title: Outcome of risk adapted therapy for relapsed/refractory acute lymphoblastic leukemia in children.
abstract: Results of second-line therapy for childhood acute lymphoblastic leukemia (ALL) remain suboptimal, particularly for high-risk groups identified using timing and site of relapse. We report results of prospectively collected data for pediatric patients with ALL who received risk adjusted second-line therapy. The 59 patients who failed first-line ALL therapy included 36 (61%) with bone marrow (BM), 13 (22.1%) with isolated extramedullary (EM) and 10 (16.9%) with BM + EM relapse. Some 51.8% patients were reinduced with high dose cytosine arabinoside (HDAraC)-based and 48.2% with standard four-drug regimens. In all, 38/56 (67.9%) achieved a complete remission (CR) with second-line therapy; the overall CR rate was 78.6% and was not associated with CR1 duration (p =0.8). Three-year overall survival (OS) was 45.3%, and was 61.4% for those achieving a CR. No risk group benefited from HSCT over chemotherapy. Patients with isolated EM relapse beyond 18 months of CR1 and BM relapse beyond 12 months off-therapy had an excellent outcome (OS 91.7%), identifying a particularly good-risk cohort. Patients not in this category continue with poor outcome even following hematopoietic stem cell transplant.
authors.affiliation: Department of Pediatric Hematology/Oncology, King Fahd National Center for Children's Cancer, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia. belgaumi@kfshrc.edu.sa
authors.forename: Asim F
authors.initials: AF
authors.lastname: Belgaumi
authors.forename: Amal
authors.initials: A
authors.lastname: Al-Seraihy
authors.forename: Khawar S
authors.initials: KS
authors.lastname: Siddiqui
authors.forename: Mouhab
authors.initials: M
authors.lastname: Ayas
authors.forename: Asem
authors.initials: A
authors.lastname: Bukhari
authors.forename: Abdulrahman
authors.initials: A
authors.lastname: Al-Musa
authors.forename: Ali
authors.initials: A
authors.lastname: Al-Ahmari
authors.forename: Hassan
authors.initials: H
authors.lastname: El-Solh
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D003561:Cytarabine / Q000008:administration & dosage; D019008:Drug Resistance, Neoplasm; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D015999:Multivariate Analysis; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000473:pathology / Q000628:therapy; D011446:Prospective Studies; D012008:Recurrence; D012074:Remission Induction; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D003561:Cytarabine