disease; group 2), whereas 40 (22%) patients had negative results by both histology and RT-PCR (group 3). Sixteen (9%) patients had histologically negative SLNs and ambiguous RT-PCR results (group 4). Among 138 patients in the analysis of recurrence (mean follow-up, 45 months), only 18 patients had a recurrence: 11 (31%) of 35 in group 1, 5 (10%) of 51 in group 2, and 2 (5%) of 37 in group 3. No recurrences were seen in group 4. Only group 1 had a significantly shorter disease-free survival and overall survival compared with the other groups.

CONCLUSIONS

After a long follow-up period, molecular upstaging by tyrosinase RT-PCR failed to detect a subgroup of patients with an increased probability of recurrence.