3.2 Biopsy findings associated with residual melanoma on wide local excision
We first sought to identify variables of interest from the biopsy pathology report associated with whether there would be residual melanoma at the time of wide local excision. Of the 67 patients whose surgical pathology report identified presence or absence of residual melanoma, 31 (46.3%) did not have residual melanoma and 36 (53.7%) did. The 10 variables listed in Table 3 were used as predictors in a univariable Firth logistic regression model. Of these, only involvement of the deep margins at biopsy was a significant predictor of residual melanoma at the time of surgery (Odds ratio 4.12, p=0.009). This finding coincided with the results in a backward elimination multivariable Firth logistic model.