BACKGROUNDMolecular testing to inform treatment and clinical trial choices is now the standard of care for several types of cancer. However, no established guidelines exist for the type of information physicians should cover during discussions with the patient about the test or its results. The objectives of this study were to identify physician and patient preferences regarding information and who should communicate this information and how to inform guidelines for these conversations. METHODSPhysicians and patients who participated in discussions regarding molecular testing were asked to choose 8 topics of most relevance out of a list of 18. The McNemar test was used to determine their top preferences. Patients were asked to identify what information they wanted to receive and who should inform them, and physicians were asked to identify the best aid to communication. RESULTSSixty-six patients identified 12 preferred topics: the benefits of testing (88%), how testing determines treatment (88%), implications for family (71%), whether a test indicates the seriousness of disease (68%), purpose of the test (64%), incidental findings (56%), explanation of cancer genetics (53%), how the test is done (46%), limitations (44%), explanation of biomarker (42%), risks (42%), and uninformative results (38%). Physicians added cost (59%). Patients preferred receiving information about molecular testing from their nurse or physician (85%), and physicians preferred using a pamphlet (67%) to augment communication. CONCLUSIONSThe topics identified as important to discuss can inform future guidelines and can contribute to effective communication regarding molecular testing. Cancer 2017;123:1610-1616. (c) 2017 American Cancer Society. This study provides important information regarding the topics that cancer patients perceive as the most relevant in their discussions on molecular testing. The authors recommend that their 12 preferred topics be discussed.