How to determine post-RCHOP therapy for risk-tailored adult patients with diffuse large B-cell lymphoma, addition of maintenance rituximab or observation: multicenter experience.

ABSTRACT

BACKGROUND: In international prognostic index (IPI) risk-tailored adult patients with diffuse large B-cell lymphoma (DLBCL), it is still unclear whether the addition of maintenance rituximab (MR) improves progression-free (PFS) and overall survival (OS), after RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) therapy. METHODS: In our study, 207 patients (age 21-59 years) received six 14-day cycles of RCHOP and gained overall response. After RCHOP, 98 patients were enrolled in the observation (OBS) arm. 109 patients continued to receive MR therapy. RESULTS: In IPI risk <2 profile, PFS at 5 years reached 72.9% (MR arm) versus 56% (OBS arm) (P = 0.033). In IPI risk ≥2 profile, PFS estimation at 5 years was 44.9% (MR arm) versus 33.5% (OBS arm) (P = 0.006). It is noteworthy that patients with IPI ≥2 who received MR achieved PFS similar to that for patients in the OBS arm with the IPI <2, 44.9% versus 56% (P = 0.97). In patients with an IPI <2, OS at 5 years was 83.2% (MR arm) versus 81.2% (OBS arm) (P = 0.708). In patients with an IPI ≥2, 5-year OS estimation was 44.6% (MR arm) versus 40.5% (OBS arm) (P = 0.067). Subgroup analysis of patients with an IPI ≥3 risk profile shows a survival benefit for patients receiving MR. OS at 5 years was 62% (MR arm) versus 49% (OBS arm), (P = 0.033). CONCLUSIONS: In conclusion, maintenance rituximab after RCHOP improves progression-free survival. In addition, overall survival is improved for patients with an IPI ≥3 risk profile receiving MR.