Prognostic value of sentinel lymph node biopsy according to Breslow thickness for cutaneous melanoma

Abstract

Background: Sentinel lymph node (SLN) biopsy is widely performed for melanoma with certain histologic parameters and offers important prognostic and staging information. Breslow thickness (BT) by itself also provides meaningful prognostic information.

Objective: To evaluate whether SLN status provides prognostic information independent from that which is already provided by BT.

Methods: We conducted a retrospective cohort study of 896 patients who underwent SLN biopsy for primary cutaneous melanoma. Stratified analysis of the impact of SLN status within BT groups (0.01-1 mm, 1.01-2.00 mm, 2.01-4.00 mm, and >4.00 mm) was performed. In addition, a Cox proportional hazard model was fit to evaluate the interaction between BT unadjusted and then adjusted for SLN status to determine whether predictive ability is improved.

Results: Having a negative SLN did not confer a statistically significant survival advantage for any BT subgroup (P = .54, .075, .17, and .95 for subgroups 0.01-1 mm, 1.01-2.00 mm, 2.01-4.00 mm, and >4.00 mm, respectively). In multivariate analysis, SLN status did not demonstrate independent prognostic ability over that of BT alone (P = .067).

Limitations: Retrospective study, single institution.

Conclusion: Our data suggest that SLN status does not offer better prognostic information for patients than BT alone.

Keywords: Breslow thickness; melanoma; melanoma prognosis; sentinel lymph node biopsy.