Salvage therapy after postoperative chemotherapy for primary brain tumors in infants and very young children

BACKGROUND. A trend coward the use of prolonged postoperative chemotherapy, with radiotherapy deferred until relapse, has emerged for very young children with malignant brain tumors. This study was undertaken to determine the failure patterns among infants who receive such treatment and to evaluate their responses to first salvage therapy, particularly radiotherapy, after postoperative chemotherapy. METHODS, A retrospective cohort was assembled, which comprised all children younger than 36 months with biopsy-proven malignant brain tumors diagnosed during the years 1987-1993 at 3 pediatric oncology referral centers. Fifty-eight children were treated with postoperative chemotherapy without irradiation, 40 of whom experienced relapse of their malignancy. These patients' charts were reviewed for failure patterns. Thirty-five of these children received salvage therapy. Statistical and survival analysis with the Cox proportional hazards regression model was performed. RESULTS. Among the 40 children who experienced relapse, 30 of 31 (97%) with solitary disease at initial diagnosis relapsed at, the primary site of disease. Thirty-seven of 39 infants (95%) developed relapse that included their primary site of disease. Sir;ty percent of relapses were asymptomatic and were detected by magnetic resonance imaging (MRI) surveillance rather than by clinical examination. Two-year progression free survival (PFS) after relapse for infants who received salvage therapy was 29% (standard error [SE] = 8%). For infants who received radiotherapy alone, the 2-year PFS was 21% (SE = 9%). PFS did not differ according to whether relapses were detected clinically or radiographically or treated by radiotherapy, chemotherapy, surgery, or multimodal therapy. CONCLUSIONS. Relapse of brain tumors in infants after prolonged postoperative chemotherapy is largely a problem of local disease control. Salvage is possible after prolonged postoperative chemotherapy, but it yields few instances of long term, progression free survival. No therapeutic modality is superior for salvage at relapse. A strategy of reserving radiotherapy for the salvage of infants whose brain tumors relapse during postoperative chemotherapy demonstrated only limited effectiveness. Cancer 1998;83:566-74. (C) 1998 American Cancer Society.