Importance Although older patients are at increased risk of developing grade 3 or higher chemotherapy-related toxic effects, no studies, to our knowledge, have focused on the association between... Show moreImportance Although older patients are at increased risk of developing grade 3 or higher chemotherapy-related toxic effects, no studies, to our knowledge, have focused on the association between toxic effects and quality of life (QOL) and physical functioning.Objective To investigate the association between grade 3 or higher chemotherapy-related toxic effects and QOL and physical functioning over time in older patients.Design, Setting, and Participants In this prospective, multicenter cohort study, patients aged 70 years or older who were scheduled to receive chemotherapy with curative or palliative intent and a geriatric assessment were included. Patients were treated with chemotherapy between December 2015 and December 2021. Quality of life and physical functioning were analyzed at baseline and after 6 months and 12 months.Exposures Common Terminology Criteria for Adverse Events grade 3 or higher chemotherapy-related toxic effects.Main Outcomes and Measures The main outcome was a composite end point, defined as a decline in QOL and/or physical functioning or mortality at 6 months and 12 months after chemotherapy initiation. Associations between toxic effects and the composite end point were analyzed with multivariable logistic regression models.Results Of the 276 patients, the median age was 74 years (IQR, 72-77 years), 177 (64%) were male, 196 (71%) received chemotherapy with curative intent, and 157 (57%) had gastrointestinal cancers. Among the total patients, 145 (53%) had deficits in 2 or more of the 4 domains of the geriatric assessment and were classified as frail. Grade 3 or higher toxic effects were observed in 94 patients (65%) with frailty and 66 (50%) of those without frailty (P = .01). Decline in QOL and/or physical functioning or death was observed in 76% of patients with frailty and in 64% to 68% of those without frailty. Among patients with frailty, grade 3 or higher toxic effects were associated with the composite end point at 6 months (odds ratio [OR], 2.62; 95% CI, 1.14-6.05) but not at 12 months (OR, 1.09; 95% CI, 0.45-2.64) and were associated with mortality at 12 months (OR, 3.54; 95% CI, 1.50-8.33). Toxic effects were not associated with the composite end point in patients without frailty (6 months: OR, 0.76; 95% CI, 0.36-1.64; 12 months: OR, 1.06; 95% CI, 0.46-2.43).Conclusions and Relevance In this prospective cohort study of 276 patients aged 70 or older who were treated with chemotherapy, patients with frailty had more grade 3 or higher toxic effects than those without frailty, and the occurrence of toxic effects was associated with a decline in QOL and/or physical functioning or mortality after 1 year. Toxic effects were not associated with poor outcomes in patients without frailty. Pretreatment frailty screening and individualized treatment adaptions could prevent a treatment-related decline of remaining health. Show less
