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Your search keyword '"Eleni Domzaridou"' showing total 2 results
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2 results on '"Eleni Domzaridou"'

1. The Impact of Oral Antibiotics Prior to Cancer Diagnosis on Overall Patient Survival: Findings from an English Population-Based Cohort Study

Author

Eleni Domzaridou, Tjeerd Van Staa, Andrew G. Renehan, Natalie Cook, William Welfare, Darren M. Ashcroft, and Victoria Palin

Subjects
antibiotics, antimicrobial resistance, cancer therapy, CPRD, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Background: There is limited evidence in humans as to whether antibiotics impact the effectiveness of cancer treatments. Rodent studies have shown that disruption in gut microbiota due to antibiotics decreases cancer therapy effectiveness. We evaluated the associations between the antibiotic treatment of different time periods before cancer diagnoses and long-term mortality. Methods: Using the Clinical Practice Research Datalink GOLD, linked to the Cancer Registry’s and the Office for National Statistics’ mortality records, we delineated a study cohort that involved cancer patients who were prescribed antibiotics 0–3 months; 3–24 months; or more than 24 months before cancer diagnosis. Patients’ exposure to antibiotics was compared according to the recency of prescriptions and time-to-event (all-cause mortality) by applying Cox models. Results: 111,260 cancer patients from England were included in the analysis. Compared with antibiotic prescriptions that were issued in the past, patients who had been prescribed antibiotics shortly before cancer diagnosis presented an increased hazard ratio (HR) for mortality. For leukaemia, the HR in the Cancer Registry was 1.32 (95% CI 1.16–1.51), for lymphoma it was 1.22 (1.08–1.36), for melanoma it was 1.28 (1.10–1.49), and for myeloma it was 1.19 (1.04–1.36). Increased HRs were observed for cancer of the uterus, bladder, and breast and ovarian and colorectal cancer. Conclusions: Antibiotics that had been issued within the three months prior to cancer diagnosis may reduce the effectiveness of chemotherapy and immunotherapy. Judicious antibiotic prescribing is needed among cancer patients.

Published
2023
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2. Do Systemic Antibiotics Prior to Cancer Diagnosis Impact on All-Cause Mortality for Malignant Cancers? Findings from Two UK Population-Based Cohort Studies

Author

Eleni Domzaridou, Tjeerd van Staa, Andrew G Renehan, Darren M. Ashcroft, Natalie Cook, Victoria Palin, and William Welfare

Subjects
medicine.medical_specialty, Chemotherapy, medicine.drug_class, business.industry, Proportional hazards model, medicine.medical_treatment, Antibiotics, Hazard ratio, Cancer, medicine.disease, Internal medicine, medicine, Medical diagnosis, business, Kidney cancer, Cohort study
Abstract

Background: In mice models of cancer and human tissues samples, disturbance of the gut microbiota can reduce the effectiveness of chemotherapy and immunotherapy. There is limited evidence in humans whether antibiotics impact on the effectiveness of cancer treatments. We evaluated the associations between antibiotic use before cancer diagnoses and long-term mortality. Methods: Primary care data from general practices contributing to the English Clinical Practice Research Datalink (CPRD) and Welsh Secure Anonymised Information Linkage (SAIL) linked to Cancer Registries (CR) and Office for National Statistics (ONS) mortality records were used. Two cohort studies involving cancer patients (15 types) exposed to antibiotics before cancer diagnosis were identified. Recent, previous and past antibiotic users were compared using Cox regression models. Findings: 129 990 cancer patients from the National Cancer Registration and Analysis Service (NCRAS) linked to CPRD and 131 330 from the Welsh Cancer Intelligence Surveillance Unit (WCISU) were included. In comparison with past antibiotic users, patients who used antibiotics in the recent past before their cancer diagnosis and were mainly treated with chemotherapy or immunotherapy presented increased hazards ratio (HR) for mortality consistently in both cohorts; for leukaemia, the HR in NCRAS was 1·40 (95% CI 1·22-1·60), for lymphoma 1·19 (95% CI 1·06-1·33), for melanoma 1·31 (95% CI 1·12-1·54), and for myeloma 1·19 (95% CI 1·04-1·36). HR for cancer of the uterus, breast, urinary, colorectal, and kidney cancer followed the same trend in both CRs. Sensitivity analyses based on general practice records suggested comparable results to those from CRs. Interpretation: This study supports the hypothesis that prior use of antibiotics may reduce the effectiveness of chemotherapy and immunotherapy, potentially through disruption to the gut microbiota. Although not providing definitive results, the biological plausibility of the findings does support the need for judicious use of antibiotics. Funding: Department of Health and NIHR. Declaration of Interest: We declare no competing interests. Ethical Approval: The protocol was approved by the Independent Scientific Advisory Committee for CPRD research (protocol number 18_198) and SAIL’s Information Governance Protocol Review Panel (protocol number 0855).

Published
2019

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