Sentinel node biopsy for malignant melanoma: a staging procedure only?
ABSTRACT Sentinel node biopsy (SNB) is an established staging tool for malignant melanoma. It allows identification of patients with
metastatic disease at a very early stage and to collect accurate and complete prognostic information for these patients. Having
noted that in a relevant percentage of patients the sentinel node is the only site of metastases, some authors have postulated
a therapeutic role for SNB. In this paper, the possibility of a therapeutic role of SNB is evaluated. Relevant literature
on the topic has been analyzed. Several findings suggest that not all patients with a positive SNB have further lymph node
involvement. The prognostic indicators currently available do not significantly correlate with non-sentinel node (NSN) involvement.
It seems that more than morphological data of the tumor and of the lymph node metastasis, biologic markers may be investigated
to understand tumor behavior and predict NSN involvement. At present, SNB must still be considered a staging procedure only
and an appealing field of research to understand the behavior of melanoma. Better understanding of the biology of melanoma
and of the host’s immune response towards it may lead to identification of those patients with the sentinel node as the only
site of metastases.
KeywordsSentinel lymph node biopsy melanoma–Melanoma lymph node metastases–Melanoma prognosis–Prognostic false positivity–Melanoma lymphadenectomy
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ABSTRACT: Sentinel lymph node (SLN) positivity has been found to be strongly associated with a poor prognosis in melanoma. This large referral centre study was conducted: (i) to confirm the powerful prognostic value of SLN biopsy (SLNB); (ii) to correlate patient prognosis to the micromorphometric features of SLN metastasis in SLN-positive patients; and (iii) to correlate these micromorphometric features to the likelihood of positive completion lymph node dissection (CLND). SLNB was performed in 455 cases of primary melanoma between January 1999 and December 2004; for patients with positive SLN, the following micromorphometric features were registered: size of the largest metastasis (two diameters), depth of metastasis, number of millimetric slices involved, maximum number of metastases on a single section, presence of intracapsular lymphatic invasion and extracapsular spread. Kaplan-Meier survival curves were compared with the log-rank test; multivariate analysis was performed using a Cox regression model. Dependence of CLND status on micromorphometric features of SLN was assessed by the chi(2) test and predictive values of the different features were evaluated by multivariate analysis using a logistic regression model. A positive SLN was identified in 98 of our 455 cases. Survival was significantly shorter in SLN-positive patients than in SLN-negative patients. Extracapsular invasion was found to be an independent prognostic factor of disease-free survival; ulceration of the primary and the maximum diameter of the largest metastasis were identified as independent predictive factors of disease-specific survival. Age and the lowest diameter of the largest metastasis were identified as independent predictive criteria of positive CLND, whereas depth of metastasis was not. Positivity of CLND was not significantly associated with a worse prognosis. Our study confirms the previously demonstrated strong prognostic value of SLNB. It also confirms the relationship between tumour burden in the SLN (evaluated by the maximum diameter of the largest metastasis) and clinical outcome. We point out a new micromorphometric feature of SLN, which seems to be predictive of CLND status: the lowest diameter of the largest metastasis.British Journal of Dermatology 08/2007; 157(1):58-67. DOI:10.1111/j.1365-2133.2007.07937.x · 4.10 Impact Factor
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ABSTRACT: Sentinel node biopsy is now widely accepted as the most accurate prognostic indicator in melanoma, and is important in guiding management of patients with clinical stage I or II disease. Patients with a positive sentinel node have conventionally undergone completion lymphadenectomy (CLND) of the involved basin, but only 20% have involvement beyond the sentinel node, suggesting that CLND may be unnecessary for the other 80% of patients. This study seeks to identify criteria that might be used to be more restrictive in selecting those who should undergo CLND. A total of 146 patients were identified who had had a positive sentinel node biopsy for malignant melanoma. Their sentinel nodes and lymphadenectomy specimens were re-evaluated pathologically. The metastatic melanoma in each sentinel node was assessed according to its microanatomic location within the node (subcapsular, combined subcapsular and parenchymal, parenchymal, multifocal, or extensive), and this was correlated with the presence of involved nonsentinel nodes in the CLND. The depth of the metastases from the sentinel node capsule was also recorded. The metastatic deposits in the sentinel node were subcapsular in 26.0% of patients. None of these patients had any nonsentinel nodes involved on CLND. In the patients whose sentinel node metastases had a different microanatomic location, the rate of nonsentinel node involvement was 22.2% overall. The microanatomic location of metastases within sentinel nodes predicts nonsentinel lymph node involvement. In patients with only subcapsular deposits in the sentinel node, it is possible that CLND could safely be avoided.Journal of Clinical Oncology 09/2004; 22(16):3345-9. DOI:10.1200/JCO.2004.12.177 · 17.88 Impact Factor
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ABSTRACT: The aim of the present study was to determine whether micromorphometric features of positive sentinel lymph nodes (SLNs) from patients with melanoma are useful for predicting further nodal involvement in completion lymph node dissection (CLND) specimens. Of 986 patients with melanoma undergoing SLN biopsy between March 1992 and February 2001, 175 (17.7%) had at least 1 positive SLN and 140 had subsequent CLND specimens available for review. Further nodal involvement in CLND specimens was present in 24 (17.1%) of 140 patients. Of 8 micromorphometric features of the SLNs that were assessed, the presence of metastases in CLND specimens was correlated significantly with a tumor penetrative depth (maximum distance of melanoma cells from the inner margin of the SLN capsule) of more than 2 mm (P < .05), a deposit size of more than 10 mm2 (P < .01), the presence of melanoma cells in perinodal lymphatic vessels (P < .01), and the effacement of nodal architecture by metastatic melanoma cells (P < .05). Our results indicate that some morphologic features of melanoma metastases in SLNs predict the likelihood of further nodal involvement in CLND specimens.American Journal of Clinical Pathology 11/2004; 122(4):532-9. DOI:10.1309/TDWJ-TR15-TDM1-TG7Q · 3.01 Impact Factor