Importance Informed consent is essential to ethical, rigorous research and is important to recruitment and retention in cancer trials.Objective To examine cancer clinical trial (CCT) participants’ perceptions of informed consent processes and variations in perceptions by cancer type.Design and Setting and Participants Cross-sectional survey from mixed-methods study at National Cancer Institute–designated Northeast comprehensive cancer center. Open-ended and forced-choice items addressed: (1) enrollment and informed consent experiences and (2) decision-making processes, including risk-benefit assessment. Eligibility: CCT participant with gastro-intestinal or genitourinary, hematologic-lymphatic (...) malignancies, lung cancer, and breast or gynecological cancer (N = 334).Main Outcome Measures Percentages satisfied with consent process and information provided; and assessing participation’s perceptions of risks/benefits. Multivariable logistic or ordinal regression examined differences by cancer type.Results Most patient-participants felt well informed by the consent process (more than 90% overall and by cancer type) and. most (87.4%) reported that the consent form provided all the information they wanted, although nearly half (44.8%) reported that they read the form somewhat carefully or less. More than half (57.9%) said that talking to research staff (i.e., the consent process) had a greater impact on participation decisions than reading the consent form (2.1%). A third (31.1%) were very sure of joining in research studies before the informed consent process (almost half of lung cancer patients did—47.1%). Most patients personally assessed the risks and benefits before consenting. However, trust in physicians played an important role in the decision to enroll in CCT.Conclusions and Relevance Cancer patients rely less on written features of the informed consent process than on information obtained from the research staff and their own physicians. Research should focus on information and communication strategies that support informed consent from referring physicians, researchers, and others to improve patient risk-benefit assessment and decision-making. (shrink)