A primary care based, case control study has found that abdominal distension is the best predictor of ovarian cancer, with a positive predictive value (PPV) of 2.5%. Urinary frequency and abdominal pain were also significantly associated with ovarian cancer but had PPVs of <1%.

The medical records of more than 200 women registered with general practices in South-west England, aged over 40 years, with ovarian cancer were examined. The researchers looked for recorded symptoms in the months before diagnosis. Five age-matched controls were collected for each case.

Seven symptoms were found to have occurred more commonly among cases compared with controls; abdominal distension, urinary frequency, abdominal pain, anorexia, vaginal or rectal bleeding and bloating. The authors calculated PPVs for each symptom i.e. the chance that a woman with that symptom has ovarian cancer. All were <1% except for abdominal distension (2.5%). The high background rate of bloating, pain and urinary symptoms restricted the utility of these symptoms in predicting ovarian cancer.

An analysis excluding symptoms during the six months before diagnosis showed that: distension odds ratio (OR) 18 (95% CI 2.1 - 160, p=0.009), urinary frequency OR 3.1 (95% C1 1.3 - 7.3, p=0.009) and abdominal pain OR 2.6 (95% CI 1.5 - 4.6, p=0.001) were the best longer term predictors of ovarian cancer.

Ovarian cancer is typically diagnosed at an advanced stage when metastatic disease has already developed. Its overall five-year survival rate is just 35% however, those fortunate to be discovered with early stage disease have survival rates above 80%.

Ovarian cancer is not a silent killer. The background noise, however, is almost deafening, and therein lies the problem. My take home message from this important paper is to distinguish carefully when taking a history between bloating (a symptom that comes and goes) and distension (which is persistent) especially if progressive and associated with anorexia, pain or urinary symptoms. Diligent examination and pelvic ultrasound scanning in such women should follow.