Clinical course and prognostic factors of children with Burkitt’s lymphoma in a developing country: the experience of a single centre in Brazil more than one site of involvement; two had the involvement of abdomen and thorax and one had the involvement of the abdomen and paravertebral region. Of the patients with abdominal tumors, 18 underwent laparotomy, with total resection of tumor in 12 (26.7%) and partial resection in six (13.3%). Most patients had advanced disease (31 patients - 68.9%). Stage was reported for 44 patients: 13 were Stage II (28.9%), 28 Stage III (62.2%) and three Stage IV (6.7%). Serum LDH levels at diagnosis were available for 22 of the 45 patients with mean serum LDH being 676.5 IU/L (range: 112 to 7407 IU/L). Serum uric acid levels were available for 42 patients with a mean value of 5.4 mg/dL (range: 0.8 to 41.0 mg/dL). For 40 patients, the mean serum urea and creatinine levels were 23.5 mg/dL and 0.6 mg/dL, respectively. Serum potassium was available for 29 patients, with a mean value of 4.2 mEq/L (range: 3.0 to 5.2 mEq/L). Eleven patients (24.4%) received the LSA2L2 protocol and 30 patients (66.7%) the BFM-83 protocol. The other two patients were treated with other protocols and two patients died before the start of chemotherapy. Table 1 - Baseline clinical characteristics of 45 children with Burkitt’s lymphoma (n = 45) Characteristic Gender Male Female Clinical presentation (site) Abdomen Mediastinum Facial Other sites Clinical stage I-II III-IV Diagnostic procedure Cytopathology Biopsy and histological examination Immunophenotyping Nutritional status (WAZ)* < -1.28 > -1.28 Nutritional status (HAZ) † < -1.28 > -1.28 Age at diagnosis (years) Mean (range) n (%) 33 (73.3) 12 (26.6) 30 (66.7) 3 (6.7) 6 (13.3) 6 (13.3) 14 (31.1) 31 (68.9) 5 (11.1) 40 (88.9) 29 (64.4) 15 (33.3) 30 (66.6) 8 (20) 32 (80) 4.7 (11.5 m – 13.2 y ) * WAZ: Z score for weight in relation to age † HAZ: Z score for height in relation to age; there was no record of height at admission for 5 children Outcome Complete remission was observed in 38 patients (84.4%). During follow-up (median: 35 months; range: 1 to 60 months), 33 patients (73.3%) were alive at the first CR. Twelve children (26.7%) died, two of them soon after admission without receiving anticancer treatment. Eight died during the initial Rev Bras Hematol Hemoter. 2012;34(5):361-6 phase of chemotherapy and two after recurrence of the tumor in the CNS. The deaths were attributed to infection (n = 4), tumor lysis syndrome, refractory disease (n = 3) and “malignant hyperthermia” (n = 1). No information about the immediate cause of death was available for three patients. The estimated OS for all patients was 73% (Figure 1). The likelihood of OS for patients with localized disease and advanced disease was 92.3% and 67.7 %, respectively (p-value = 0.1 - Figure 2). Age, gender, LDH, potassium, urea, creatinine and nutritional indices were not significantly associated with patient outcome (Table 2). OS was 89.2% for patients with uric acid of less than 7.0 mg/dL at diagnosis and 35.7% for patients with uric acid levels of 7 mg/dL or higher (p-value < 0.001 - Figure 3). Figure 1 - Survival of 45 patients with Burkitt’s lymphoma. Small vertical lines on the curve represent patients alive at follow-up (Kaplan-Meier) Figure 2 - Survival of 45 patients with Burkitt’s lymphoma, stratified by localized versus advanced clinical stage. Small vertical lines on the curve represent patients alive at follow-up (Kaplan-Meier; log-rank test for comparison between survival curves) Figure 3 - Survival of 45 patients with Burkitt’s lymphoma, stratified by serum uric acid. Small vertical lines on the curve represent patients alive at follow-up (Kaplan-Meier; log-rank test for comparison between survival curves) 363