Imaging Intensity and Survival Outcomes in High-Risk Resected Melanoma Treated by Systemic Therapy at Recurrence

Abstract

Intensive imaging in melanoma remains controversial because its survival impact is unknown. We investigated the impact of imaging intensity on the rates of asymptomatic surveillance-detected recurrence (ASDR) and subsequent treatment outcomes in patients with access to immune checkpoint inhibitors (ICIs) and targeted therapy (TT). Patients with resected malignant melanoma undergoing imaging surveillance at a single center between 2006 and 2016 were identified. Surveillance and recurrence characteristics (imaging, symptom, treatment, and survival data) were retrospectively collected. Univariate (t test, Chi square test) and multivariate Cox regression analyses were conducted. Of 353 high-risk melanoma patients (stage IIB, 24%; IIC, 19%; IIIA, 27%; IIIB, 16%; IIIC, 14%), 71 (45%) had ASDR and 88 (55%) had symptomatic recurrence (SR). Shorter imaging intervals identified more ASDR (57%, 0-6months; 34%, 6-12months; 33%, > 12months; p = 0.03). ASDR had better prognostic factors than SR [fewer than three metastatic sites (43 vs. 21%, p = 0.003), normal lactate dehydrogenase (LDH; 53 vs. 38%, p = 0.09), brain metastases (11 vs. 40%, p < 0.001)] and received more systemic treatment (72 vs. 49%, p = 0.003; ICIs 55 vs. 31%, p = 0.002; TT 8 vs. 13%, p = 0.41). ASDR had better survival outcomes on ICI treatment (2-year OS, 56 vs. 31%, p < 0.001). Median OS from surveillance start was 39.6 vs. 22.8months (p < 0.001). ASDR was independently associated with survival (hazard ratio 0.47, 95% confidence interval 0.29-0.78, p = 0.003), adjusting for stage, sex, age, disease burden, LDH, era of recurrence, brain metastases, and ICI/TT treatment. These real-world data support further study on intensified imaging surveillance protocols for high-risk resected melanoma, as ASDR was associated with superior survival outcomes from ICI therapy.