CD5-positive diffuse large B-cell lymphoma: a retrospective study in 337 patients treated by chemotherapy with or without rituximab

BACKGROUND

CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) shows poor prognosis and frequent central nervous system (CNS) relapses under anthracycline-containing chemotherapy. The aim of this study was to determine the prognosis and CNS relapse incidence of CD5+ DLBCL in the rituximab era.

PATIENTS AND METHODS

We analyzed 337 patients with CD5+ DLBCL who received chemotherapy with (R-chemotherapy group; n = 184) or without (chemotherapy group; n = 153) rituximab.

RESULTS

No significant difference was found in clinical background comparisons between the two groups. In the R-chemotherapy group, 60% of the patients were older than 65 years at diagnosis. Both the complete response rate and overall survival (OS) were significantly better in the R-chemotherapy group (P = 0.0003 and P = 0.002, respectively). Multivariate analysis confirmed that chemotherapy without rituximab was associated with unfavorable OS. However, the probability of CNS relapse did not differ between the two groups (P = 0.89). The CNS relapse was strongly associated with short OS (P < 0.0001). In the R-chemotherapy group, 83% of patients who experienced CNS relapse had parenchymal disease.

CONCLUSIONS

Our results indicate that rituximab improves the OS of patients with CD5+ DLBCL but does not decrease the CNS relapse rate. More effective treatments with CNS prophylaxis are needed for CD5+ DLBCL patients.

Retrospective analysis of CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) treated with chemotherapy with or without rituximab

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Background: CD5+ DLBCL comprises 5–10% of DLBCL, and shows a high incidence of central nervous system (CNS) relapse. It has been included in the 4th WHO classification as an immunohistochemical subgroup. To clarify the prognosis and incidence of CNS relapse of CD5+ DLBCL in the rituximab-era, we conducted a multicenter retrospective study. Methods: We analyzed 313 patients (pts) with CD5+ DLBCL who received chemotherapy with (n=164) or without rituximab (n=149). The current series includes 107 out of 120 pts described in our previous study (Haematologica, 2008). Intravascular large B-cell lymphoma, primary CNS DLBCL, and secondary CD5+ DLBCL were excluded from the study population. Results: 313 pts showed the following clinical features: median age, 67 (range: 15–93); M:F=163:150; elevated serum LDH level, 71%; stage III/IV, 64%; IPI HI/H, 53%. No significant difference in clinical background such as the IPI and its five components, B symptom, male sex, and bone marrow involvement was found between pts who were treated with and without rituximab. Pts treated without rituximab received more dose-intensive chemotherapies (CHOP14, third-generation regimen, and high dose cytarabine-based regimen) than those treated with rituximab (24% vs. 7%, P<0.0001). The CR rate was higher in pts received rituximab than those without (81% vs. 65%; P=0.0014). The median follow-up was 28 months in pts who received rituximab (range: 7–77) and 68 months in those who did not (range: 6–187). Overall survival (OS) was significantly superior for pts with rituximab than for those without (2-yr OS: 68% vs. 54%, P=0.003). Multivariate analysis revealed that the use of rituximab was favorably associated with OS (HR=1.81, 95% CI: 1.26–2.58, P=0.001), but dose-intensive chemotherapies did not affect OS. However, the incidence of CNS relapse was not different between the two groups (2-yr CNS relapse rate: 11.9% vs. 11.4%, P=0.91). 16 of the 20 pts (80%) with CNS relapse in the rituximab group had brain parenchymal disease. Conclusions: Our data show that rituximab improves OS of pts with CD5+ DLBCL, but does not prevent CNS relapse. Future prospective studies to decrease CNS disease for CD5+ DLBCL are warranted.

No significant financial relationships to disclose.

Soluble interleukin-2 receptor retains prognostic value in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP (RCHOP) therapy

BACKGROUND

Soluble interleukin-2 receptor (SIL-2R) is known to be a prognostic parameter in patients with diffuse large B-cell lymphoma (DLBCL) receiving cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) therapy. However, its prognostic value has not been well known since the introduction of rituximab.

PATIENTS AND METHODS

We retrospectively evaluated the prognostic impact of SIL-2R in 228 DLBCL patients, comparing 141 rituximab-combined CHOP (RCHOP)-treated patients with 87 CHOP-treated patients as a historical control.

RESULTS

Patients with high serum SIL-2R showed significantly poorer event-free survival (EFS) and overall survival (OS) than patients with low SIL-2R in both the RCHOP group (2-year EFS, 66% versus 92%, P<0.001; OS, 82% versus 95%, P=0.005) and the CHOP group (2-year EFS, 40% versus 82%; OS, 61% versus 90%, both P<0.001). Multivariate analysis including the five parameters of International Prognostic Index (IPI) and two-categorized IPI revealed that SIL-2R was an independent prognostic factor for EFS and OS in the RCHOP group as well as in the CHOP group.

CONCLUSIONS

Our results demonstrate that SIL-2R retains its prognostic value in the rituximab era. The prognostic value of SIL-2R in DLBCL patients receiving rituximab-combined chemotherapy should be reassessed on a larger scale and by long-term follow-up.

CD5 expression is potentially predictive of poor outcome among biomarkers in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP therapy

BACKGROUND

Several biomarkers indicating poor prognosis have been reassessed in patients receiving rituximab combination chemotherapy for diffuse large B-cell lymphoma (DLBCL). However, few studies have investigated outcome in relation to a combination of these biomarkers. In addition, no large-scale studies have reassessed the outcome of patients with CD5-positive DLBCL treated with rituximab.

PATIENTS AND METHODS

We conducted a retrospective study and investigated the predictive value of three biomarkers -- BCL2, germinal center (GC) phenotype and CD5 -- in 121 DLBCL patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone.

RESULTS

CD5-positive patients showed significantly poorer event-free survival (EFS) and overall survival (OS) than CD5-negative patients (2-year EFS, 18% versus 73%, P < 0.001; 2-year OS, 45% versus 91%, P = 0.001). However, no significant difference in outcome according to BCL2 or GC phenotype was observed. Multivariate analysis revealed that CD5 expression was a significant prognostic factor for EFS [hazard ratio 14.2, 95% confidence interval (CI) 4.7-43.2] and OS (hazard ratio 20.3, 95% CI 3.6-114.4).

CONCLUSIONS

CD5 expression was the only significant prognostic factor among the biomarkers examined in this study. Further studies with larger numbers are warranted to confirm the prognostic significance of CD5 expression for patients with DLBCL receiving rituximab-containing chemotherapy.