How should I approach the initial investigation of a patient presenting with abdominal pain and bloating that raises suspicion for ovarian cancer?

Initial investigations for a patient presenting with abdominal pain and bloating suspicious for ovarian cancer should start with a thorough abdominal and pelvic examination. If ascites or a pelvic/abdominal mass (not caused by known uterine fibroids) is found, the woman should be referred urgently to a gynaecological cancer service to be seen within 2 weeks for further investigation.

If the physical examination is normal, measure serum CA125 concentration. A CA125 level of 35 IU/mL or greater warrants an urgent ultrasound scan of the abdomen and pelvis.

If the ultrasound is suggestive of ovarian cancer, refer urgently to a gynaecological cancer service for further investigation.

If serum CA125 is normal (<35 IU/mL), or raised but with a normal ultrasound, consider other causes for symptoms or raised CA125. If no other cause is apparent, advise the woman to return if symptoms become more frequent or persistent.

These investigations are especially important in women aged 50 and over presenting with persistent or frequent symptoms such as abdominal distension (bloating), pelvic or abdominal pain, early satiety, or urinary urgency/frequency.