RT Journal Article SR Electronic T1 Short-term cancer risks associated with oral contraceptives are balanced by longer term benefits JF BMJ Evidence-Based Medicine JO BMJ EBM FD BMJ Publishing Group Ltd SP 115 OP 116 DO 10.1136/bmjebm-2017-110804 VO 23 IS 3 A1 Penelope M Webb A1 Susan J Jordan YR 2018 UL http://ebm.bmj.com/content/23/3/115.abstract AB