Is incisional biopsy of melanoma harmful?

Background: In the era of sentinel lymph node (SLN) biopsy, there has been concern that manipulation, injection, and massage of intact primary melanomas (after incisional or shave biopsy) could lead to an artifactual increased rate of SLN micrometastases or an actual increased risk of recurrence. The aim of this study was to evaluate the difference in the incidence of SLN metastasis, locoregional recurrence (LRR), disease-free survival (DFS), distant disease-free survival (DDFS), or overall survival (OS) for patients who undergo excisional versus incisional versus shave biopsy. Methods: Analysis of database from a multicenter prospective randomized study from centers across the United States and Canada. Eligible patients were 18 to 71 years old, with cutaneous melanoma ≤1.0 mm Breslow thickness. All patients underwent SLN biopsy using blue dye and radioactive colloid injection. SLNd were evaluated by serial histological sections with S100 immunohistochemistry. Statistical analysis was performed using univariate and multivariate analyses with a significance level of P < .05; survival analysis was performed by the Kaplan-Meier method with the log-rank test. Results: A total of 2,164 patients were evaluated; 382 patients were excluded for lack of biopsy information. Positive SLNs were found in 220 of 1,130 (19.5%), 58 of 281 (20.6%), and 67 of 354 (18.9%) of patients with excisional, incisional, or shave biopsy, respectively (no significant difference). There were significant differences among the 3 biopsy types in ulceration (P = .018, χ²) and regression (P = .022, χ²); there were no differences in age, gender, Breslow thickness, Clark level, lymphovascular invasion, tumor location, or histologic subtype. Biopsy type did not significantly affect LRR, DFS, DDFS, or OS. Conclusions: The concern that incomplete excision of primary melanomas may result in an increased incidence of SLN micrometastases, artifactual or real, is unfounded. Similarly, there is no evidence that biopsy type adversely affects locoregional or distant recurrence. Although shave biopsy is generally discouraged because it may lead to inaccurate tumor thickness measurements, it does not appear to affect overall patient outcome.