Thompson, John F.

AbstractBackgroundIsolated limb infusion and perfusion (ILI/ILP) has been a mainstay treatment for unresectable melanoma in‐transit metastases (ITM), but increased use of immune checkpoint inhibitors (ICI) and intralesional therapy (talimogene laherparepvec [TVEC]) introduced several different management options. This study compares first‐line ILI/ILP, ICI, and TVEC.MethodsRetrospective review from 12 international institutions included patients treated from 1990 to 2022 with first‐line ILI/ILP, ICI, or TVEC for unresectable melanoma ITM.ResultsA total of 551 patients were treated, with ILI/ILP (n = 356), ICI (n = 125), and TVEC (n = 70) with median follow‐up of 5.5 years. Tumor burden was highest with ILI/ILP and lowest with TVEC (p = .002). Breslow thickness was lowest with TVEC (p = .007). TVEC was mostly used in stage IIIB disease versus IIIC for ILI/ILP and ICI (p = .01). Using ICI as the reference category, TVEC had the highest odds of a complete response (CR) (odds ratio, 1.96; p = .029) and a longer local progression‐free survival (PFS) (hazard ratio [HR], 0.40; p = .003). ILI/ILP had shorter local PFS (HR, 1.72; p = .012), PFS (HR, 1.79; p < .001), distant metastasis‐free survival (DMFS) (HR, 1.75; p = .014), overall survival (HR, 1.82; p = .009), and melanoma‐specific survival (HR, 2.29; p = .004). Stage IIIB disease had longer DMFS (HR, 0.24; p < .001) compared to IIIC/D.ConclusionsTVEC as first‐line therapy for unresectable melanoma ITM was associated with superior CR rates and local PFS. Notably, TVEC was used in patients with a lower Breslow thickness, disease stage, and tumor burden. Therefore, when compared to ILI/ILP and ICI, TVEC should be considered as first‐line therapy for unresectable stage IIIB melanoma ITM with minimal tumor burden and lower Breslow thickness.

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.

BackgroundFor patients with sentinel lymph node (SLN)‐positive cutaneous melanoma, the Second Multicenter Selective Lymphadenectomy trial demonstrated equivalent disease‐specific survival (DSS) with active surveillance using nodal ultrasound versus completion lymph node dissection (CLND). Adoption and outcomes of active surveillance in clinical practice and in adjuvant therapy recipients are unknown.MethodsIn a retrospective cohort of SLN‐positive adults treated at 21 institutions in Australia, Europe, and the United States from June 2017 to November 2019, the authors evaluated the impact of active surveillance and adjuvant therapy on all‐site recurrence‐free survival (RFS), isolated nodal RFS, distant metastasis‐free survival (DMFS), and DSS using Kaplan‐Meier curves and Cox proportional hazard models.ResultsAmong 6347 SLN biopsies, 1154 (18%) were positive and had initial negative distant staging. In total, 965 patients (84%) received active surveillance, 189 (16%) underwent CLND. Four hundred thirty‐nine patients received adjuvant therapy (surveillance, 38%; CLND, 39%), with the majority (83%) receiving anti–PD‐1 immunotherapy. After a median follow‐up of 11 months, 220 patients developed recurrent disease (surveillance, 19%; CLND, 22%), and 24 died of melanoma (surveillance, 2%; CLND, 4%). Sixty‐eight patients had an isolated nodal recurrence (surveillance, 6%; CLND, 4%). In patients who received adjuvant treatment without undergoing prior CLND, all isolated nodal recurrences were resectable. On risk‐adjusted multivariable analyses, CLND was associated with improved isolated nodal RFS (hazard ratio [HR], 0.36; 95% CI, 0.15‐0.88), but not all‐site RFS (HR, 0.68; 95% CI, 0.45‐1.02). Adjuvant therapy improved all‐site RFS (HR, 0.52; 95% CI, 0.47‐0.57). DSS and DMFS did not differ by nodal management or adjuvant treatment.ConclusionsActive surveillance has been adopted for most SLN‐positive patients. At initial assessment, real‐world outcomes align with randomized trial findings, including in adjuvant therapy recipients.Lay Summary For patients with melanoma of the skin and microscopic spread to lymph nodes, monitoring with ultrasound is an alternative to surgically removing the remaining lymph nodes. The authors studied adoption and real‐world outcomes of ultrasound monitoring in over 1000 patients treated at 21 centers worldwide, finding that most patients now have ultrasounds instead of surgery. Although slightly more patients have cancer return in the lymph nodes with this strategy, typically, it can be removed with delayed surgery. Compared with up‐front surgery, ultrasound monitoring results in the same overall risk of melanoma coming back at any location or of dying from melanoma.