This multicenter, cross-sectional observational study aims to evaluate the impact of financial toxicity on caregiver burden, quality of life, and emotional distress among hospitalized adult cancer patients. Participants will complete validated Turkish versions of the Zarit Caregiver Burden Scale, the EORTC QLQ-C30, and the Hospital Anxiety and Depression Scale (HADS). Financial toxicity will be assessed through indicators such as household income, treatment-related costs, and insurance coverage. Informed consent will be obtained from all participants. The study will not impose any financial burden on the participants or the hospital.

Data collection is planned between August 1, 2025 and January 15, 2026 at three tertiary centers: Etlik City Hospital, Gazi University Faculty of Medicine, and Kocaeli University Faculty of Medicine in Turkey. The findings are expected to contribute to the development of targeted support strategies for patients and caregivers in oncology settings.

This is a cross-sectional, multicenter observational study designed to assess the relationship between financial toxicity and caregiver burden, quality of life, and emotional well-being in hospitalized adult patients with cancer. The study population will include patients aged 18 years or older who are hospitalized in oncology wards and mentally capable of completing self-report questionnaires. Exclusion criteria include patients in intensive care units, those with impaired consciousness, severe psychiatric disorders, or those who are pregnant or lactating.

All participants will be asked to complete a battery of validated, Turkish-translated assessment tools covering multiple psychosocial domains:

The Comprehensive Score for Financial Toxicity (COST) will be used to assess perceived financial burden related to cancer care. The Turkish version consists of 11 items, each rated on a 5-point Likert scale. Total scores range from 0 to 44, with lower scores indicating greater financial toxicity. Financial toxicity will be further evaluated using self-reported data on household income, treatment-related out-of-pocket expenses, and insurance coverage.

The Zarit Caregiver Burden Scale (ZCBS) will be administered to evaluate caregiver burden, especially for informal caregivers such as family members. This 22-item instrument is rated on a 5-point Likert scale, generating a total score between 0 and 88. Higher scores reflect greater levels of burden. The Turkish version has demonstrated strong psychometric validity and reliability in oncology and geriatric care settings.

The Hospital Anxiety and Depression Scale (HADS) will be used to evaluate emotional well-being. It comprises 14 items divided into two subscales: anxiety and depression (each 7 items). Each subscale yields a score between 0 and 21; higher scores denote more severe emotional symptoms. The Turkish version has been validated for use in cancer patient populations.

The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) will be applied to assess quality of life across several domains. This 30-item questionnaire includes a global health status scale, five functional scales (physical, role, emotional, cognitive, and social functioning), and nine symptom scales. Each scale is transformed linearly to a 0-100 score, where higher functioning scores indicate better quality of life, and higher symptom scores reflect greater symptom burden. The Turkish version has been culturally and linguistically validated.

All participants will provide written informed consent prior to enrollment. No medical intervention will be applied, and the study will not impose any financial or logistical burden on the patients or the participating institutions. Participation is voluntary, and withdrawal from the study is permitted at any point without consequences. The study protocol has been reviewed and approved by the Scientific Research and Evaluation Board of Etlik City Hospital (BADEK). The study complies with the ethical principles outlined in the Declaration of Helsinki. Data will be anonymized, securely stored, and only used for academic purposes.

Data collection is scheduled to be conducted between August 1, 2025, and January 15, 2026, across three tertiary oncology centers in Turkey: Etlik City Hospital, Gazi University Faculty of Medicine, and Kocaeli University Faculty of Medicine. Data will be analyzed using descriptive statistics, group comparisons (e.g., independent samples t-test, ANOVA), correlation analyses, and multivariable regression modeling to explore the predictors of financial toxicity and associated psychosocial outcomes.

Inclusion Criteria:

• Age ≥ 18 years
• Histologically confirmed solid organ malignancy
• Currently receiving inpatient care in the medical oncology service
• Receiving active oncologic treatment and/or supportive care
• Fluent in Turkish (reading and speaking)
• Capable of understanding and answering the administered surveys
• Signed informed consent form

Exclusion Criteria:

• ICU admission at the time of enrollment
• ECOG Performance Status ≥3 or cognitive/clinical condition preventing completion of questionnaires
• Severe cognitive impairment or psychiatric condition interfering with survey participation
• Failure to provide informed consent

Hospitalized adult patients with a diagnosis of solid organ malignancy receiving active oncologic treatment or supportive care in the inpatient medical oncology clinic. All participants must be able to provide informed consent and complete validated Turkish questionnaires.

Individual participant data (IPD) will not be shared due to institutional policies and ethical considerations regarding patient confidentiality and data protection. Data use is restricted to the research team listed in the study protocol, and no external data sharing is planned at this stage.