Sentinel lymph node tumor load: an independent predictor of additional lymph node involvement and survival in melanoma.
BACKGROUND
Even though 60% to 80% of melanoma patients with a positive sentinel lymph node (SLN) have no positive additional lymph nodes (ALNs), all these patients are subjected to an ALN dissection (ALND) with its associated morbidity. The aim of this study was to predict the absence of ALN metastases in patients with a positive SLN by using features of the primary melanoma and SLN tumor load.


METHODS
Of 71 SLN-positive patients, 52 had metastasis limited to the SLN (group 1), and 19 had > or =1 positive ALN after ALND (group 2). The tumor load of the SLN was assessed by measuring the total surface area by computerized morphometry. Breslow thickness, ulceration and lymphatic invasion of the primary tumor, and total SLN metastatic area were tested as covariates predicting the absence of positive ALNs.


RESULTS
The mean SLN metastatic area was 1.18 mm(2) (group 1) and 3.39 mm(2) (group 2) (P = .003) and was the only significant and independent factor after multivariate analysis (P = .02). None of the patients with both a Breslow thickness <2.5 mm and an SLN metastatic area <.3 mm(2) had a positive ALN.


CONCLUSIONS
SLN metastatic area can be used to predict the absence of positive ALNs in melanoma patients. In this study, patients with a Breslow thickness <2.5 mm and an SLN tumor load <.3 mm(2 )seemed to have no positive ALN and had excellent survival. We hypothesize that this subgroup might not benefit from ALND. Prospective larger trials, using this model and randomizing between ALND and no ALND, should confirm this hypothesis.
Vuylsteke
Ronald J C L M
RJ
Department of Surgical Oncology, VU University Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
Borgstein
Paul J
PJ
van Leeuwen
Paul A M
PA
Gietema
Hester A
HA
Molenkamp
Barbara G
BG
Statius Muller
Markwin G
MG
van Diest
Paul J
PJ
van der Sijp
Joost R M
JR
Meijer
Sybren
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D008962:Models, Theoretical; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology*