Keitaro Tanaka1, Akiko Tamakoshi2, Yumi Sugawara3, Tetsuya Mizoue4, Manami Inoue5, Norie Sawada5, Keitaro Matsuo6, Hidemi Ito6, Mariko Naito7, Chisato Nagata8, Yuri Kitamura9, Atsuko Sadakane10, Shoichiro Tsugane5, Taichi Shimazu5. 1. Department of Preventive Medicine, Faculty of Medicine, Saga University, Saga, Japan. 2. Department of Public Health, Hokkaido University Graduate School of Medicine, Sapporo, Japan. 3. Division of Epidemiology, Department of Health Informatics and Public Health, Tohoku University School of Public Health, Graduate School of Medicine, Sendai, Japan. 4. Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan. 5. Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan. 6. Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, Nagoya, Japan. 7. Department of Oral Epidemiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan. 8. Department of Epidemiology and Preventive Medicine, Gifu University Graduate School of Medicine, Gifu, Japan. 9. Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan. 10. Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan.
Abstract
BACKGROUND: Coffee and green tea, two popular drinks in the Japanese, have recently drawn much attention as potential protective factors against the occurrence of liver cancer. METHODS: We systematically reviewed epidemiologic studies on coffee, green tea and liver cancer among Japanese populations. Original data were obtained by searching the MEDLINE (PubMed) and Ichushi databases, complemented with manual searches. The evaluation was performed in terms of the magnitude of association in each study and the strength of evidence ('convincing', 'probable', 'possible', or 'insufficient'), together with biological plausibility. RESULTS: We identified four cohort and four case-control studies on coffee and liver cancer and six cohort and one case-control studies on green tea and liver cancer. All cohort and case-control studies on coffee reported a weak to strong inverse association, with a summary relative risk (RR) for one cup increase being 0.72 (95% confidence interval [CI] 0.66-0.79). Conversely, all studies but two cohort studies on green tea reported no association, with a corresponding summary RR of 0.99 (95% CI 0.97-1.01, P = 0.37). CONCLUSION: Coffee drinking 'probably' decreases the risk of primary liver cancer among the Japanese population whereas the evidence on an association between green tea and liver cancer is 'insufficient' in this population.
BACKGROUND: Coffee and green tea, two popular drinks in the Japanese, have recently drawn much attention as potential protective factors against the occurrence of liver cancer. METHODS: We systematically reviewed epidemiologic studies on coffee, green tea and liver cancer among Japanese populations. Original data were obtained by searching the MEDLINE (PubMed) and Ichushi databases, complemented with manual searches. The evaluation was performed in terms of the magnitude of association in each study and the strength of evidence ('convincing', 'probable', 'possible', or 'insufficient'), together with biological plausibility. RESULTS: We identified four cohort and four case-control studies on coffee and liver cancer and six cohort and one case-control studies on green tea and liver cancer. All cohort and case-control studies on coffee reported a weak to strong inverse association, with a summary relative risk (RR) for one cup increase being 0.72 (95% confidence interval [CI] 0.66-0.79). Conversely, all studies but two cohort studies on green tea reported no association, with a corresponding summary RR of 0.99 (95% CI 0.97-1.01, P = 0.37). CONCLUSION: Coffee drinking 'probably' decreases the risk of primary liver cancer among the Japanese population whereas the evidence on an association between green tea and liver cancer is 'insufficient' in this population.
Authors: Adriana C Vidal; Cynthia A Moylan; Julius Wilder; Delores J Grant; Susan K Murphy; Cathrine Hoyo Journal: Front Oncol Date: 2022-08-22 Impact factor: 5.738