SALVAGE THERAPY AFTER POSTOPERATIVE CHEMOTHERAPY FOR PRIMARY BRAIN-TUMORS IN INFANTS AND VERY YOUNG-CHILDREN

BACKGROUND. A trend coward the use of prolonged postoperative chemothe rapy, with radiotherapy deferred until relapse, has emerged for very y oung children with malignant brain tumors. This study was undertaken t o determine the failure patterns among infants who receive such treatm ent and to evaluate their responses to first salvage therapy, particul arly radiotherapy, after postoperative chemotherapy. METHODS, A retros pective cohort was assembled, which comprised all children younger tha n 36 months with biopsy-proven malignant brain tumors diagnosed during the years 1987-1993 at 3 pediatric oncology referral centers. Fifty-e ight children were treated with postoperative chemotherapy without irr adiation, 40 of whom experienced relapse of their malignancy. These pa tients' charts were reviewed for failure patterns. Thirty-five of thes e children received salvage therapy. Statistical and survival analysis with the Cox proportional hazards regression model was performed. RES ULTS. Among the 40 children who experienced relapse, 30 of 31 (97%) wi th solitary disease at initial diagnosis relapsed at, the primary site of disease. Thirty-seven of 39 infants (95%) developed relapse that i ncluded their primary site of disease. Sir;ty percent of relapses were asymptomatic and were detected by magnetic resonance imaging (MRI) su rveillance rather than by clinical examination. Two-year progression f ree survival (PFS) after relapse for infants who received salvage ther apy was 29% (standard error [SE] = 8%). For infants who received radio therapy alone, the 2-year PFS was 21% (SE = 9%). PFS did not differ ac cording to whether relapses were detected clinically or radiographical ly or treated by radiotherapy, chemotherapy, surgery, or multimodal th erapy. CONCLUSIONS. Relapse of brain tumors in infants after prolonged postoperative chemotherapy is largely a problem of local disease cont rol. Salvage is possible after prolonged postoperative chemotherapy, b ut it yields few instances of long term, progression free survival. No therapeutic modality is superior for salvage at relapse. A strategy o f reserving radiotherapy for the salvage of infants whose brain tumors relapse during postoperative chemotherapy demonstrated only limited e ffectiveness. Cancer 1998;83:566-74. (C) 1998 American Cancer Society.