WASHINGTONNode-negative patients with intermediate-to-thick melanomas who underwent node staging by sentinel lymph node (SLN) biopsy had a significant survival advantage over those staged by elective lymph node dissection (ELND) or clinical examination, said Sophie Dessureault, MD, of the University of South Florida H. Lee Moffitt Cancer Center, Tampa. She spoke on behalf of the AJCC (American Joint Committee on Cancer) Melanoma Staging Committee.
Speaking at the 54th Annual Cancer Symposium of the Society of Surgical Oncology, Dr. Dessureault explained that earlier studies of SLN biopsy with lymphatic mapping in melanoma had found that it gives better information on regional node metastases. The current study investigated whether that advantage translates into improved survival for patients with negative nodes, while also saving them the morbidity of complete node dissection.
The AJCC melanoma staging database yielded 14,574 patients with negative nodes by SLN biopsy, ELND, or clinical examination. Retrospective analysis showed that, with a mean follow-up of 5 years, patients with melanomas thicker than 1 mm who had undergone SLN biopsy had a significant survival advantage over those staged by either ELND or clinical examination.
At 5 years, 90% of the SLN biopsy patients were alive, compared with 77% of ELND patients and 70% of clinical examination patients. SLN’s survival advantage persisted regardless of T stage or whether the tumor was ulcerated.
The SLN advantage may exist because the technique permits the pathologist to "focus on one node" rather than examine a larger number more superficially, Dr. Dessureault suggested. With ELND, pathologists "consistently miss microdisease," she said.
Using SLN biopsy for staging would produce "more uniform populations for arms in clinical trials," she added, and could also identify candidates for adjuvant therapy.