[Long-term observations of children with acute lymphoblastic leukemia and high leukocytosis treated according to modified "New York" protocols (1987-2003)]. / Wieloletnie obserwacje dziec z ostra bialaczka limfoblastyczna i wysoka liczba krwinek bialych leczonych wedlug zmodyfikowanych protokolow "Nowy Jork" (1987-2003).

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Due to new therapeutic schedules and cooperation between oncological centers it is curable in more than 80% of affected children. For the optimalization of the therapy there is necessary to assess the risk criteria that have influence on the treatment results in the certain groups of patients. Hyperleukocytosis and the age (less than 1 year and more than 10 years) are known as unfavorable risk factors. The study was designed to assess the long-term treatment results in children with ALL and the initial leukocytosis over 50 000/mm3 with the use of the modified "New York" protocols. We present the treatment results of 340 children with ALL treated in nine centers of Polish Pediatric Leukemia/Lymphoma Study Group (PPLLSG) according to three consecutive versions of modified "New York" protocol (group I, II, and III) between 1987 and 2003. Within the analyzed groups the first complete remission (I CR) was achieved in 91%, 95% and 96% of the patients, respectively. Relapses occurred in 37%, 21.5% and 26% of the patients and 3.7%, 1.8% and 5.7% of children died in the I CR due to complications, in the I, II and III therapeutic group, respectively. Obtained 5-and 10-year event-free survival (EFS) were 56% and 53.5% for the group I and 73% and 73% for the group II. Five-year EFS for the group III was 67%. The implementation of the New York protocol in 1987 and New York I in 1997 has improved the treatment results in children with ALL and initial leukocytosis over 50 000/mm3. Protocol New York II did not further improve the treatment results. Among analyzed parameters (age, gender, the initial leukocytosis, the blast cells immunophenotype) only age had the statistical significance. The implementation of modified "New York" protocols has improved the treatment results in children with ALL and initial leukocytosis over 50 000/mm3 compared to previous results.