Central nervous system imaging is needed during programmed death 1 (PD-1) inhibitor therapy to monitor incidence, patterns of progression, and outcomes of melanoma brain metastases, according to research presented at the 2017 ASCO Annual Meeting (June 2-6, 2017; Chicago, IL).
Metastases in the brain is a common occurrence for patients with metastatic melanoma. Currently available therapies are often unable to treat metastatic melanoma tumors in the brain. Limited data exists concerning the incidence, patterns of progression, and outcomes of patients with melanoma brain metastasis treated with PD-1 inhibitors, particularly in conjunction with central nervous system-focused therapy.
Gustavo Schvartsman, MD, MD Anderson Cancer Center (Houston, TX), and colleagues retrospectively reviewed the survival outcomes of patients with metastatic melanoma treated with PD-1 inhibitors at the cancer center from 2012 to 2016. Correlation between clinical variables, development of melanoma brain metastases and overall survival (OS) were assessed.
A total of 324 patients with metastatic melanoma were identified, including 77 patients (24%) who had melanoma brain metastases before initiating PD-1 therapy. Median follow-up after initiating therapy was 16.3 months.
Authors also noted that median OS for patients without melanoma brain metastases before initiating PD-1 therapy was 3.37 years, whereas median OS for patients with prior melanoma brain metastases was 2.85 years (P = .268).
Among the 64 patients without prior melanoma brain metastases who developed metastases after exposure to PD-1 therapy, 21 developed metastases during therapy or within 30 days of discontinuation. Among those 21 patients, 12 demonstrated central nervous system progression and 9 had both systemic and central nervous system progression.
Of the 77 patients with metastases prior to PD-1 therapy, 22 demonstrated central nervous system progression during therapy. Progression occurred systemically in 12 patients and both systemically and in the central nervous system in 19 patients. Twenty-four of these patients exhibited stable disease.
Researchers acknowledged a 26% incidence of melanoma brain metastases after PD-1 therapy exposure. They concluded that patients who develop melanoma brain metastases are at higher risk of death, despite advancements in systemic and local central nervous system therapy.
Researchers call for the use of central nervous system imaging to monitor disease during PD-1 therapy. Furthermore, systemic therapy approaches are still needed for this poor prognosis population, they wrote.—Zachary Bessette
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