Vaccination in patients with cancer: Gaps in coverage, barriers, and the role of clinician recommendations.

Cancer patients require a tailored vaccination strategy. This study aims to assess the vaccination status of cancer patients, evaluate disease incidence and severity in vaccinated individuals, identify reasons for noncompliance with guideline-recommended vaccines, and explore vaccine hesitancy. A cross-sectional survey, including 36 multiple-choice and 6 open-ended questions, was conducted in across Turkey. A total of 506 patients participated between September 1, 2024, and December 31, 2024. Among the participants, 59% (n = 302) were receiving active treatment. At the time of diagnosis, 90.5% did not have an ongoing vaccination program. Coronavirus Disease 2019 (COVID-19) (86.2%) and influenza (22.0%) were the most frequently received vaccines before treatment.The most common reason for not being vaccinated (except for COVID-19) was the absence of a medical recommendation. Higher education levels were associated with increased vaccination rates for hepatitis B, influenza, 13-valent pneumococcal conjugate vaccine (PCV13), and 23-valent pneumococcal polysaccharide vaccine (PPSV23) (p < .01). No significant relationship was found between disease stage and vaccination rates. The most frequently reported barrier to vaccination was the absence of a medical recommendation, highlighting the pivotal role of clinician engagement in improving vaccine uptake in this vulnerable population. Although international guidelines strongly recommend routine vaccination for patients with cancer, real-world data on vaccination practices, associated barriers, and health system - level implementation in middle-income countries are scarce. To address this evidence gap, this study provides real-world data on vaccination rates, determinants, and perceived barriers among cancer patients receiving care in a Turkish oncology setting.