EFS at 24 months stratifies outcomes in peripheral T-cell lymphoma

EFS at 24 months was a useful endpoint for stratifying outcomes among patients with peripheral T-cell lymphoma, study data showed.

“We previously used landmark analyses based on event-free survival to evaluate clinically useful end points in other aggressively treated lymphomas and showed that EFS24 stratified subsequent OS in diffuse large B-cell lymphoma and immunochemotherapy-treated follicular lymphoma,” Andrew L. Feldman, MD, consultant in the division of hematopathology and department of laboratory medicine and pathology at the Mayo Clinic, and colleagues wrote. “On the basis of these findings, we sought to evaluate EFS at 24 months and OS in peripheral T-cell lymphoma referenced to the general background population.”

The researchers reviewed data from 755 patients newly diagnosed with peripheral T-cell lymphoma from 2000 to 2012 in the United States and Sweden (initial cohort) and Canada (replication cohort). All patients were treated with curative intent. Feldman and colleagues defined EFS as the time from diagnosis to disease progression after the patient received primary treatment, underwent retreatment, or died. Researchers compared OS rates of patients to those of the general population, matched by age, sex and country.

The patients’ median age was 64 years, and most (63%) were men. The United States and Sweden showed similar results, and researchers performed a combined analysis of patients from the two countries. More than half of patients progressed in the first 24 months (64%). These patients had a median OS of 4.9 months and a 5-year OS of 11%.

Among patients who achieved EFS at 24 months, median OS was not reached (5-year OS, 78%). However, nearly one fourth of patients who achieved EFS at 24 months relapsed within 5 years (23%). Younger patients who achieved EFS at 24 months demonstrated superior outcomes, with those aged 60 years or younger achieving a 5-year OS rate of 91%.

“The marked differences in OS [among] patients with peripheral T-cell lymphoma who did and did not achieve [EFS at 24 months] suggest that this end point may be useful for patient counseling and as an end point to assess novel biomarkers for risk stratification,” the researchers wrote. –by Andy Polhamus

Disclosures: Feldman reports a consulting or advisory role with Infinity Pharmaceuticals, and is the inventor of technology for which Mayo Clinic holds an unlicensed patent or has submitted a patent. Please see the full study for a list of all other authors’ relevant financial disclosures.