AbstractObjectivesOral treatment (targeted or chemotherapy) for cancer is being increasingly used. While fatigue is a known side effect of intravenous chemotherapy, the rate of fatigue and the impact of fatigue on other patient-reported outcomes are not well described.MethodAt Massachusetts General Hospital Cancer Center, 180 adult patients prescribed oral targeted or chemotherapy for various malignancies enrolled in a randomized controlled trial of adherence and symptom management. Patients completed baseline self-reported measures of fatigue (Brief Fatigue Inventory; BFI), anxiety and depressive symptoms (Hospital Anxiety and Depression Scale; HADS), and quality of life, including subscales for physical, social, emotional, and functional well-being ([QOL] Functional Assessment of Cancer Therapy — General; FACT-G). We examined clinically relevant fatigue using a validated cut-off score for moderate-severe fatigue (BFI global fatigue ≥4) and tested the associations with anxiety symptoms, depressive symptoms, and QOL with independent samples t-tests.ResultsAt baseline, 45 of 180 participants (25.0%) reported moderate-severe fatigue. Fatigued patients experienced more anxiety symptoms (mean diff. 3.73, P < 0.001), more depressive symptoms (mean diff. 4.14, P < 0.001), and worse QOL on the total FACT-G score (mean diff. −19.58, P < 0.001) and all subscales of the FACT-G compared to patients without moderate-severe fatigue.Significance of resultsOne in four patients on oral treatment for cancer experienced clinically relevant fatigue that is associated with greater anxiety and depressive symptoms and worse QOL.