Objective: Our study aims to review outcomes associated with primary pedal melanoma. We have preliminary data that pedal melanoma is associated with higher mortality and our current study investigates possible anatomic and patient related factors.
Methods: We performed a retrospective review of the Kaiser Permanente Northern California database and acquired demographic and clinicopathologic data for patients with primary pedal melanoma from 2007-2009 including Breslow depth, sentinel node status, presenting location on foot, ulceration, and stage. Univariate and multivariate analyses were conducted to examine association with survival.
Results: During the study period, 76 patients presented with melanocytic lesions of the following distribution: in situ 19 patients (25%), ≤ 1 mm 16 patients (21.1%), 1.01-2.0 mm 10 patients (13.2%), 2.01-4.0 mm patients (22.4%), >4 mm 14 patients (18.4%). Sentinel node biopsy was performed on 31 patients; positive sentinel node returned in 15 (48.4%) patients. 5-year survival for primary pedal invasive melanoma was found to be 68.4%. On univariate analysis, significant prognostic variables were found to include Breslow thickness, ulceration, sentinel node positivity, and presentation on toe. Multivariate analysis found ulceration and presentation on toe to remain independently prognostic. The 5-year survival for melanoma presenting on the toe was found to be 50%.
Conclusion: Primary pedal melanoma is associated with more advanced disease on presentation and overall poorer survival. Increased awareness and low threshold for biopsy may improve early diagnosis and outcomes.
