Comparing the Outcomes of CHOP Chemotherapy Alone with Rituximab Plus CHOP for Hong Kong Chinese Patients with Diffuse Large B-Cell lymphoma

Diffuse large B-cell lymphoma (DLBL) is the commonest type of lymphoma worldwide. The condition is the same in Hong Kong and it accounts for about 30–40% of lymphoma cases. CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) was used for treatment of DLBL for many years. Rituximab, a chimeric anti-CD20 monoclonal antibody was used for the treatment of DLBL for about 10 years. Previous studies have shown the better efficacy of rituximab plus CHOP over CHOP alone, including the remission rate, overall and event-free survival. No previous study compared the efficacy of rituximab plus CHOP with CHOP alone in Hong Kong Chinese.

We conducted a study to compare the outcomes of CHOP chemotherapy alone with rituximab plus CHOP in a local hospital in Hong Kong.

It was a retrospective study from January 1999 to December 2009. Hong Kong Chinese patients with newly diagnosed diffuse large B-cell lymphoma were recruited in the study. They were divided into two groups. One group of patients was given CHOP chemotherapy and the other group was given rituximab plus CHOP. The remission rate, overall survival and event-free survival were compared in the two groups.

62 patients were recruited in the study. Twenty-nine patients with median age of 55 (range 23–77) were given CHOP chemotherapy alone. Thirty-two patients with a median age of 53 (range 20–75) were given rituximab plus CHOP. The baseline characteristics were similar in both groups. There were 41% of male patients in each group. IPI (international prognostic index) score as well as the proportion of patients at stage III and IV disease were similar in both groups.

The complete remission rate was 38% in CHOP alone group and 78% in rituximab plus CHOP group (p=0.002, Fisher's exact test).

The 3-year overall survival rate was 47% in CHOP group and 74% in rituximab plus CHOP group (p=0.043). The 3-year event-free survival was also better in the rituximab plus CHOP group (p=0.026). 19 events (including relapse, progression and death) were observed in the CHOP alone group and 8 events were observed in the rituximab plus chemotherapy group.

The side effects profile was similar in both groups and the rate of infection is comparable in both arms.

This study has shown that the use of rituximab plus CHOP was better than CHOP alone in Hong Kong Chinese patients with newly diagnosed diffuse large B-cell lymphoma. The complete remission rate, overall survival and event-free survival were significantly higher in the rituximab plus chemotherapy group.

No relevant conflicts of interest to declare.