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P48. Duration of adjuvant immunotherapy in sentinel node positive melanoma: How important is completing a full year?

Thursday, March 5, 2026
3:14 PM - 3:21 PM MST
Location: 301D
Introduction: One year of adjuvant immunotherapy (IO) improves survival in patients with sentinel lymph node (SLN) positive melanoma. However, patients may prematurely discontinue treatment due to immune-related adverse events (irAEs), early disease recurrence, or other factors. The objective of this study was to determine whether a complete adjuvant IO course confers additional oncologic benefit for patients alive without recurrence a year after positive SLN biopsy.


Methods: This international retrospective cohort study compared duration of adjuvant IO (full course ≥1 year vs. partial course < 1 year) and recurrence-free survival among patients with SLN positive melanoma at 17 institutions July 2017-June 2022. Patients who underwent immediate completion axillary dissection or received other targeted therapy were excluded. To mitigate bias associated with early discontinuation of adjuvant IO due to recurrence, only patients who were alive with no recurrence one year after positive SLN biopsy (usual adjuvant IO window) were included. Analyses included Chi square tests, assessment of Kaplan-Meier curves, and Cox proportional hazards models adjusted for clinical variables including irAEs.


Results: Of 1,450 patients, 824 (56.8%) received adjuvant immunotherapy. Of these, 164 (20.0%) recurred and another 54 (6.6%) were lost to follow up and/or died in the year after SLN biopsy. Among the remaining 606 patients, 312 (51.5%) received a full IO course and 294 (48.5%) received a partial IO course (median partial duration 9 months (Interquartile Range [IQR] 5-11)). The two groups were well-matched for AJCC T and N stage. In a median clinical follow-up of 2.7 years (IQR 1.6-4.2) after the adjuvant window, there were 201 (33.2%) recurrences with no difference for full (31.7%) vs. partial IO (34.7%) (p=0.4). Kaplan-Meier curves (Figure) demonstrated greater recurrence with partial IO than full IO in the first two years after the adjuvant window which converged thereafter. In adjusted models, relative to full IO, partial IO was associated with increased risk of recurrence within one (HR=2.3, 95% CI 1.3-4.1) and two years (HR=1.7, 95% CI 1.1-2.4) after the adjuvant window. This difference was attenuated over the entire follow-up period (HR 1.2, 95% CI 0.9-1.7).


Conclusions: Among patients who were alive with no recurrence one year after a positive SLN biopsy for melanoma, a full IO course may protect against early recurrence within two years, but no difference was seen with longer follow-up. Future work should consider the impact of salvage strategies for recurrent disease on disease-specific survival.

Learning Objectives:

  • Participants should be able to describe the relationship between adjuvant immunotherapy duration and recurrence in the one- and two-year follow-up period and beyond.
  • Participants should better understand the impact of early cessation of immunotherapy on recurrence in SLN positive melanoma patients.