Randomized trials are needed to determine the optimal treatment approach for early stage follicular lymphoma (FL), according to researchers.
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A retrospective study showed similar outcomes among patients who received radiotherapy, immunochemotherapy, combined modality treatment (CMT), and watchful waiting (WW).
There were some differences in progression-free survival (PFS) according to treatment approach. However, there were no significant differences in overall survival (OS) between any of the active treatments or between patients who received active treatment and those managed with WW.
Joshua W. D. Tobin, MD, of Princess Alexandra Hospital in Brisbane, Queensland, Australia, and colleagues conducted this research and reported the results in Blood Advances.
The researchers analyzed 365 patients with newly diagnosed, stage I/II FL. The patients had a median age of 63 years and more than half were men. They were diagnosed between 2005 and 2017, and the median follow-up was 45 months.
Most patients (n = 280) received active treatment, but 85 were managed with WW. The WW patients were older and had more extranodal involvement.
Types of active treatment included radiotherapy alone (n = 171), immunochemotherapy alone (n = 63), and CMT (n = 46). Compared with the other groups, patients who received radiotherapy alone had less bulk, fewer nodal sites, and fewer B symptoms, and were more likely to have stage I disease. Patients who received CMT had fewer B symptoms and lower FLIPI scores compared with patients who received immunochemotherapy.
The immunochemotherapy regimens used were largely rituximab based. In all, 106 patients received rituximab (alone or in combination) for induction, and 49 received maintenance rituximab (37 in the immunochemotherapy group and 12 in the CMT group).
Results
Response rates were similar among the active treatment groups. The overall response rate was 95% in the radiotherapy group, 96% in the immunochemotherapy group, and 95% in the CMT group (P = .87).
There was a significant difference in PFS between the radiotherapy, immunochemotherapy, and CMT groups (P = .023), but there was no difference in OS between these groups (P = .38).
There was no significant difference in PFS between the immunochemotherapy and CMT groups (hazard ratio [HR], 1.78; P = .24), so the researchers combined these groups into a single group called “systemic therapy.” The patients treated with systemic therapy had PFS (HR, 1.32; P = .96) and OS (HR, 0.46; P = .21) similar to that of patients treated with radiotherapy alone.
Maintenance rituximab was associated with prolonged PFS among patients treated with systemic therapy (HR, 0.24; P = .017). However, there was no significant difference in OS between patients who received maintenance and those who did not (HR, 0.89; P = .90).
Relapse was less common among patients who received maintenance, and there were no cases of transformation in that group. Relapse occurred in 24.6% of the radiotherapy group, 18.3% of the systemic therapy group, and 4.1% of the group that received systemic therapy plus maintenance (P = .006). Transformation was less likely in the systemic therapy group (1.8%) than in the radiotherapy (6.4%) and WW (9.4%) groups (HR, 0.20; P = .034).
Overall, the active treatment group had better PFS than the WW group (HR, 0.52; P = .002), but there was no significant difference in OS between the groups (HR, 0.94; P = .90).
“Based on our comparable OS between WW and actively treated patients, WW could be considered as an initial management strategy in early stage FL,” Dr. Tobin and colleagues wrote. “However, long-term follow-up is required to determine if a survival benefit exists favoring active treatment.”
The researchers reported relationships with many pharmaceutical companies.
SOURCE: Tobin JWD et al. Blood Adv. 2019 Oct 8;3(19):2804-11.