In a recent issue of the Journal of Pediatric Hematology/Oncology, Seki and colleagues reported on risk factors for weight gain during induction chemotherapy in 96 childhood acute lymphoblastic leukemia (ALL) patients. In a retrospective study of medical records, they found that non–high-risk treatment for childhood ALL and treatment start date before daily weight measurement were risk factors for weight gain during induction therapy. They concluded that daily body weight measurements might prevent weight gain during induction therapy and can result in maintaining a healthy weight after aLL treatment.
We agree that early weight management should be emphasized, but question the study’s conclusions because of its methodological weaknesses. The retrospective design could have introduced surveillance bias and confounding. During the second half of the study period (after 2005), more focus was put on weight management as daily body weight measurements were initiated in an attempt to control weight. Patients who experienced weight gain in the second half of the study (after 2005) may have been more closely monitored than patients in the first half of the study (before 2005). The closer surveillance could potentially have led to difference in management, for example, diet control and water retention. Reverse causation may have occurred: overall differences in weight management, not the daily weight measurements, caused a weight reduction. More details on how weight gain found during induction was handled in the 2 periods would have helped the reader interpret this study.2 In the future, an intervention study with weight monitoring procedures in addition to normal clinical practice of daily weight measurements would assist gaining insight into good management of weight reduction.