Treatment of isolated testicular relapse in childhood acute lymphoblastic leukemia: an Italian multicenter study. Associazione Italiana Ematologia ed Oncologia Pediatrica.

Between May 1980 and April 1987, 49 children with acute lymphoblastic leukemia (ALL) in isolated testicular and first leukemia relapse (ITR) were enrolled in the Associazione Italiana Ematologia ed Oncologia Pediatrica (AIEOP) multicenter study REC80-ITR. According to the Rome Workshop criteria, 77% were at standard and 23% at high initial prognostic risk. In 33% of the cases, ITR occurred during first treatment. The REC80-ITR protocol consisted of an induction phase regimen of vincristine (VCR), cytarabine (ARA-C), methotrexate (MTX), and asparaginase (L-asp), and bilateral testicular irradiation, and CNS prophylaxis with intrathecal MTX and a maintenance phase with a multidrug rotating regimen. Total treatment duration was 30 months. The median time of observation after ITR was 51 months. The Kaplan-Meier estimates of survival and disease-free survival (DFS) at 4 years were 67.7% and 41%, respectively. Patients who had an ITR on therapy or within the first off-therapy year showed the poorest outcome. The DFS at 3 years was 20%, 47.6%, and 100%, respectively, for children who had an ITR on treatment (n = 16), within the first year of treatment withdrawal (n = 22), or later (n = 10) (P = .001). Patients with an asymptomatic occult testicular infiltrate at treatment discontinuation had a very unfavorable prognosis. Eighty-one percent of second relapses involved the bone marrow. In our experience, children presenting an early ITR (ie, within 6 months of treatment withdrawal) need a very aggressive treatment because of the high probability of an underlying systemic disease. On the other hand, patients with a late ITR seem to have a truly local recurrence and can apparently be cured by standard protocols, as shown in protocol REC80-ITR.