Zeynep Eroglu, Kristy K Broman, John F Thompson, Amanda Nijhuis, Tina J Hieken, Lisa Kottschade, Jeffrey M Farma, Meghan Hotz, Jeremiah Deneve, Martin Fleming, Edmund K Bartlett, Avinash Sharma, Lesly Dossett, Tasha Hughes, David E Gyorki, Jennifer Downs, Giorgos Karakousis, Yun Song, Ann Lee, Russell S Berman, Alexander van Akkooi, Emma Stahlie, Dale Han, John Vetto, Georgia Beasley, Norma E Farrow, Jane Yuet Ching Hui, Marc Moncrieff, Jenny Nobes, Kirsten Baecher, Matthew Perez, Michael Lowe, David W Ollila, Frances A Collichio, Roger Olofsson Bagge, Jan Mattsson, Hidde M Kroon, Harvey Chai, Jyri Teras, James Sun, Michael J Carr, Ankita Tandon, Nalan Akgul Babacan, Younchul Kim, Mahrukh Naqvi, Jonathan Zager, and Nikhil I Khushalani
Until recently, most patients with sentinel lymph node-positive (SLN+) melanoma underwent a completion lymph node dissection (CLND), as mandated in published trials of adjuvant systemic therapies. Following multicenter selective lymphadenectomy trial-II, most patients with SLN+ melanoma no longer undergo a CLND prior to adjuvant systemic therapy. A retrospective analysis of clinical outcomes in SLN+ melanoma patients treated with adjuvant systemic therapy after July 2017 was performed in 21 international cancer centers. Of 462 patients who received systemic adjuvant therapy, 326 patients received adjuvant anti-PD-1 without prior immediate (IM) CLND, while 60 underwent IM CLND. With median follow-up of 21 months, 24-month relapse-free survival (RFS) was 67% (95% CI 62% to 73%) in the 326 patients. When the patient subgroups who would have been eligible for the two adjuvant anti-PD-1 clinical trials mandating IM CLND were analyzed separately, 24-month RFS rates were 64%, very similar to the RFS rates from those studies. Of these no-CLND patients, those with SLN tumor deposit >1 mm, stage IIIC/D and ulcerated primary had worse RFS. Of the patients who relapsed on adjuvant anti-PD-1, those without IM CLND had a higher rate of relapse in the regional nodal basin than those with IM CLND (46% vs 11%). Therefore, 55% of patients who relapsed without prior CLND underwent surgery including therapeutic lymph node dissection (TLND), with 30% relapsing a second time; there was no difference in subsequent relapse between patients who received observation vs secondary adjuvant therapy. Despite the increased frequency of nodal relapses, adjuvant anti-PD-1 therapy may be as effective in SLN+ pts who forego IM CLND and salvage surgery with TLND at relapse may be a viable option for these patients.