How not to miss...ovarian cancer

Oncologist Professor Sean Kehoe advises on how to spot ovarian cancer – and potential pitfalls

Ovarian cancer, when detected at an advanced stage, has a five-year survival rate of about 40%. But when it is detected with disease confined to the ovary, five-year survival is more than 90%. About 75% of women present with advanced disease.

Epidemiology

Ovarian cancer affects about 7,000 women each year in the UK, with a lifetime risk of at about one in 70. The condition affects mostly postmenopausal women, though it can occur in younger patients, even in teenage years. Other risk factors include:

• strong family history
• BRCA1/2 carriers
• nulliparity
• Lynch type 2 hereditary cancer syndrome.

Protection is afforded by pregnancy and use of the oral contraceptive. The latter can have a protective effect lasting for decades, even with a relatively short duration of use.

Symptoms and signs
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A major confounding factor in diagnosing ovarian cancer is the type of symptoms associated with it. These are numerous in nature and many are associated with non-ovarian – and indeed non-malignant – conditions.

From recent research there is now a consensus as to the main symptoms in women with ovarian cancer, which include:

• abdominal distension/bloating
• loss of appetite/feeling of fullness
• urinary frequency.

Many of the symptoms are associated with advanced disease, and often of short duration – hence ovarian cancer been termed ‘the silent killer'. Research is aiming to define symptoms that may help diagnose the disease earlier.

Abdominal symptoms can be due to a large ovarian mass, or also with associated ascites. Both produced pressure symptoms – causing bloating, bladder pressure, urinary frequency and feeling of fullness.

Postmenopausal bleeding is normally associated with endometrial cancer but occurs in about 5% of women with ovarian cancer, though most have other symptoms as well.

DVT: all patients with cancer have increased risk of coagulopathies, and combined with the pressures associated with pelvic masses, DVT may occur as a presenting symptom.

Dyspnoea: pleural effusions are associated with advanced disease and can cause dyspnoea. Most commonly the patients will also have ascites and abdominal swelling.

Bowel obstruction is due to metastatic disease or pressure from an ovarian mass. This is not very common.

Dermatomyositis and neurological disturbances (paraneoplastic syndrome) can occur in many malignancies and are considered a systemic manifestation of a primary cancer. Neurological signs in ovarian cancer are often related to walking difficulties. Intracranial lesions are very rare but may occur. Symptoms usually resolve with treatment of the malignancy.

Weight loss is due to cancer-associated cachexia with loss of appetite and in ovarian cancer specifically – from the inability to tolerate food because of pressure from a mass/ascites on the stomach.

Differential diagnosis
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• Other malignancies, for example bowel or metastatic carcinoma, peritoneal carcinoma
• Benign ovarian masses
• Uterine fibroids
• Distended bladder
• Irritable bowel syndrome
• Diverticular disease
• Ascites due to other causes: cardiac or liver failure

First-line investigations

In women with suspected ovarian malignancy, pelvic ultrasound and serum cancer antigen 125 (CA125) are the first investigations to be carried out. In women under 40 germ cell tumours are more common and produce HCG and a-fetoprotein (AFP), and these tumour markers should also be tested for.

When there is uncertainty about the presence of a pelvic mass, an ultrasound first – followed by a CA125 – is reasonable.

After referral a risk of malignancy index will be calculated using the serum CA125 levels, scan score and menopausal status. Women with scores of 250 or more are deemed at high risk of advanced ovarian cancer, and referred to a specialist gynaecological cancer centre.

Second-line investigations

When scans cannot clarify the mass, an MRI or CT scan can be helpful. Both may identify disease spread beyond the ovaries, as can ultrasound, though a laparotomy is the agreed method of staging the disease.

Professor Sean Kehoe is lead consultant for the Oxford Gynaecological Cancer Centre, John Radcliffe Hospital, Oxford, and fellow of St Peter's College Oxford

Competing interests None declared

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