In 1999, the International Agency for Research on Cancer reported a potential association between oral contraceptive use and hepatocellular carcinoma , based on small-scale case-control studies. To further investigate this link, a large-scale analysis was conducted using data from 1,305,024 participants in the Million Women Study (MWS), 253,408 participants in the UK Biobank, and 23 observational studies involving 5,422 individuals with liver cancer. During follow-up, 2,765 participants in the MWS and 191 in the UK Biobank developed liver cancer.
No association was found between ever using oral contraceptives and liver cancer risk in either cohort (MWS: HR = 1.05; UK Biobank: HR = 1.08). Similarly, the meta-analysis of observational studies showed no overall association between oral contraceptive use and liver cancer (RR = 1.04). However, a slight increase in liver cancer risk was…
