Abstract
BACKGROUND: No previous review has assessed the extent and effect of industry interactions on medical oncologists and haematologists specifically. METHODS: A systematic review investigated interactions with the pharmaceutical industry and how these might affect the clinical practice, knowledge and beliefs of cancer physicians. MEDLINE, Embase, PsycINFO and Web of Science Core Collection databases were searched from inception to February 2021. RESULTS: Twenty-nine cross-sectional and two cohort studies met the inclusion criteria. These were classified into three categories of investigation: (1) extent of exposure to industry for cancer physicians as whole (n = 11); (2) financial ties among influential cancer physicians specifically (n = 11) and (3) associations between industry exposure and prescribing (n = 9). Cancer physicians frequently receive payments from or maintain financial ties with industry, at a prevalence of up to 63% in the United States (US) and 70.6% in Japan. Among influential clinicians, 86% of US and 78% of Japanese oncology guidelines authors receive payments. Payments were associated with either a neutral or negative influence on the quality of prescribing practice. Limited evidence suggests oncologists believe education by industry could lead to unconscious bias. CONCLUSIONS: There is substantial evidence of frequent relationships between cancer physicians and the pharmaceutical industry in a range of high-income countries. More research is needed on clinical implications for patients and better management of these relationships. REGISTRATION: PROSPERO identification number CRD42020143353.