Staging in thick cutaneous malignant melanoma: A sequenced approach.

Abstract

Patients with thick cutaneous pT4 malignant melanoma are at high risk for metastatic disease, and optimal staging is poorly defined. This study examines the frequency and modality of pre-operative staging to provoke thought on optimal staging. A retrospective study was performed of patients with clinical T4N0 melanoma diagnosed between 2015-2017. The modality (sentinel lymph node biopsy and/or imaging), timing, and findings of staging investigations were assessed. One hundred thirty-six patients with pT4a or pT4b cutaneous melanoma and clinically negative regional lymph nodes were included. Forty patients underwent no staging. Thirty-six patients underwent pre-operative imaging, and of these, regional or distant disease was identified in seven patients (19%). Another 36 patients underwent upfront sentinel lymph node biopsy concurrently with wide local excision. A positive sentinel lymph node biopsy was found in eight (22%) of these patients, of which two had regional or distant metastatic disease on postoperative imaging. Of 16 who underwent a sentinel lymph node biopsy after negative pre-operative imaging, three had a positive sentinel lymph node biopsy. Staging is non-standardized and underutilized in patients with thick melanoma. With evolving systemic treatment options, a well-defined approach to staging, with consideration for pre-operative imaging in pT4 patients, is essential for high-risk patients.