The Association Between Anticholinergic Burden and Treatment-Related Complications in Older Adults with Cancer

BACKGROUND: Older adults constitute more than 50% of newly diagnosed cancer cases and polypharmacy is highly prevalent in this population. The Anticholinergic Burden (ACB) score quantifies the cumulative anticholinergic effects of all medications. Few studies link high ACB to adverse health outcomes in this population, and its effect on treatment outcomes remains largely unknown. OBJECTIVE: This study investigates the association between the ACB-score and treatment-related toxicity (grade ≥ 3), functional decline, and emergency room (ER) visits or hospitalization in older adults with cancer receiving chemotherapy and/or targeted therapy. METHOD: Data from the Triage of Elderly Needing Treatment study were used and patients aged ≥ 70 years were included before start of chemotherapy and/or targeted therapy. Medication use was used to calculate the ACB score; ACB ≥ 3 was defined as high. The primary outcome was the association between ACB score and grade ≥ 3 toxicity. Associations were analyzed using univariable and multivariable logistic regression. RESULTS: 434 patients were included with a median age of 75.4 years; 56% were male and 15% had a high ACB-score. Grade ≥ 3 toxicity occurred more frequently in the high ACB group (OR 2.04, p = 0.013). In the multivariable model, ACB score and frailty were associated with grade ≥ 3 toxicity (OR 1.99, p = 0.022 and OR 1.79, p = 0.007). CONCLUSIONS: High ACB is associated with poorer outcomes in older adults with cancer in addition to the known risk for toxicity of frailty.