关键词: 恶性黑色素瘤, 前哨淋巴结活检, 区域淋巴结清扫, 预后

Abstract:

Background and purpose: For cutaneous and acral malignant melanoma, sentinel lymph node biopsy (SLNB) is an effective tool to evaluate the situation of regional lymph node metastasis and to determine the pathological stage. As an important part of the standard procedure for surgical diagnosis and treatment, SLNB has been recommended in major guidelines and already has a ten-year clinical application. Since the introduction of targeted therapy and immune therapy for malignant melanoma in 2017, the prognosis of patients has been significantly improved. This study aimed to collect the clinical data of Chinese malignant melanoma cases in recent five years so as to discover, in the era of new drug treatment, the significance of sentinel lymph node (SLN) status in clinical application and its influence on survival outcome. Methods: Data of 381 patients with histologically diagnosed malignant melanoma were retrospectively collected from 2017 to 2021 in Fudan University Shanghai Cancer Center. SLNB was performed with wide resection of the primary lesion for each case, and follow-ups of at least 6 months were taken afterwards. Lymphoscintigraphy or methylene blue dye was applied for identification of SLN. Results: A total of 381 patients were included. The mean Breslow thickness was 3.10 mm, among the 381 patients, 69.8% with acral lesion, 59.7% with ulceration, 34.6% with positive SLN, and the median relapse-free survival (RFS) was 17 months. Patient’s survival was significantly influenced by SLN status. Patients with more than 2 biopsied SLN had significantly better RFS in subgroups of N_1a stage and T₄ stage. There was no significant difference in RFS between patients who received complete lymph node dissection (CLND) and those who did no, and the latter even showed better RFS in subgroups of SLN biopsied number >2 and SLN micrometastasis diameter <1 mm. Conclusion: SLN status remained an important factor influencing the prognosis of melanoma cases with no clinical evidence of significant metastasis, and SLNB should be applied as a routine surgical procedure for malignant melanoma patients. While keeping the operation minimally invasive, the accuracy of SLN locating should be improved, and the sufficiency of biopsy should be ensured. Immediate CLND provides no improvement in the prognosis of cutaneous and acral melanoma patients with positive SLN status.

Key words: Malignant melanoma, Sentinel lymph node biopsy, Complete lymph node dissection, Prognosis