The goal of this observational cohort study is to compare the diagnostic accuracy and cost effectiveness of Risk of Malignancy Algorithm (ROMA) compared with CA125 in the diagnosis of ovarian cancer in patients attending their general practitioner (GP) with symptoms that sometimes might indicate ovarian cancer. The main questions it aims to answer are: • what is the accuracy of the ROMA algorithm which uses the blood tests CA125 and Human epididymis protein 4 (HE4) compared to CA125 in diagnosing ovarian cancer, particularly early-stage ovarian cancer, in women tested for suspected ovarian cancer from primary care? • What is the cost-effectiveness of ROMA versus CA125 testing in primary care to diagnose ovarian cancer? When a participant's GP orders a CA125 blood test, the blood will also be tested for HE4 and the ROMA algorithm calculated. The diagnostic accuracy of ROMA and CA125 will be compared to see if ROMA would be a better diagnostic test for ovarian cancer when used in the primary care setting.