How not to miss – ovarian cancer

Worst outcomes if missed

- Death – there is considerable stage-by-stage variation in survival from ovarian cancer. If diagnosed at an early stage when it is confined to the ovary, prognosis from ovarian cancer is good with five year survival of 92%. But if diagnosed at an advanced stage when the disease has spread beyond the ovaries and to the abdomen or other organs, the prognosis is poor with five year survival of 5-20%. Unfortunately, 60% of cases of ovarian cancer are diagnosed at a late stage (III or IV) and hence the five year survival from the disease is low at 47%. This makes ovarian cancer the most lethal of gynaecological cancers.

- Morbidity – 32% cases of ovarian cancer are diagnosed following an admission to A&E. This is because the symptoms of ovarian cancer can be hard to recognise and are easily confused with bowel conditions (see below). Those with a greater burden of disease by the time of diagnosis are more likely to require more extensive surgery to debulk their cancer, and may require bowel resection, colostomy formation or nephrostomies. The amount of tumour left behind after surgery has important prognostic relevance, those with any residual macroscopic disease having a significantly worse prognosis¹.

Epidemiology

There are 6,500 thousand cases of ovarian cancer diagnosed in the UK per year. One in 50 women will be affected by the disease during her lifetime. Women most at risk of ovarian cancer are those over the age of 50. A minority of women with the disease may have a family history of breast and ovarian cancer, but the vast majority of cases of ovarian cancer have no environmental or genetic associations although there is a link with obesity and nulliparity.

Symptoms and signs

Women with ovarian cancer may have only a few presenting symptoms which can be confused for bowel conditions or natural ageing. However, it is important to think of ovarian cancer in someone aged over 50 who has persistent abdominal or pelvic pain, progressive abdominal distension with increasing girth, early satiety or urinary symptoms (urge or dysuria). A useful acronym is to “think BIG” – abdominal Bloating, Indigestion or feeling full after eating, and difficulties Going to the toilet. In some patients, their only symptoms are fatigue and weight loss, so think of ovarian cancer in these patients too.

Differential diagnoses

The main discriminator from benign conditions is in the pattern of symptoms - they are usually of relatively recent onset (within the last 12 months), are persistent and are frequent – occurring up to or over 12 times per month.²

- Irritable bowel syndrome (IBS) can cause abdominal bloating and change to bowel habits but the bloating is intermittent and related to food, and not persistent as with ovarian cancer. Associated symptoms of dysuria and reflux are not usually seen with IBS.  

- Natural age-related changes – although patients may confuse the subtle symptoms of ovarian cancer with ageing, the persistence and severity of symptoms like abdominal distension warrant investigation.

Investigations

- Abdominal and pelvic examination should be performed in the GP surgery to look for the shifting dullness of ascites. Also check for a solid mass in the adnexae or arising from the pelvis. If present, the patient should be urgently referred to their nearest gynaecological oncology clinic.

- In those with suggestive symptoms refer for a transvaginal ultrasound scan and perform a CA125 blood test – the normal range is less than 35 IU/ml. Although NICE guidelines advise doing a CA125 first, most gynaecological oncologists would recommend measuring CA125 but referring patients for ultrasound scan regardless of the result.³ This is because the CA125 can be inaccurate means of diagnosis.

- Exclude non-gynaecological causes for women with a normal ultrasound and a normal CA125.

- For those with CA125 greater than 35 IU/ml but normal ultrasound consider other non-gynaecological causes of elevated CA125 (see fourth red herring in box below) and advise repeat ultrasound and CA125 assessment in 4-6 weeks if symptoms persist but no other causes have been identified.