Twenty-four-month event-free survival (EFS) may be a surrogate for overall survival (OS) in patients with peripheral T-cell lymphoma, according to a recent study. Peripheral T-cell lymphomas are known to exhibit aggressive clinical behavior. Previous research has shown that EFS at 24 months can be utilized as a clinical endpoint in diffuse large B-cell lymphoma. However, EFS at 24 months has yet to be studied as a surrogate endpoint in peripheral T-cell lymphoma.
Matthew J Maurer, MS, Mayo Clinic (Rochester, MN), and colleagues conducted a study to evaluate whether EFS at 24 months can predict OS in peripheral T-cell lymphoma in large, multinational cohorts (n = 3). Researchers sampled 775 patients newly diagnosed with peripheral T-cell lymphoma from 2000 to 2012 who were treated with curative intent. EFS was defined as time from diagnosis to progression after primary treatment, retreatment, or death. Subsequent OS was assessed after achieving EFS at 24 months or from the time of progression if occurring within 24 months.
Results of the study were published in the Journal of Clinical Oncology (online October 26, 2017; doi:10.1200/JCO.2017.73.8195).
Among the total patient population, only 36% reached EFS at 24 months. The median OS was 4.9 months for the remaining 64% who demonstrated disease progression within 24 months, with an estimated 5-year OS of 11%.
In contrast, the median OS among those who reached EFS at 24 months was not reached; the estimated 5-year OS rate in this population was 78%. However, researchers acknowledged that relapse within 5 years of achieving EFS at 24 months occurred in 23% of patients, with a median OS of 10.3 months post-relapse.
Additionally, researchers noted that patients aged 60 years or younger were more likely to have a longer OS after reaching EFS at 24 months. Those with ALK-negative disease were more likely to reach EFS at 24 months, though their OS was shorter thereafter.
Authors of the study concluded that EFS at 24 months can be used to stratify subsequent outcomes in patients with peripheral T-cell lymphoma. “These marked differences in outcome suggest that [EFS at 24 months] has utility for patient counseling, study design, and risk stratification in [peripheral T-cell lymphoma],” they wrote.—Zachary Bessette