I am currently studying and preparing to take my OCN certification exam after working on an oncology unit the past year. I am just wondering if anyone here knows, as I cannot find any information anywhere else, regarding what source the question writers use for various cancer screening recommendations (what populations get tested and how and how often ect). I am using Core Curriculum for Oncology Nursing 5th edition to study and in the Screening and Early Detection chapter they have tables with this info, but from 3 different sources for each and they're all pretty different guidelines. I just want to make sure I'm studying the right ones that I should know for the test and not try to memorize all three as that is time consuming and maddening Any input from OCN nurses would be great! Any other tips on passing the OCN exam are also welcome. Thank you!