Evaluating the role of informal caregivers in metastatic cancer patients treated with oral anticancer therapy: A prospective observational study.

11117 Background: The increasing use of oral anticancer agents (OAAs) in metastatic cancer has shifted treatment management from hospital to home, transferring responsibility for adherence and symptom monitoring to patients and informal caregivers. Evidence on caregiver burden and its impact on patient-reported outcomes in this setting remains limited. Methods: This prospective observational study evaluated patients with metastatic cancer receiving OAAs and their informal caregivers. At baseline and three months, patients completed the EORTC QLQ-C30, MMAS-8, TEMPS-A, and the G8 geriatric screening tool; caregivers completed the Zarit Burden Interview (ZBI), Caregiver Reaction Assessment (CRA), TEMPS-A, and an ad hoc caregiving questionnaire. Statistical analyses were performed using IBM SPSS Statistics (p < 0.05). Results: Sixty-eight patients (median age 67 years; 50% female) were enrolled; among patients aged >70 years, the G8 score indicated a predominance of non-frail patients (68.2%). 66.1% had a caregiver, most commonly a spouse (46.5%) or child (41.9%). Caregivers (mean age 56 years) were involved for >2 years in 76.7% of cases and attended outpatient visits in 69.8%. ZBI showed minimal/no burden in 60.5% and mild-to-moderate burden in 32.6%. CRA scores were highest for self-esteem (4.13±0.62), followed by schedule (3.31±1.36) and health (3.10±0.66). Patients with caregivers reported worse quality of life, physical, role, and emotional functioning, higher symptom burden (fatigue, pain, dyspnea, appetite loss, financial difficulties), and lower adherence compared with those without caregivers (all p<0.05). Caregiver presence was associated with cyclothymic, depressive, and anxious temperaments. Patients cared for by a child showed better role functioning, while spousal caregiving was associated with irritable temperament. At three months (n=22), patients showed significant improvements in adherence, quality of life, physical and role functioning, and symptom burden, suggesting early adaptation to oral therapy despite high baseline caregiving demands. Conclusions: Informal caregivers play a central role in OAA-treated metastatic cancer. Caregiver involvement appears to reflect greater patient vulnerability rather than a causal determinant of poorer outcomes, supporting the need for systematic caregiver assessment and targeted supportive interventions. Caregiver characteristics and associated patient outcomes. Variable Caregiver present No caregiver Patients, % 66.1 33.9 Relationship, % Spouse 46.5 / Child 41.9 – Care duration >2 yrs, % 76.7 – Presence at visits, % 69.8 – ZBI burden, % None/min 60.5; Mild–mod 32.6 – CRA self-esteem (mean±SD) 4.13±0.62 – Quality of life ↓ ↑ Physical functioning ↓ ↑ Symptom burden ↑ ↓ Therapy adherence ↓ ↑