||Treatment Outcomes for Diffuse Large B-Cell Lymphoma in the Rituximab Era: An Evaluation of 193 Patients
Haruka, IzumiKazuhiko, Natori
50 , 2015-09 , The Medical Society of Toho University
Background: Although rituximab, a chimeric anti-CD20 antibody, has been approved as a molecularly targeted drug in Japan, its information is still limited regarding the outcomes of combination chemotherapy including rituximab for treatment of diffuse large B-cell lymphoma (DLBCL). Methods: Combination chemotherapy including rituximab was administered to 193 of 243 patients who received histopathologic diagnoses of DLBCL at our department from January 2003 through December 2012. Results: Combination chemotherapy included the R-CHOP (rituximab, cyclophosphamide, adriamycin, vincristine, and prednisolone; n=161), R-CHO (rituximab, cyclophosphamide, adriamycin, and vincristine; n=20), R-HOP (rituximab, adriamycin, vincristine, and prednisolone; n=1) regimens, and other combination therapy (n=11). Therapeutic effect was evaluable in all 193 patients. Of the 182 patients treated with R-CHOP, R-CHO, or R-HOP, 140 (76.9%) had a complete response (CR) or unconfirmed CR (CRu), and 5 (2.7%) had a partial response (PR). Four of 11 patients treated with other combination chemotherapy regimens had a CR. Overall, 144 (74.6%) of 193 patients had a CR or CRu, and 5 had a PR; thus, the overall response (OR) rate was 77.2%. The 5-year disease-free survival rates were 72.9% for the 144 patients with CR or CRu, 90.5% for the International Prognostic Index (IPI) low-risk group, 75% in the low-intermediate-risk group, 83.0% in the high-intermediate-risk group, and 68.3% in the high-risk group. There were no significant differences among the 4 IPI groups. The 5-year survival rate was 72.8% overall, 85.2% in the low-risk group, 92.9% in the low-intermediate-risk group, 76.4% in the high-intermediate-risk group, and 49.1% in the high-risk group. The 5-year survival rate in the high-risk group was significantly lower than that in the other groups. Conclusions: These results show that treatment with combination chemotherapy including rituximab is superior to conventional CHOP or CHOP-like regimens. The validity of IPI, an established prognostic model for DLBCL, appears questionable for regimens with rituximab.