Achievement of event-free survival at 24 months (EFS24) is highly predictive of overall survival (OS) in patients with peripheral T-cell lymphomas (PTCLs), according to a new study.
PTCLs are a group of non-Hodgkin lymphomas with a generally aggressive clinical presentation. Previous research showed that EFS can be useful in stratifying patients with other lymphomas including diffuse large B-cell lymphoma and follicular lymphoma treated with immunochemotherapy, and researchers led by Andrew L. Feldman, MD, of the Mayo Clinic in Rochester, Minnesota, aimed to assess its use in PTCL as well.
The study included 775 patients with a median age of 64 years, included in initial cohorts from the United States and Sweden, and a replication cohort from Canada. Most of the patients were male (63%), and most had stage III or IV disease (74%). Results of the analysis were published online ahead of print in the Journal of Clinical Oncology.
In the initial cohorts, totaling 560 patients, 36% achieved EFS24 and 64% did not. Among those who progressed within the first 24 months, the median OS was 5.3 months, and the 5-year OS rate was 10%. In contrast, among the patients who did achieve EFS24 the median OS was not yet met, and the 5-year OS rate was 77%.
The investigators included the replication cohort due to the relative rarity of these malignancies and the heterogeneity seen between the two initial cohorts. The findings in the replication cohort were similar: 36% achieved EFS24 and 64% did not, and the median OS in those who did not achieve it was 4.5 months and the 5-year OS was 14% in those patients. In those who did achieve it, again the median OS was not met, and the 5-year OS was 81%.
When all the cohorts were combined, the median OS in those who progressed within the first 24 months was 4.9 months, and the 5-year OS rate was 11%. In those who did achieve EFS24, the median OS was not reached, and the 5-year OS was 78%. The best outcomes were seen in patients younger than 60 years of age.
“The data demonstrate that even in this group of patients with generally poor prognosis, those who remain event free 2 years after diagnosis have favorable long-term outcomes, with some patients potentially cured,” the authors wrote. “Conversely, events within 2 years are associated with early death in nearly all patients…. This endpoint may be useful for patient counseling and as an endpoint to assess novel biomarkers for risk stratification.”