Lower doses, better outcomes
In the question and answer session following the presentation, Jennifer Teichman, MD, MSc, a fellow in hematology at the University of Toronto who was not involved in the study asked why patients treated at adult centers would have higher relapse rates despite receiving higher doses of chemotherapy, noting that the poorer outcomes in those patients were not attributable to treatment-related mortality.
“I think one of the distinctions is that higher cumulative doses versus higher intensity of treatment over a shorter period of time are two different things, perhaps, and so giving lower cumulative doses but over a short period of time, and so giving higher intensity within that short period of time, may be what explains the higher success rate in pediatric trials,” Dr. Gupta said.
R. Michael Crump, MD, from the Princess Margaret Cancer Center, also in Toronto, asked whether the study results could have been influenced by differences between the pediatric center and adult center datasets in regard to pathology review, staging information, and International Prognostic Index.
Dr. Gupta acknowledged that, while the pediatric data were captured prospectively at each center by pediatric cancer registry staff and adult data were extracted retrospectively by trained chart reviewers, “the information that we were collecting was relatively basic – basic stage, basic histology, and that is a limitation.”
He also noted that clinicians reviewed the submitted retrospective data for completeness and had the ability to request chart extractors to return to a particular record for additional information or to correct potential errors.
The study was supported by the Canadian Institutes of Health Research, the C17 Council on Children’s Cancer & Blood Disorders, and the Pediatric Oncology Group of Ontario. Dr. Gupta, Dr. Teichman, and Dr. Crump all reported no relevant conflicts of interest.
SOURCE: Gupta S et al. ASH 2020, Abstract 708.