Ovarian cancer. Coloured magnetic resonance imaging (MRI) scan of a frontal section through the abdomen of a 28-year-old woman, showing ovarian cancer (brown, upper centre). The cause of a malignant ovarian tumour is unknown, but taking fertility drugs and having a family history of the disease increases the risk. Symptoms of ovarian cancer include abdominal discomfort, vaginal bleeding and an increased frequency of urination. However, these usually develop only late in the disease, by which time the cancer may be large and has often spread to surrounding tissues. Treatment includes surgical removal of affected tissues, with radiotherapy and chemotherapy.