Alternatives and reduced need for sentinel lymph node biopsy (SLNB) staging for melanoma

Abstract

Sentinel lymph node biopsy (SLNB) has been introduced in the 1990s to identify patients who might benefit from completion lymph node dissection. Neither SLNB nor CLND improved survival, but SLNB staging did provide the best staging, above Breslow thickness and ulceration. The SLN status and SLN tumour burden were used in all trials until date looking at modern adjuvant systemic therapy with immune checkpoint inhibition (ICI) or targeted therapies (TT). Adjuvant ICI and TT are shifting towards stage II melanoma. The question is whether there is still role for SLNB in melanoma, in this day and age, and if so, how does the future look for SLNB staging? The SLN status and SLN tumour burden might be useful for a consultation to discuss the number needed to treat in a risk/benefit discussion. For stage IIB/C patients, it seems likely, however, that patients will forego a nuclear scan followed by the risk of surgical intervention and morbidity associated with SLNB if they opt to receive adjuvant therapy regardless of the SLNB result. For stage I/IIA, it is still required to detect high-risk patients who might benefit from adjuvant therapy. However, biomarkers are emerging, such as gene expression profilers (GEP), immunohistological signatures and liquid biopsies with ctDNA. There still is a role for SLNB staging in melanoma today, but we expect that the availability of therapeutic option independent of SLNB status as well as emergence of validated biomarkers to predict risk will reduce the need for SLNB staging in the upcoming decade to the point it will no longer be used.