Rituximab-CHOP Versus CHOP Alone in Patients with Diffuse Large B Cell Lymphoma.

Recently, the cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) regimen plus rituximab (R-CHOP) have been used widely to treat patients with newly diagnosed diffuse large B cell lymphoma (DLBCL) and it has also been reported to improve the outcome of DLBCL.

We represent a retrospective analysis of newly diagnosed DLBCL patients between the years of 2003–2005 to evaluate the impact of R-CHOP therapy on response rates.

Patients with DLBCL between 20–80 years of age (median: 46.0 and mean 56.2 ± 14.92) received 6 cycles of R-CHOP (n=28). For comparison, DLBCL patients between 15–76 years of age (median: 60.5 and mean 47.3 ± 16.6) who received 6 courses of CHOP therapy (n=30) were used as the control group. All patients received classical CHOP (cyclophosphamide 750 mg/m m², doxorubicin 50 mg/m², vincristine 1.4 mg/m m² on day 1 and prednisone 40 mg/m m² for 5 days) every 4 weeks. In R-CHOP group, rituximab 375 mg/m m² was administered one day before CHOP chemotherapy.

The median follow-up for R-CHOP and CHOP groups were 15.66 ± 5.90 (7–29) and 21.79 ± 9.20 (8–46) months, respectively. The International Prognostic Index (IPI) scores were not significantly different between these groups (median IPI of R-CHOP: 2.0 and mean IPI 2.01.27 ± 1.16 versus median IPI of CHOP: 1.0 and mean IPI 1.88 ± 1.26).

Complete response (CR) and complete undetermined response (CuR) rate for R-CHOP was 92% (26 of 28 patients) which was statistically significantly higher than CHOP (24 of 30 patients, 80%) (p=0.004). Partial response (PR) rates for R-CHOP and CHOP groups were 7% (2 of 28 patients) and 10% (3 of 30 patients), respectively. While there were no unresponsive patients in the R-CHOP group, refractory disease rate was 10% (3 of 30 patients) in the CHOP group. Relapse rates during the follow up period were 13% (4 of 30 patients) for CHOP and 4% (1 of 28 patients) for R-CHOP group (p<.0001). No long-term toxicity appeared to be associated with the addition of rituximab to the CHOP combination.

These results also confirmed the benefit of the addition of rituximab to standard CHOP chemotherapy in DLBCL even in young patients with low IPI scores.