Checkpoint blockade and BRAF/MEK therapy in the therapeutic setting improved the overall survival after sentinel node biopsy: A retrospective study comparing patients with primary care between 1998‐2009 and 2010‐2017

Abstract

AbstractImmunotherapies using checkpoint blockade and BRAF/MEK therapies have improved overall survival (OS) in patients with unresectable melanoma metastases. In this retrospective study, we aimed to demonstrate the resulting increase in melanoma‐specific survival (MSS) and OS after the excision of primary melanomas (≥1 mm thick) and sentinel lymph node (SN) biopsy (SNB). Using Kaplan‐Meier estimates and Cox models, we compared two consecutive cohorts. Patients in cohort 1 (N = 518) underwent SNB between 1998 and 2009, and patients in cohort 2 (N = 460) between 2010 and 2017, when checkpoint blockade and BRAF/(MEK) inhibition became available for the treatment of unresectable relapses. The median follow‐up times were 120 and 73 months, respectively. While recurrence‐free and distant metastasis‐free survival rates remained very similar, MSS and OS increased in favor of cohort 2. The estimated 5‐year OS rate of SN‐positive patients increased by 14.3% (78.5% vs 64.2%, logrank test: P = .005). The MSS benefit was significant even with low SN tumor burden (metastasis diameter < 1 mm). On multivariate analyses, the risk‐reduction in favor of cohort 2 was significant in the total population and in the SN‐negative and SN‐positive subgroups. In SN‐positive patients, besides the availability of modern therapies, SN metastasis diameter and ulceration were independent factors of MSS and OS. Treatment of unresectable melanoma recurrences with modern drug therapies results in significantly higher survival rates in a population with SNB. The survival benefit measured from primary melanoma affects both the SN‐positive and SN‐negative subpopulations.