Indications for lymphatic mapping and sentinel lymphadenectomy in patients with thin melanoma (Breslow thickness < or =1.0 mm).
BACKGROUND
Patients with thin (Breslow thickness < or =1.0 mm) melanoma have a good prognosis (5-year survival >90%). Consequently, the added benefit of lymphatic mapping and sentinel lymphadenectomy (LM/SL) in these patients is controversial. We hypothesize that LM/SL with a focused examination of the sentinel node (SN) will detect a significant number of SN metastases in patients with thin melanoma and that certain clinical or histopathologic factors may serve as predictors of SN tumor involvement.


METHODS
Over 6 years, 349 patients with melanoma underwent LM/SL and were prospectively entered into an institutional review board (IRB)-approved database. LM/SL was performed with a combined radiotracer and blue dye technique. SNs were serially sectioned, and each section was examined by a dermatopathologist at multiple levels with hematoxylin and eosin as well as immunohistochemical stains.


RESULTS
One hundred forty-six patients (42%) had a melanoma with Breslow thickness < or =1.0 mm; six (4%) of these 146 patients had a tumor-involved SN. On multivariate analysis, none of the clinical or histopathologic factors examined were significantly associated with SN tumor involvement in patients with thin melanoma. Completion lymphadenectomy was performed on all patients with a tumor-involved SN. None of the patients had non-SN tumor involvement.


CONCLUSIONS
The incidence of SN tumor involvement in patients with thin melanoma is considerable. Although we were unable to identify predictors of SN tumor involvement in patients with thin melanoma, efforts to identify predictors of SN tumor involvement should continue. Until better predictors are identified, we continue to advocate offering LM/SL to patients with thin melanomas who demonstrate clinical or histopathologic characteristics that have historically been associated with an increased risk of recurrence and mortality.
Stitzenberg
Karyn B
KB
Division of Surgical Oncology, Department of Surgery, 3010 Old Clinic Building, CB#7213, University of North Carolina, Chapel Hill, NC 27599-7213, USA.
Groben
Pamela A
PA
Stern
Stacey L
SL
Thomas
Nancy E
NE
Hensing
Thomas A
TA
Sansbury
Leah B
LB
Ollila
David W
DW
D000328:Adult; D000368:Aged; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology*