Predicting sentinel node status in AJCC stage I/II primary cutaneous melanoma.
BACKGROUND
Sentinel lymph node (SLN) status is an important prognostic factor for survival for patients with primary cutaneous melanoma. To address the issue of selecting patients at high and low risk for a positive SLN, prognostic factors were sought that predict SLN involvement by examining characteristics of both the primary tumor and the patient within the context of a biological model of melanoma progression.


METHODS
The study included 682 patients with primary vertical growth phase (VGP) melanoma and no clinical evidence of metastatic disease who underwent SLN biopsy (1995-2003). Logistic regression and classification tree analyses were used to investigate the association between SLN positivity and Breslow thickness, Clark level, tumor infiltrating lymphocytes (TIL), ulceration, mitotic rate (MR), lesion site, gender, and age. RESULTS.: In all, 88 of the 682 patients had > or =1 positive SLN (12.9%). In the multivariate analysis, MR, TIL, and thickness were found to be independent prognostic factors for SLN positivity. In the classification tree, four different risk groups were defined, ranging from minimal risk (2.1%) to high risk (40.4%). In lesions < r =2.0 mm, MR was important in risk-stratifying patients, and in lesions >2.0 mm TIL was important.


CONCLUSIONS
By incorporating biologically based variables such as VGP, TIL, and MR along with thickness into a prognostic model, both patients at high risk and minimal risk for SLN positivity can be identified. If validated, this model can be used in patient management and trial design to select patients to undergo or be spared SLN biopsy.
Kruper
Laura L
LL
Melanoma Program of the Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. laura.kruper@uphs.upenn.edu
Spitz
Francis R
FR
Czerniecki
Brian J
BJ
Fraker
Douglas L
DL
Blackwood-Chirchir
Anne
A
Ming
Michael E
ME
Elder
David E
DE
Elenitsas
Rosalie
R
Guerry
Dupont
D
Gimotty
Phyllis A
PA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000473:pathology*; D008875:Middle Aged; D008962:Models, Theoretical; D009367:Neoplasm Staging / Q000379:methods; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology*