Why Does No One Want to Perform Lymph Node Dissection Anymore

In this issue of Annals of Surgical Oncology, Kingham et al. from Memorial Sloan-Kettering Cancer Center present their single-institution retrospective experience of melanoma patients who did not undergo completion lymph node dissection (CLND) for a tumor-positive sentinel lymph node (SLN). Of 313 patients who had a tumorpositive SLN, 271 underwent CLND and 42 did not. Of the 42 patients who did not undergo CLND, 5 did not do so because they were found to have stage IV disease on further workup, leaving 37 patients who should reasonably have considered CLND. The nodal recurrence rates were no different in the no-CLND group (7%) versus the CLND group (6%). Because the disease-free and disease-specific survival rates were similar between the groups, the authors question the value of CLND. We must recognize the limitations of this study. It is a small, retrospective review from a single institution. The groups are not well balanced in terms of clinicopathologic factors. Patients in the no-CLND group versus the CLND group were older (median age, 70 vs. 56 years, P \ .01), more often had lower-extremity melanomas (40% vs. 13%, P \ .01), and had a trend toward thicker (3.5 vs. 2.8 mm, P \ .06), more often ulcerated (62 vs. 44%, P = .09) melanomas. Why did the patients not undergo CLND in this study? In 33% of cases, it seems that the surgeon essentially talked the patient out of having a CLND. Although patient refusal was cited as the most common reason for failure to perform CLND (45%), it is likely that the surgeon’s opinion strongly influenced the patients’ decisions in these cases as well. The patients who chose to forego CLND did not do so for random reasons; selection bias is a major drawback of this study. In my experience, most patients choose CLND if recommended by their surgeon. So what does this study really tell us? I believe it tells us that the experienced melanoma surgeons at Memorial Sloan-Kettering Cancer Center were very good at selecting patients who were unlikely to have nodal recurrence and/or were very likely to develop distant metastatic disease, and thus were unlikely to benefit from CLND. It does not tell us that CLND is of no value. The authors cite population studies that indicate that only 50–69% of melanoma patients in the United States who have a tumor-positive SLN undergo CLND. So why are surgeons so reluctant to perform CLND these days? To address this question, we must consider the reasons for performing CLND. There are two goals: regional disease control and cure. The patients who undergo CLND for a tumor-positive SLN fall into three camps: (1) those who do not need CLND because they do not have, and never will have, additional nodal disease; (2) those who will not benefit from CLND because they are going to die of distant metastatic disease or because their disease will recur in the regional nodes, despite the best possible lymph node dissection; and (3) those who have nonsentinel node metastases for whom CLND will prevent regional nodal recurrence and, in some cases, result in cure. The third camp undoubtedly represents the smallest group. The article by Kingham et al. implies that the third camp does Society of Surgical Oncology 2009