Combining a questionnaire about woman's symptoms of abdominal bloating or discomfort with a blood test that detects cancer cells may improve the chances of detecting early stage ovarian cancer, a new study finds.

The blood test looks for the presence of CA 125, a protein that is a tumour marker which is found in greater concentration in ovarian cancer cells than in other cells of the body.

Researchers at the Fred Hutchinson Cancer Research Center in Seattle found that using a four-question questionnaire that asked women about their symptoms coupled with the CA 125 ovarian-cancer blood test detected early stage cancer in 60 per cent of women, and late stage cancer in 80 per cent.

A diagnosis of late-stage disease means survival rates are poor, in the 20 to 30 per cent range, according to the study.

Researchers also found that 11.8 per cent of women at a high risk for ovarian cancer who did not have the disease received a positive symptom index score, also known as a false positive.

"A composite marker such as this could serve as a first screen in a multistep screening program in which false positive findings are identified via transvaginal sonography before referral for surgery, leading to an adequate positive predictive value for the multistep program," reads the study.

"This research suggests that if a woman has one or more symptoms that are new for her, having begun within the past year, and if the symptoms happen nearly daily or at least 12 times a month, that may well be a signal to go in and discuss those symptoms with her doctor," said M. Robyn Andersen, lead author of the study, in a release.

Symptoms that may be indicative of ovarian cancer include abdominal or pelvic pain, a feeling of fullness after a small meal, having trouble eating and abdominal bloating.

The study included 254 healthy women at high risk of ovarian cancer and 75 women with the disease. It was published Monday in the journal Cancer.

The Canadian Cancer Society expects 2,500 women will be diagnosed with ovarian cancer in 2008 and 1,700 will die from it.