The modern techniques of lymphatic mapping and sentinel node (SN) biopsy (LM/SNB) were introduced for the management of cutaneous melanoma in 19921 and quickly found wide acceptance. They have also been applied to the management of squamous carcinoma of various sites, Merkel cell carcinoma, breast cancer, cancer of the upper and lower gastrointestinal tract, and gynecological malignant neoplasms.2 The presence or absence of metastatic melanoma in the SN provides optimal staging and is the most accurate available indicator of prognosis.3 There is less unanimity in regard to the therapeutic role of LM/SNB. Many clinicians (including me) believe that LM/SNB, with immediate completion lymph node dissection if the SN contains tumor, is a more effective way to treat patients with melanoma and early metastases to the lymph nodes than observation with delay of lymph node dissection until the tumor-containing nodes become clinically detectable. During such observation, the volume of nodal tumor and the number of tumor-containing lymph nodes increase and the American Joint Committee on Cancer stage becomes higher. Interim data from the first multicenter clinical trial of LM/SNB (MSLT-1) have been interpreted as supporting this view.4 Some commentators have expressed concerns about the design and statistical analysis of MSLT-1,5 but it is difficult to see how that trial could have been more effectively designed, given the extent of knowledge of the techniques at the inception of the trial. The true place of LM/SNB will likely not be determined until final analysis of MSLT-1 and its sister trial MSLT-2, in which the need for completion lymph node dissection in patients with a tumor-positive SN is being analyzed by randomizing such patients to immediate completion lymph node dissection or to observation using serial evaluation of the nodes by ultrasonography.
Cochran AJ. A Glimpse of Future Management of Melanoma. Arch Dermatol. 2009;145(10):1176-1177. doi:10.1001/archdermatol.2009.230