Treatment with cyclophosphamide, vincristine, and prednisolone (CVP) with or without rituximab (R-CVP) after involved field radiation therapy (IFRT) significantly improved progression-free survival, as compared with IFRT alone, among patients with stage 1-2 low-grade follicular lymphoma, according to a study presented at the 2016 American Society for Radiation Oncology (ASTRO) Annual Meeting.1
Although treatment with IFRT alone may be curative for patients with stage 1-2 low-grade follicular lymphoma, more than 50% of patients relapse, with most cases occurring predominantly outside radiotherapy fields. Researchers evaluated whether systemic therapy given after IFRT would improve progression-free survival in this patient population.
For the international trial, investigators enrolled 150 patients with stage 1-2, grade 1, 2, or 3a disease. Of those, 75% had stage 1, 52% were male, 48% were PET stage, and 8% had an extranodal site. Participants were randomly assigned 1:1 to receive IFRT alone or IFRT followed by 6 cycles of CVP or R-CVP.
Median follow-up was 9.6 years. Systemic therapy reduced the risk of progression or death by 43% as compared with IFRT alone (hazard ratio [HR], 0.57; 95% CI, 0.34-0.95; P = .033). There was, however, no significant difference in the 10-year overall survival rates between the 2 arms, suggesting that longer follow-up is needed.
Among those who specifically received CVP with rituximab, the risk of progression-free survival was 74% less than that of treatment with IFRT alone (HR, 0.26; 95% CI, 0.07-0.97; P = .045).
An extranodal site (P = .02), fewer involved nodal regions (P = .047), and PET staging (P = .056) were associated with improved disease control.
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Fewer patients in the systemic therapy arm had transformation to high-grade lymphoma, but significantly more grade 2 or worse adverse events were reported with systemic treatment.
- MacManus MP, Fisher R, Roos D, et al. Treatment with 6 cycles of CVP or R-CVP after involved field radiation therapy (IFRT) significantly improves progression-free survival compared to IFRT alone in stage I-II low grade follicular lymphoma: Results of an international randomized trial. Oral presentation at: 2016 American Society for Radiation Oncology (ASTRO) Annual Meeting; September 25-28, 2016; Boston, Massachusetts.