Adherence to Oral Anticancer Agents Among Adults With Gastrointestinal Tract Cancer: A Scoping Review

Patients with gastrointestinal tract cancer reported suboptimal adherence to oral anticancer agents (OAAs), reducing their therapeutic benefit and increasing mortality risk. A scoping review can comprehensively map available evidence on adherence to OAAs and inform appropriate support to improve treatment outcomes.

The aim of this study was to comprehensively map studies on adherence to OAAs among adults with gastrointestinal tract cancer, including the adherence rate, nonadherence reasons, influential factors, management strategies, and theories that guide these studies.

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews Checklist and the 5-stage methodological framework of scoping review were followed. According to the 5 research questions, 7 databases were systematically searched for peer-reviewed original studies, and a narrative synthesis was performed.

Fifty-two studies were included. Adherence ranged from 16.7% to 100%, giving a median rate of 68% by self-report. Seven categories of nonadherence reasons were identified, with adverse effects, cancer progression, patient refusal, and forgetfulness being most frequently reported. Furthermore, more than 40 influential factors were identified. They are related to patient, disease condition, therapy, socioeconomic, and healthcare-system dimensions. Education and follow-up care were the main components of management strategies, but the effectiveness was inconsistent. Currently, only 3 of 52 studies adopted theoretical frameworks.

Adherence to OAAs among adults with gastrointestinal tract cancer is suboptimal. Future studies with rigorous designs and theoretical frameworks are needed to develop adherence-enhancing strategies and explain theoretical mechanisms.

Routine assessments and preventive actions are suggested to delay modifiable nonadherence.