Involved-field radiotherapy (IFRT) followed by cyclophosphamide, vincristine, prednisolone, and rituximab (R-CVP) significantly prolonged progression-free survival (PFS) for patients with follicular lymphoma (FL) compared with IFRT alone, according to a study published in the Journal of Clinical Oncology.
IFRT produces high levels of disease control in follicular lymphoma, but patients frequently experience relapse outside the irradiated regions. Previous studies have shown that combined modality therapy (CMT) with radiotherapy and sequential chemotherapy leads to positive outcomes in various lymphomas (eg, non-Hodgkin lymphoma), but its efficacy in follicular lymphoma is unknown.
For this study, researchers randomly assigned 150 patients with follicular lymphoma to IFRT alone or IFRT with chemotherapy (CVP, and after 2006, R-CVP). Chemotherapy was initiated 4 weeks post-IFRT in 3-week cycles for 6 cycles. Eligible patients had stage I to II low-grade disease, and the median age was 57 years old.
After a median follow-up of 9.6 years, patients who received CMT had significantly prolonged PFS compared to the IFRT alone group (P=.033). The estimated 10-year PFS rate was 59% among patients in the CMT group compared with 41% in the IFRT alone group. Patients who received CMT plus R-CVP had improved progression-free survival compared with contemporaneous patients treated with IFRT alone (P=.045).
Positive PFS outcome were associated with fewer involved regions and PET staging.
A total of 10 deaths occurred among patients treated with IFRT alone compared with 5 deaths among patients who received CMT, but overall survival did not differ significantly between the treatment groups.
The authors concluded that “we recommend treatment with IFRT followed by chemoimmunotherapy as a reasonable evidence-based choice for the standard of care. The combination of [radiotherapy] with more effective or less toxic systemic therapy regimens could potentially achieve superior results.”
MacManus M, Fisher R, Roos D, et al. Randomized trial of systemic therapy after involved-field radiotherapy in patients with early-stage follicular lymphoma: TROG 99.03[published online July 5, 2018]. J Clin Oncol. doi: 10.1200/JCO.2018.77.9892