The Use of Herbal Medicines Among Cancer Patients.

Background and objective The use of herbal medicines has been increasing among cancer patients, as a way to control cancer and treatment-related symptoms; however, many patients are reluctant to disclose this use to their medical practitioners. The fact that oncological treatments have a narrow therapeutic margin, associated with the lack of control and clinical evidence concerning these supplements, makes medication-herbal interactions a reality. These interactions could lead to increased toxicity or a decreased effectiveness of oncological treatment. In light of this, we aimed to assess the prevalence of herbal medicine use in a patient population at a Portuguese central hospital: Centro Hospitalar Lisboa Ocidental. Materials and methods Patients with breast, prostate, or colorectal cancer diagnoses between August 2022 and July 2023 and undergoing oncological treatment were included. Data were collected through a survey during their first appointment, as well as by consulting the patients' clinical files. An interaction evaluation was carried out to assess potential medication-herbal interactions. Finally, a statistical analysis was performed to identify predictive factors for the use of herbal medicines. Results Among the 65 patients included in the study, 52% were females, and the median age of the cohort was 65 years. Breast cancer was the most prevalent diagnosis and the majority of the patients were undergoing palliative treatment. We found that 46% of patients used herbal medicines regularly: to strengthen the immune system, detoxification of the body, and treat insomnia and constipation. A medication-herbal interaction was found in 37% of the cases, the most frequent being doxorubicin-vitamin C, through an antioxidant mechanism. The univariable analysis failed to show any predictive factors associated with the use of herbal medicines. Conclusions This study sheds light on herbal medicine use among cancer patients and the reality of medication-herbal interactions. There is an urgent need for further research and evidence-based medical protocols regarding herbal medicine use, especially in complex cases such as cancer patients, to provide better and safer care.