Although relapses in patients with diffuse large B-cell lymphoma (DLBCL) typically occur within the first 2 years of diagnosis, the late relapse rate reached approximately 10% during the course of a recent study, with results published in the Journal of Clinical Oncology.
In this prospective analysis, 1324 patients had received immunochemotherapy for DLBCL, primarily involving rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone. DLBCL was diagnosed with an indolent lymphoma in 13% of patients, while 87% of patients were diagnosed with DLBCL alone.
Patients who achieved event-free survival at 24 months (EFS24) following diagnosis were evaluated for late relapses of either DLBCL or an indolent lymphoma occurring post-EFS24.
EFS24 was reached by 847 patients. These patients showed a cumulative incidence of late relapse of 6.9% (95% CI, 5.3%-8.9%) at 3 years after EFS24. This rate was 9.3% (95% CI, 6.7%-11.7%) at 5 years post-EFS24 and 10.3% (95% CI, 7.2%-13%) by 8 years post-EFS24.
Patients who experienced relapse with DLBCL showed poorer median survival following relapse (29.9 months) compared with patients who experienced relapse with an indolent lymphoma (not reached; P <.01).
At 5 years after EFS24, patients initially diagnosed with DLBCL and a concurrent indolent lymphoma showed a much greater incidence of late relapse of indolent lymphoma (7.4%) compared with patients diagnosed with DLBCL alone (2.1%; P <.01).
The incidence of late relapse of DLBCL at 5 years post-EFS24 did not depend on whether the initial diagnosis was of DLBCL alone or DLBCL with a concurrent indolent lymphoma (P =.46).
The risk of late relapse in DLBCL did not appear to vary between germinal center B-cell-like (GCB) and non-GCB subtypes (P =.71) for patients diagnosed with DLBCL alone. Relapse of an indolent lymphoma at 5 years after EFS24, however, occurred at a higher rate for patients with the GCB DLBCL subtype (3.9% vs 0.0%; P =.02) compared with patients with non-GCB DLBCL.
The study authors suggested that patients and their physicians remain aware of possible indicators of relapse. “It is critical to counsel patients that achieving EFS24 does not mean a cure, and the late-relapse risk is not trivial,” the authors stated.
- Wang Y, Farooq U, Link BK, et al. Late relapses in patients with diffuse large B-cell lymphoma treated with immunochemotherapy [published online June 6, 2019]. J Clin Oncol. doi:10.1200/JCO.19.00014