Hysterectomy and kidney cancer risk: A meta‐analysis

Recent cohort findings suggest that women who underwent a hysterectomy have an elevated relative risk of kidney cancer, although evidence from past studies has been inconsistent. We conducted a systematic review and meta‐analysis of published cohort and case–control studies to summarize the epidemiologic evidence investigating hysterectomy and kidney cancer. Studies published from 1950 through 2012 were identified through a search of PubMed and of references from relevant publications. Meta‐analyses were conducted using random‐effects models to estimate summary relative risks (SRRs) and 95% confidence intervals (CIs) for hysterectomy, age at hysterectomy (<45, 45+ years) and time since hysterectomy (<10, 10+ years). The SRR for hysterectomy and kidney cancer for all published studies (seven cohort, six case–control) was 1.29 (95% CI, 1.16–1.43), with no evidence of between‐study heterogeneity or publication bias. The summary effect was slightly weaker, although still significant, for cohorts (SRR, 1.26; 95% CI, 1.11–1.42) compared with case–control findings (1.37; 95% CI, 1.09–1.73) and was observed irrespective of age at hysterectomy, time since the procedure and model adjustment for body mass index, smoking status and hypertension. Women undergoing a hysterectomy have an approximate 30% increased relative risk of subsequent kidney cancer. Additional research is needed to elucidate the biological mechanisms underlying this association.