Acute lymphoblastic leukemia: pathophysiology and current therapy.

Acute lymphoblastic leukemia (ALL) is seen in both children and adults, but its incidence peaks between 2 and 5 years and also increases in the older population. Although most children can be cured, the prognosis of adults with ALL remains poor. Recent identification of novel genetic alterations and sequence mutations has contributed to the elucidation of the pathogenesis of ALL. The World Health Organization classification was revised in 2016. ALL was included within the subgroup of myeloid neoplasms and acute leukemia. New provisional entities with recurrent abnormalities have been recognized and incorporated into the classification. Treatment of ALL involves some of the most complex chemotherapy combinations and treatment schedules used in oncology. Two main chemotherapy regimens are being used. The Berlin-Frankfurt-Münster framework consists of an induction regimen, consolidation regimen, reintensification regimen, and maintenance therapy and is mostly used in Europe for adult ALL trials. Another approach is to alternatively repeat two different intensive chemotherapy cycles, such as the hyper-CVAD regimen designed by investigators at the MD Anderson Cancer Center. Furthermore, the treatment of older patients with ALL is an unmet medical need. Novel targeted therapies, immunotherapies, and reduced-intensity SCT are promising approaches.