Adults with ALL, as well as the special category of adolescents and young adult (AYA) patients, are catching up with the new developments seen in children, but still their prognosis is much worse. children have a chance of long-term survival. Adults with ALL, as well as the special category of adolescents and Sulfo-NHS-LC-Biotin young adult (AYA) patients, are catching up with the new developments seen in children, but still their prognosis is much Sulfo-NHS-LC-Biotin worse. A plethora of factors are regarded as responsible for the differences in treatment response, such as age, ethnicity, disease biology, treatment regimens and toxicities, drug tolerance and resistance, minimal residual disease evaluation, hematopoietic stem cell transplantation timing and socio-economic factors. Sulfo-NHS-LC-Biotin Taking these factors into account, bringing pediatric-like protocols to adult patient management and incorporating new agents into frontline treatment could be the key to improve the survival rates in adults and AYA. strong class=”kwd-title” Keywords: acute lymphoblastic leukemia, prognosis, survival rates, adolescents and young adults, differences in treatment response, pediatric-like protocols, novel therapies 1. Introduction A crucial development in acute lymphoblastic leukemia (ALL) management occurred in 1947 when it was demonstrated that folic acid antagonists were efficient in inducing remission. The importance of acquiring complete remission (CR), the use of chemotherapeutic agents in combination, the prophylactic administration of intrathecal drugs, maintenance treatment during Sulfo-NHS-LC-Biotin remission and the improvement of supportive care are important factors that have contributed to a gradual increase in survival [1]. In the history of hematological malignancies management, there are few achievements as spectacular as the massive decline in the mortality from childhood leukemia. Between the 1960s to the 2000s, progress led to an increase of children surviving ALL from one in nine to approximately nine in ten. This improvement is attributed not as much to the discovery of new drugs, as it is to the Sulfo-NHS-LC-Biotin re-evaluation of the tools already in hand [2]. ALL can affect all individuals, from birth to the late stages of life, making it a very heterogenous disorder [3]. Over the last decades, patients with ALL have seen improved survival rates. However, as previously mentioned, this progress has mainly occurred in children and adolescents, with current 5 year event-free survival (EFS) rates varying from 76% to 86% [4,5] and getting up to 90% in some reports [6], whereas adults have much worse outcomes. ALL has a bimodal distribution regarding age, with peak incidences in children aged between 2 and 5 years and in adults older than 40 years [5]. In the pediatric population group, older children have poorer outcomes, and within adult populations, younger adults have better outcomes [7]. The adolescent and young adults (AYA) thus stand at the crossroads between these two age groups [8]. Survival rates in AYAs (generally defined as 16C39 years, but this definition is a subject of debate) are inferior and can decline by 50% between childhood and adulthood [9]. A recent analysis [10,11] indicated a better survival for adults in the past two decades, the most substantial improvement being seen in adolescents aged from 15 to 19 years, but still faring worse than children. The 5-year overall survival (OS) is 87% for children aged 0C15 years, as opposed to 63% for AYA aged 15C20 years and 44% for adults aged 20C29 years [12]. ALL is still a relatively infrequent disease in AYAs, so the data on this age group are limited and they are often analyzed either together with children or adults, depending on the pediatric or adult oncologists treating them [13]. The factors responsible for the different outcomes are various, including the disease heterogeneity, socio-economic factors, host factors, therapeutic protocols used and the experience of the health care professionals [14]. 2. Socio-Economic Factors ALL is the most common malignancy treated by pediatric hematologists [15]. Almost all children diagnosed with ALL are treated in specialized ICAM1 pediatric oncology centers, which have vast experience in this area, being involved in clinical trials, while adults are mostly treated by oncologists and probably have inferior access to clinical trials. Less than 2% of adolescents are enrolled in trials and this fact is associated with a poor outcome. They are treated by physicians and support teams with less experience with this disorder [12,15]. It is often invoked that young adults have poor compliance, are living independently, want to be emancipated, are concerned.