How low is too low? Use of cluster analysis to define low levels of mercaptopurine metabolites

Abstract

This study provides an objective method for identifying patients at risk for treatment failure due to suboptimal 6-MP therapy; the clinical significance of this approach should be examined in future studies.

Correspondence Between Objective and Subjective Reports of Adherence Among Adolescents With Acute Lymphoblastic Leukemia

“…Using 6MP metabolites as a measure of adherence is a relatively new method, and results based on the classification system used in this study have only been reported in one previous study (Traore et al, 2006). In addition, the behavioral measures used in this study are newly developed self-report assessment tools.…”

“…Based on the findings from Traore et al (2006), participants were assigned to one of four clusters based on bioassay data of 6MP metabolites at each time point. Cluster 1 was characterized by a high TGN level and a low MMP level; Cluster 2 was characterized by a low TGN and a high MMP level; Cluster 4 was characterized by a low TGN and a very high MMP level.…”

“…A recent multi-site study used cluster analyses to group adolescents receiving treatment for ALL according to 6MP metabolite levels and to establish cutoff points to identify patients at risk for treatment failure due to suboptimal 6MP therapy (Traore et al, 2006). Analyses of the bioassay data from 48 patients resulted in four clusters.…”

The Challenges of Oral Agents as Antineoplastic Treatments

“…11 When biologic measures, such as urine or serum assays are used, specific ranges of blood or urine levels are expected to be associated with adherence to a medication regimen. 12,13 The operational definition of adherence is dependent upon which of these measures, or combination of these measures, is used to assess adherence.…”

Assessment and Measurement of Adherence to Oral Antineoplastic Agents

“…Direct serum or urine 55,57 measures were rare in adults, yet very common in pediatric oncology. 26,[63][64][65][66][67][68][69][70][71][72] However, these measures can only occur in the clinical setting when feasible and cost effective.…”