Children and young adults with early-stage non-Hodgkin's lymphoma have an excellent prognosis, but treatment is prolonged and is associated with many side effects. We performed two studies to determine whether therapy could be simplified.

Between 1983 and 1991, we conducted two consecutive trials in children and young adults (age, <21 years) with early-stage non-Hodgkin's lymphoma. In the first trial, patients were treated for 9 weeks with induction chemotherapy consisting of vincristine, doxorubicin, cyclophosphamide, and prednisone, followed by 24 weeks of continuation chemotherapy with mercaptopurine and methotrexate. Half the patients were randomly assigned to receive involved-field irradiation. In the second trial, after the 9 weeks of induction chemotherapy, the patients were randomly assigned to receive 24 weeks of continuation chemotherapy or no further therapy.

A total of 340 patients were enrolled in the two trials, 12 of whom did not have complete remissions. One hundred thirteen patients received nine weeks of chemotherapy without radiotherapy, 131 received eight months of chemotherapy without radiotherapy, and 67 received eight months of chemotherapy with radiotherapy. At five years, the projected rates of continuous complete remission were 89, 86, and 88 percent for the three groups, respectively. At five years, event-free survival among the patients with early-stage lymphoblastic lymphoma was inferior to that among the patients with other subtypes of lymphoma (63 percent vs. 88 percent, P<0.001). Continuation therapy was effective only in patients with lymphoblastic lymphoma.

A nine-week chemotherapy regimen without irradiation of the primary sites of involvement is adequate therapy for most children and young adults with early-stage, nonlymphoblastic non-Hodgkin's lymphoma.