Effect of age at first use of oral contraceptives on breast cancer risk: An updated meta-analysis

Background: We evaluated the relationship between the age at first use of oral contraceptives (OC) and breast cancer (BC) risk. Methods: We searched PubMed, Embase, and related reviews published through June 28, 2018, and used summary relative risk (RR) and 95% confidence intervals (CIs) to evaluate the cancer risks, and fixed-effects dose–response meta-analysis to assess potential linear and non-linear dose–response relationships. Results: We included 10 studies, with 8585 BC cases among 686,305 participants. The pooled RR for BC was 1.24 (95% CI: 1.10–1.41), with moderate heterogeneities (I2 = 66.5%, P 
Source: Medicine - Category: Internal Medicine Tags: Research Article: Systematic Review and Meta-Analysis Source Type: research