Acute lymphoblastic leukaemia (ALL) is a rare type of leukaemia in children under one year of age. However, it is of considerable interest due to its poor prognosis, especially in those with KMT2A gene rearrangements, which have been shown to arise during foetal development, before birth. In Europe, the incidence of ALL for this age group is estimated at 20 cases per million population.

While clinical research is working to develop new drugs and therapeutic strategies to treat this disease, understanding and avoiding the prenatal risk factors that lead to its onset may help to further reduce its incidence.

With this objective in mind, a research team from the Josep Carreras Institute, led by Dr. Rafael Marcos-Gragera as senior author, and researcher Arantza Sanvisens as first author, has reviewed all the available scientific evidence to identify the important risk factors for the onset of childhood ALL.

The research has been published in the scientific journal Cancers in collaboration with Dr. Clara Bueno, Dr. Oriol Calvete, Dr. Francesc Solé and the scientific co-direction of Dr. Marta Solans, a researcher at the University of Girona who collaborates with the Girona Cancer Registry. It provides a comprehensive overview of 33 observational studies analysing possible risk factors for Infant ALL and concludes that there are several well-established associations in the scientific literature, such as maternal exposure to pesticides and high birth weight.

It is considered that high birth weight, above 4kg, could be related to the development of ALL due to foetal growth factors, pointing to a possible organic cause yet to be discovered. This association has also been observed in other types of childhood leukaemia and is a field of research yet to be explored. On pesticide exposure, the authors conclude that exposed mothers have approximately twice the risk of their children developing ALL before the age of one year.

In addition to these well-established factors, the team identifies other interesting but weaker associations, such as high parental smoking, use of some medications (such as dipyrone) and maternal exposure to air pollution during pregnancy. These factors, however, require further research to determine their impact and, therefore, their risk.

The low incidence of ALL in infants precludes obtaining samples from adequate numbers of patients to develop more detailed statistical analyses, so there are not enough larger studies on the factors involved in its occurrence. The analysis requires large international research consortia, such as the Children's Oncology Group (COG) and the Childhood Leukaemia International Consortium (CLIC), which provided key data for the review.

This work not only reinforces the importance of identifying risk factors in the development of childhood leukaemia, but also highlights the need for increased research efforts to better understand the underlying causes of this disease in infants, a group that has so far been understudied in the field of paediatric oncology.

The study has received funding from the Spanish Government (ISCIII), the Generalitat de Catalunya (CERCA), the European Union (FEDER), the Josep Carreras International Foundation, the Spanish Association Against Cancer and the Unoentrecienmil Foundation. The drafting of this news item has been supported by generative AI tools.

Reference article: Sanvisens A, Bueno C, Calvete O, Solé F, Marcos-Gragera R, Solans M. Prenatal and Perinatal Factors Associated with Infant Acute Lymphoblastic Leukaemia: A Scoping Review. Cancers. 2025; 17(3):370. https://doi.org/10.3390/cancers17030370