Analysis of Sentinel Node Biopsy and Clinicopathologic Features as Prognostic Factors in Patients With Atypical Melanocytic Tumors

Abstract

Background: Atypical melanocytic tumors (AMTs) include a wide spectrum of melanocytic neoplasms that represent a challenge for clinicians due to the lack of a definitive diagnosis and the related uncertainty about their management. This study analyzed clinicopathologic features and sentinel node status as potential prognostic factors in patients with AMTs. Patients and Methods: Clinicopathologic and follow-up data of 238 children, adolescents, and adults with histologically proved AMTs consecutively treated at 12 European centers from 2000 through 2010 were retrieved from prospectively maintained databases. The binary association between all investigated covariates was studied by evaluating the Spearman correlation coefficients, and the association between progression-free survival and all investigated covariates was evaluated using univariable Cox models. The overall survival and progression-free survival curves were established using the Kaplan-Meier method. Results: Median follow-up was 126 months (interquartile range, 104–157 months). All patients received an initial diagnostic biopsy followed by wide (1 cm) excision. Sentinel node biopsy was performed in 139 patients (58.4%), 37 (26.6%) of whom had sentinel node positivity. There were 4 local recurrences, 43 regional relapses, and 8 distant metastases as first events. Six patients (2.5%) died of disease progression. Five patients who were sentinel node–negative and 3 patients who were sentinel node–positive developed distant metastases. Ten-year overall and progression-free survival rates were 97% (95% CI, 94.9%–99.2%) and 82.2% (95% CI, 77.3%–87.3%), respectively. Age, mitotic rate/mm2, mitoses at the base of the lesion, lymphovascular invasion, and 9p21 loss were factors affecting prognosis in the whole series and the sentinel node biopsy subgroup. Conclusions: Age >20 years, mitotic rate >4/mm2, mitoses at the base of the lesion, lymphovascular invasion, and 9p21 loss proved to be worse prognostic factors in patients with ATMs. Sentinel node status was not a clear prognostic predictor.

Association of Sentinel Node Biopsy and Pathological Report Completeness with Survival Benefit for Cutaneous Melanoma and Factors Influencing Their Different Uses in European Populations

“…The survival benefit carried by SLNB for intermediate-thickness and thick melanomas found by our study is in line with population- [ 28 ] and hospital-based studies [ 31 ]. The finding that in comparison with thick melanoma the RER carried by SLNB decreased also for thin melanoma is consistent with recent studies indicating SLNB should be considered for selected high-risk patients, defined by features such as a high MI, ulceration, lympho-vascular invasion, tumor-infiltrating lymphocytes, or regression [ 31 , 32 , 33 ].…”

Clinical management of melanocytic tumours of uncertain malignant potential (MelTUMPs), including melanocytomas: A systematic review and meta‐analysis

“…The pooled estimate of SN‐positivity amongst patients undergoing SNB for MelTUMPs was 32%, yet only around 6% of the SN‐positive patients went on to develop further disease. The median tumour thickness information was not available for all the studies; however, it was 2.34 mm (ICR 2.20–2.49 mm) in the study of 238 patients by Maurichi et al, therefore, the tumours were predominantly of intermediate thickness 21 . In comparison, the positivity rate for intermediate‐thickness melanomas was 16% in the first Multicenter Selective Lymphadenectomy Trial (MSLT‐1); this was associated with a 5‐year disease‐free survival rate of 53.4% and a melanoma‐specific mortality rate of 26% for SN‐positive melanoma patients and a 5‐year melanoma‐specific mortality rate of 10.2 ± 1.3% for SNB negative melanoma patients 22 .…”

“…The median tumour thickness information was not available for all the studies; however, it was 2.34 mm (ICR 2.20-2.49 mm) in the study of 238 patients by Maurichi et al, therefore, the tumours were predominantly of intermediate thickness. 21 In comparison, the positivity rate for intermediate-thickness melanomas was 16% in the first Multicenter Selective Lymphadenectomy Trial (MSLT-1); this was associated with a 5-year disease-free survival rate of 53.4% and a melanoma-specific mortality rate of 26% for SNpositive melanoma patients and a 5-year melanoma-specific mortality rate of 10.2 ± 1.3% for SNB negative melanoma patients. 22 This is consistent with other cohort studies, such as the study by Rughani et al, in which the SN-positivity rate for 1.0-3.9 mm thick melanomas was 20.0% and the 5year melanoma-specific mortality rate was 33%.…”