2 Clinical need and practice
2.1 Tests and risk scores are used in secondary care to help determine if a person referred with suspected ovarian cancer is likely to have an ovarian malignancy. Results inform decisions about whether they should be referred to a specialist multidisciplinary team (MDT) for further assessment and treatment. Currently, serum biomarker CA125 and pelvic ultrasound scans are widely used in secondary care, as part of the risk of malignancy index 1 (RMI I) score, in deciding whether a referral to a specialist MDT is needed. However, not all ovarian malignancies show elevated CA125 levels (particularly early stage ovarian cancer). Also elevated levels of CA125 are not always indicative of ovarian cancer, because they may be raised from other causes, such as endometriosis, fibroids, pregnancy, pelvic inflammatory disease, liver disease or heart failure. Tests and risk scores included in this assessment (ADNEX, Overa [MIA2G], RMI I at thresholds other than 250, ROMA and Simple Rules) may be better able to distinguish between benign and malignant ovarian tumours, and increase the proportion of people with a correct referral from secondary care to a specialist MDT.
2.2 Increasing the proportion of people with ovarian cancer who get a correct referral to a specialist MDT is likely to improve patient outcomes. Also, improved testing could lead to more accurate recognition of people referred to secondary care with suspected ovarian cancer who do not have the condition. This could reduce inappropriate referrals to specialist care for further assessment and treatment, as well as the costs and anxiety that this can cause.
2.3 Ovarian cancer starts in cells in, or near, the ovaries. Primary ovarian tumours are classified based on the tissue that they develop from, with 3 main types: epithelial ovarian tumours, sex cord-stromal tumours of the ovary and germ cell tumours of the ovary. Each subtype of tumour can be benign, malignant or intermediate (borderline malignant). About 90% of primary ovarian cancers are malignant epithelial tumours. Non-epithelial ovarian cancers make up a higher proportion of ovarian cancer in people who are premenopausal.
2.4 Data from Cancer Research UK (ovarian cancer statistics) suggests:
There were about 7,400 new cases of ovarian cancer in the UK in 2014, accounting for 2% of all new cancer cases.
The incidence of ovarian cancer increases with age, with more than half of cases between 2012 and 2014 happening in people aged 65 years and over.
There were about 50 new cases in people under 19 years in this time period, about 600 new cases in people under 40 years and about 1,400 new cases in people under 50 years.
2.5 The NICE guideline on ovarian cancer includes recommendations on criteria and tests to use in primary care when deciding whether to refer someone to secondary care with suspected ovarian cancer. Recommendations from this guideline have also been incorporated in the NICE guideline on suspected cancer.
2.6 The NICE guideline on ovarian cancer also provides recommendations on diagnosing suspected ovarian cancer in secondary care. An ultrasound of the abdomen and pelvis is recommended as the first imaging test in secondary care for people with suspected ovarian cancer (if this has not already been done in primary care), as well as measuring serum CA125 (if not already done in primary care). The guideline recommends calculating an RMI I score, based on characteristics seen on ultrasound, CA125 serum levels and menopausal status (described in more detail in section 3). It states that people with an RMI I score of 250 or more should be referred to a specialist MDT.
2.7 For people under 40 years with suspected ovarian cancer, the NICE guideline on ovarian cancer recommends measuring the levels of alpha fetoprotein (AFP) and beta human chorionic gonadotrophin (beta‑hCG), as well as CA125, to identify non-epithelial ovarian cancer.
2.8 The NICE guideline on ovarian cancer also provides recommendations on further imaging to characterise the extent and spread of ovarian cancer, and also on getting a tissue sample to confirm a diagnosis of ovarian cancer. Histopathology is generally used as the reference standard for assessing the accuracy of tests to identify people who are likely to have ovarian cancer. As well as distinguishing between malignant and benign tumours, this testing can also determine the type of ovarian cancer present. If tissue samples are not taken, clinical follow-up may be needed to determine the presence, or absence, of ovarian cancer.