Value of micromorphometric criteria of sentinel lymph node metastases in predicting further nonsentinel lymph node metastases in patients with melanoma

Abstract

Patients with metastases in the sentinel node (SN) are advised to undergo complete lymph node dissection, although the majority of them will have no further metastatic disease. Some of these patients undergo unnecessary surgery. In this study, we tried to predict the likelihood of further non-SN metastases on the basis of earlier published micromorphometric classifications of SN metastases. Metastases in the SN were re-evaluated on the basis of the microanatomic location of the lesions according to the Dewar's criteria, the S-classification of SN, and tumor burden in accordance with the Rotterdam criteria. The results of these classifications were correlated with the presence of further non-SN metastases. Specimens of 124 positive-SN basins and subsequent complete lymph node dissection were investigated. Further metastases in non-SNs were found in 30 lymph node basins (24.2%). All of the above-mentioned classification systems were significantly correlated with non-SN tumor status. Especially, in patients with SN metastases in subcapsular location, a maximum depth of invasion of less than 0.3 mm (stage I according to the S-classification) or metastases of less than 0.1 mm in diameter had a very low probability of further non-SN metastases (0-5%). The validity of earlier published classifications of SN metastases-based on the micromorphometric criteria in predicting non-SN status was confirmed. Especially, in patients with subcapsular metastases, SI stage metastases or metastases of less than 0.1 mm had a very low risk of further non-SN metastases.

Melanoma staging: Evidence‐based changes in the American Joint Committee on Cancer eighth edition cancer staging manual

“…There is significant and growing evidence that microscopic tumor burden in the SLN is prognostically important. [78][79][80][81][82][83][84][85][86][87][88][89][90] SLN tumor burden can be assessed by a variety of micromorphometric parameters, including the maximum size of the largest metastasis, the maximum subcapsular depth (also known as tumor penetrative depth 88 of the deposits and measured from the inner surface of the lymph node capsule to the deepest intranodal tumor cell), the microanatomic location of SLN tumor deposits, the percentage crosssectional area of the SLN that is involved, and the presence of extranodal extension. In various studies, one or more of these parameters has predicted survival in SLN-positive patients.…”

“…In various studies, one or more of these parameters has predicted survival in SLN-positive patients. [78][79][80][81][82][83][84][85][86][87][88][89][90] The impact of extent of SLN tumor burden (based on the greatest maximum dimension of the largest discrete, metastatic melanoma deposit) was assessed for the subset of patients with known SLN tumor burden in the IMDDP. In univariate analysis, increasing SLN tumor burden was associated with reduced MSS (Fig.…”

Five-year follow-up of 16 melanoma patients with a Starz I-involved sentinel node in whom completion lymph node dissection was omitted

“…Still, some investigators did report metastases in other nodes in patients with SI involvement. Fink et al [18] found that completion node dissection showed additional lymph node metastases in 4% of the SI patients. In their second study in 2004, Starz et al [6] noted that the incidence of additional positive lymph nodes was 11% in SI patients, 13% in SII patients and 53% in SIII patients.…”

“…To our knowledge, no other studies on the omission of completion lymph node dissection in the case of a SIpositive sentinel node have been published, but several investigators have studied the correlation between some form of tumour burden in the sentinel node and the presence of additional positive lymph nodes in the subsequent completion node dissection specimen [6,8,[18][19][20]. Younan et al [20] did not find additional tumour-positive lymph nodes in SI melanoma patients either, but they did find additional metastases in 11% of the SII patients and in 22% of the SIII patients (P = 0.04).…”

Completion lymph node dissection after a positive sentinel node

“…Subcapsular metastases represent approximately 20-30% of sentinel node positive patients and have better outcome than nonsubcapsular metastases [52,53 && ,62,66,70,82,83]. Patients with S1 metastases are about 30% of sentinel node positive patients and have improved survival over patients with S2 and, subsequently, S3 metastases [58,65,66,70,77,[82][83][84][85]. Patients with S1 metastases are about 30% of sentinel node positive patients and have improved survival over patients with S2 and, subsequently, S3 metastases [58,65,66,70,77,[82][83][84][85].…”