Improved treatment outcome of primary mediastinal large B-cell lymphoma after introduction of rituximab in Korean patients.

The addition of rituximab to cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) improved the outcome of patients with diffuse large B-cell lymphoma (DLBCL). However, the impact of rituximab (R-CHOP) is still not determined in primary mediastinal large B-cell lymphoma (PMBCL), a subtype of DLBCL, especially in Asian patients. Thus, we analyzed the treatment outcome of PMBCL patients (n = 21) treated with R-CHOP and compared it with the historical group treated with CHOP (n = 14). The rate of complete response for R-CHOP was higher than that of CHOP (17/21, 81.0% vs. 8/14, 57.2%), although the difference was not statistically significant (P = 0.151). The number of patients with disease progression or relapse was higher in the CHOP group (6/14, 42.9%) than the R-CHOP group (2/21, 9.5%). Thus, patients treated with R-CHOP had higher 2-year progression-free survival (79.0%) than those treated with CHOP (50.0%, P = 0.043). Although the 2-year overall survival of the R-CHOP was also superior to that of the CHOP group (82.7% vs. 57.1%), this survival benefit did not reach statistical significance (P = 0.081). In conclusion, our comparison suggests that R-CHOP may increase response and reduce relapse resulting in prolongation of progression-free survival of patients with PMBCL.