Abstract Background: Fasting has emerged as a potential modifier of cancer outcomes through effects on metabolism, treatment tolerance, and survivorship. For Muslim patients, Ramadan represents a month of religiously prescribed fasting, but clinical recommendations are limited for this population. clarify how patients approach Ramadan fasting and factors influencing safety, and given the lack of contemporary data, this study of 238 patients is one of the largest surveys to date to examine these practices in a Middle Eastern breast cancer cohort. We evaluated fasting practices, predictors, and patient-reported outcomes among breast cancer patients during Ramadan. Methodology: A cross-sectional survey was conducted at Al-Bairouni University Hospital, Syria’s national cancer center. All patients from the breast cancer unit diagnosed with breast cancer were included (N=238; 99.6% female; mean age 50.0 years). Measures included demographics, disease status, treatments, fasting behaviors, and factors influencing decisions. Predictors of fasting (none/partial/full) were evaluated with multivariable proportional-odds logistic regression. Results: Overall, patients' fasting patterns varied: 71.0% fasted for the entire month, 14.3% fasted only on certain days (defined as partial fasting), and 14.7% did not fast at all. Religious commitment was the primary motivator for fasting (85.8%). Despite their strong religious motivation, patients expressed a need for better medical guidance. Although 63.4% of patients desired clear medical guidance, only 43.8% of them consulted their oncologist about fasting. Among patients who fasted for the full month, self-reported adverse effects were generally mild, and no serious adverse events were reported. Fatigue was the most common mild symptom (32.5%), while 55.0% reported no health problems. Furthermore, 96.4% of the participants reported no negative impact on their treatment adherence, with some even reporting improved adherence. In adjusted models, older age was linked to lower odds of achieving full fasting (aOR 0.94 per year, 95% CI 0.91−0.97, p.001). Lower fasting odds were also predicted by metastatic disease (aOR 0.28; 95% CI 0.08−0.97, p=.046) and recurrent disease (aOR 0.17; 95% CI 0.04−0.91, p=.039). Conversely, patients who reported having equal trust in both physicians and religious leaders had threefold higher odds of fasting (aOR 3.0; 95% CI 1.5−5.8, p=.001). Conclusion: The findings suggest that most breast cancer patients can fast safely if they receive appropriate guidance; however, there is a clear need for evidence-based guidelines. Oncology teams should proactively address fasting in care plans through culturally tailored counseling to ensure effective patient care. Furthermore, collaboration with patients' religious leaders may enhance informed decision-making, a valuable and novel approach to improving patient support. Citation Format: A. Al-Bitar, A. Nasra, L. Alsaoub, G. Tannous, N. Rajjoub, A. Kouli, O. Johar, F. Kalam, M. Hafez. Fasting During Ramadan in Breast Cancer: Practices and Outcomes abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-13-09.
Al-Bitar et al. (Tue,) studied this question.