Background: Mainstreaming genetic-testing in cancer affected individuals, involves pre-test counselling, consent, and return of results by a member of the clinical cancer team. Pathogenic-variant (PV)-carriers are also referred to genetics services. This involves significant clinician time and resources. NHS guidelines recommend this for all ovarian, endometrial and colorectal cancer patients. Newer cost-efficient and scalable implementation strategies are needed given broadening access to cancer patients eligible for genetic-testing and available genetics workforce constraints. 

Primary Objective: To determine if a direct-to-patient (DTP) genetic-testing approach for ovarian, endometrial, and colorectal cancers is equivalent in terms of uptake of genetic-testing compared to mainstreaming by cancer clinicians. 

Hypothesis: Patients at ovarian, endometrial, or colorectal cancer diagnosis have equivalent uptake when offered genetic-testing through DTP compared to mainstreaming. 

Trial Design: Multicentre two-arm interventional equivalence randomised-controlled-trial evaluating a digitally enabled DTP (saliva-based, at home) genetic-testing approach (intervention-arm) compared to mainstreaming genetic-testing (control-arm). DTP-arm patients can access an app (Web/Android/Apple) based decision-aid; consent via the app, and call a helpline (optional) for additional support/counselling. Control-arm participants receive standard clinic-based mainstreaming genetic-testing. A qualitative sub-study (1:1 interviews) evaluates attitudes, experiences, and impact on emotional wellbeing of patients undergoing genetic-testing. A health-economic evaluation is being undertaken.  Inclusion/Exclusion Criteria: Inclusion-criteria: diagnosis of ovarian/endometrial/colorectal cancer fulfilling NHS genetic-testing criteria. Exclusion-criteria: prior genetic-testing or known familial PV in ovarian/endometrial/colorectal cancer susceptibility genes.  Primary-Endpoint: Uptake of genetic-testing (compared between arms).  Sample Size: 626-832, for 10% non-inferiority/superiority margin (difference considered clinically meaningful), for power=90%, and α=0.025.  Recruitment completion- end 2026; results published- 2028.  Trial Registration: ISRCTN-registry: 57402067