The treatment of childhood acute lymphoblastic leukemia in Guatemala: Biologic features, treatment hurdles, and results.

Background: The National Pediatric Oncology Unit (UNOP) is the only pediatric hemato-oncology center in Guatemala.

Methods: Patients ages 1 to 17 years with acute lymphoblastic leukemia (ALL) were treated according to modified ALL Intercontinental Berlin-Frankfurt-Münster (IC-BFM) 2002 protocol. Risk classification was based on age, white blood cell count, immunophenotype, genetics (when available), and early response to therapy.

Results: From July 2007 to June 2014, 787 patients were treated, including 160 who had standard-risk ALL, 450 who had intermediate-risk ALL, and 177 who had high-risk ALL. The induction death rate was 6.6%, and the remission rate was 92.9%. The rates of death and treatment abandonment during first complete remission were 4.8% and 2.5%, respectively. At a median observation time of 3.6 years, and with abandonment considered an event, the 5-year event-free survival and overall survival estimates ( ± standard error) were 56.2% ± 2.1% and 64.1% ± 2.1%, respectively, with a 5-year cumulative incidence of relapse of 28.9% ± 2.0%. Twenty-one of 281 patients (7.5%) investigated were positive for the ets variant 6/runt-related transcription factor 1 (ETV6/RUNX1) fusion.

Conclusions: A well organized center in a low-middle-income country can overcome the disadvantages of malnutrition and reduce abandonment. Outcomes remain suboptimal because of late diagnosis, early death, and a high relapse rate, which may have a partly genetic basis. Earlier diagnosis, better management of complications, and better knowledge of ALL will improve outcomes. Cancer 2017;123:436-448. © 2016 American Cancer Society.