Methods: We harmonized data from 1,107,498 women who enrolled in 12 North American-based cohort studies (in the Liver Cancer Pooling Project, LCPP) and the UK Biobank between 1980-1998 and 2006-2010, respectively. Cox proportional hazards regression models were used to generate hazard ratios (HR) and 95% confidence internals (CI). Then, meta-analytic techniques were used to combine the estimates from LCPP (n=180 cases) and the UK Biobank (n=57 cases).
Results: Hysterectomy was associated with a doubling of ICC risk (HR=1.98,95%CI:1.27–3.09), compared to women aged 50-54 at natural menopause. Long-term oral contraceptive use (9+ years) was associated with a 62% increased ICC risk (HR=1.62,95%CI:1.03–2.55). There was no association between ICC risk and other exogenous hormone use or reproductive factors.
Conclusions: This study suggests that hysterectomy and long-term oral contraceptive use may be associated with an increased ICC risk.
|Number of pages||9|
|Journal||British Journal of Cancer|
|Early online date||07 May 2020|
|Publication status||Early online date - 07 May 2020|