After introducing a rituximab-containing chemoimmunotherapy (R-CHOP) for diffuse large B cell lymphoma (DLBCL), a partial response (PR) which is regarded as treatment failure is still observed. To investigate the prognostic factors for the DLBCL patients with a PR to R-CHOP, we retrospectively evaluated 758 newly diagnosed DLBCL patients. After R-CHOP, 88 (11.6%) achieved a PR. Three-year progression-free and overall survival rates measured from the date of PR achievement (PFS2 and OS2) were 57.4 and 67.8%, respectively. The secondary International Prognostic Index (IPI2) scores after R-CHOP were low (0-1) in 68.2% and high (2-3) in 31.8% of the patients. The Deauville scores from 18-fluorodeoxyglucose positron emission tomography after R-CHOP showed low (2-3) in 58.0% and high (4) in 42.0% of the patients. High IPI2 and high Deauville scores were associated with worse PFS2 (P < 0.001 and P = 0.009) and OS2 (P = 0.013 and P = 0.067). The high-risk group defined by the IPI2 and Deauville scores, whose scores were both high, showed significantly lower 3-year PFS2 (P < 0.001) and OS2 (P = 0.006) rates compared with those of the other groups. In multivariate analyses, the IPI score of ≥ 3 at diagnosis and bone marrow involvement at diagnosis were independent prognostic factors. In addition, high IPI2-Deauville score after R-CHOP was significantly associated with poor PFS2 (P = 0.009) and demonstrated a trend toward inferior OS2. In conclusion, DLBCL patients who partially responded to R-CHOP are still a heterogeneous group, for which IPI2 and Deauville scores should be evaluated for prediction of prognosis.
Keywords: Deauville scores; Diffuse large B cell lymphoma; FDG-PET; International Prognostic Index; Partial response.