Results of sentinel lymph node biopsy in patients with thin melanoma.
BACKGROUND
Sentinel lymph node (SLN) biopsy has been shown to be a highly accurate method of staging nodal basins in melanoma patients. Although this technique is widely accepted in patients with intermediate-thickness tumors, it is unclear what the indications are for thin (< or = 1 mm) melanoma.


METHODS
From May 1991 to October 2004, 223 patients with thin melanoma underwent SLN biopsy at Memorial Sloan-Kettering Cancer Center. Most patients with thin melanoma were selected for the procedure because of high-risk clinicopathologic features.


RESULTS
Nodal metastases were found in eight patients (3.6%) who underwent SLN biopsy. All positive SLNs were found in patients with > or = .75 mm-thick and Clark level IV melanoma (8 of 114; 7%). Age, sex, tumor location, thickness, Clark level, ulceration, regression, tumor-infiltrating lymphocytes, mitotic rate, and number of mapped nodal basins were not predictive of positive SLNs (chi(2); P = not significant). With a median follow-up of 25 months, there have been no recurrences or deaths in patients with melanoma < .75 mm. Six patients have had regional and/or systemic recurrences (2.7%), only one of whom had a positive SLN. Three patients have died of melanoma; all had negative SLNs.


CONCLUSIONS
Nodal metastasis in thin melanoma is uncommon, especially in patients with < .75 mm and Clark level II or III melanoma. In our experience, no single clinicopathologic factor was predictive of nodal metastases. The prognostic implications of positive SLNs in thin melanoma remain undefined.
Wong
Sandra L
SL
Department of Surgery, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10021, USA.
Brady
Mary S
MS
Busam
Klaus J
KJ
Coit
Daniel G
DG
D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology*