Purpose: We performed a phase II clinical trial to assess the efficacy and toxicity of the addition of rituximab and conventional chemotherapy in primary gastric lymphoma (PGL).
Methods: Forty-two (42) patients with PGL, stage IE and IIE, and with low- or low-intermediate clinical risk were treated in a prospective longitudinal study with standard CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy and rituximab (375 mg/m2, intravenously) on day 1 of each cycle administered every 21 days, for 6 cycles. The endpoint was to assess improvement in outcome measured by prolongation in event-free survival (EFS) and overall survival (OS). Complete response was achieved in 40 cases (95%) (95% confidence interval [CI]: 88%-102%). Relapse was observed in 2 cases. Two (2) patients died secondary to tumor progression. Thus, actuarial 5-year EFS was 95% (95 % CI: 87%-104%) and OS was 95% (95% CI: 88%-101%), which was not statistically different to historic controls. Acute toxicity was minimal and well tolerated, 4 cases developed late toxicity, 2 cases of herpes zoster infection, and 2 cases with granulocytopenia; in 1 case, the patient continued with mild granulocytopenia 3 years after treatment.
Conclusions: The addition of rituximab to CHOP chemotherapy did not improve outcome in early-stage PGL.