Aspectos epidemiológicos, biotipologia e evolução do tratamento da leucemia linfocítica aguda na infância e adolescência no Rio Grande do Sul

Abstract

Acute lymphocytic leukemia (ALL) in childhood and adolescence is a neoplastic disease of varied lymphoid precursors. In Brazil, cooperative studies on the treatment of ALL started in 1980. According to these studies, the event free survival (EFS) was 50%, 58% and 70% in the protocols of 1980, 1982 and 1985, respectively. In this work, 1472 ALL patients were evaluated; 56.59% were male and 43.41% were female with ages that ranged between 0 and 20 years old (mean age of 7.4 years old). Data was collected from the records of patients with hematologic neoplasias in medical institutions that offered treatment for pediatric neoplasias in the period from 1980 to 2008. In this study, 487 patients (39.40%) were registered in the GBTLI protocol; 678 (54.85%) received treatment based on the BFM group regimen and 71 (5.75%) were treated according to other regimens. The EFS at five years of the patients on the GBTLI protocol was significantly higher than those who were not on this protocol (62.41% ± 2.43% and 53.86% ± 2.04%, respectively). In respect to the age range, the patients who were between 15 and 20 years old had an EFS of 37.98% ± 4.72% at five years, which is lower than the rate for 0 to 4-year-old and 5 to 9-year-old patients (62.78% ± 2.28% and 62.543± 2.84%, respectively). An overall survival of 63.73% ± 1.49% and EFS of 57.27% ± 1.57% were observed in the studied population. Epidemiologically, the incidence of ALL in B progenitors followed the pattern observed in developed countries with an absolute frequency peak in the age range of 2 to 4 year olds. The outcome was better for patients from urban areas compared to those from rural areas. EFS and overall survival in infant and Down syndrome patients were worse than the results obtained in developed countries.