2017, Vol. 35, No. 3
Surgical Treatment of Primary Melanoma: Where Do We Stand After MSLT-II?
In This Issue
From the Editors
Over time, surgical management of melanoma has evolved to reflect the adage attributed to Robert Browning that sometimes “less is more.” In the not so distant past, melanoma surgery was predicated on the belief that cancer consistently spreads by direct extension from the primary tumor to in-transit sites, then to the lymph nodes, then eventually to distant body sites and organs. For many decades, surgeons routinely employed radical procedures, including mutilating forequarter amputations, to interrupt this hypothesized inexorable progression. Over the years, based on improved understanding of the biology of metastasis and the results of numerous clinical trials, the extent of surgery has diminished. Radical en bloc resections gave way to 5 cm-wide local excisions and ultimately to 1-2 cm margins. Similarly, elective lymph node dissections gave way to sentinel lymph node biopsy (SLNB), pioneered by Donald Morton, with completion node dissections (CLND) reserved for those with positive sentinel nodes. Both the extent of local excision and the performance of SLNB became tailored to the primary tumor’s prognostic factors.
The standard of care in the recent past relied on the assumption that SLNB followed by CLND confers a survival advantage for patients with microscopic lymph node metastases. However, from the inception of the SLNB technique, Morton and colleagues appreciated the need to formally test this assumption. To this end, they undertook two long-term studies, the Multicenter Selective Lymphadenectomy Trials I and II (MSLT-I and MSLT-II). MSLT-I focused on the ultimate benefits of SLNB, and MSLT-II on the same for CLND.
In this issue of The Melanoma Letter, Dr. Mark Faries, who participated in both trials and led MSLT-II, explores what those trials found, the latter published just this year. In a nutshell, while MSLT-I found that SLNB may indeed confer an overall survival advantage in a small subset of patients, MSLT-II’s “practice-changing” findings showed that immediately removing the rest of the nodes (CLND) after a positive SLNB confers no overall survival advantage compared with watching and waiting until the nodes become clinically detectable. Based on these findings, CLND after a positive SLNB could soon fade into memory, much like ELND and 5 cm margins. Meanwhile, Dr. Faries offers considerable food for thought about the significant benefits offered by SLNB and CLND other than overall survival — enough possibly to keep the controversies about these techniques alive a while longer.
Allan C. Halpern, MD • Editor-in-Chief
Ashfaq A. Marghoob, MD • Associate Editor