Scientists identify ovarian cancer biomarker

Ovarian cancer is known as the “silent killer” because it often remains hidden until a late and dangerous stage.

Each year about 7,000 UK women are diagnosed with ovarian cancer and 5,000 die from the disease but there remains no way of identifying the disease early when there are no obvious symptoms.

Discovering the new biomarker, an antibody forming part of the immune system, could pave the way to screening women at high risk of ovarian cancer or those with early-stage tumours, say researchers from the United States.

Lead scientist Professor Judith Luborsky, from Rush University in Chicago, said: “The finding is extremely important because at present medical tests are unable to detect ovarian cancer at its early stages, which is why death rates from this disease are so high.

“Our approach to discovering cancer biomarkers was unique in this study. Instead of investigating molecules specific to ovarian cancer alone, we asked what molecules women with a risk of ovarian cancer and those with ovarian cancer had in common.”

The strategy revealed a link between the mesothelin antibody, infertility, and ovarian cancer. A strong association between infertility and the disease was already known from previous studies.

Prof Luborsky’s team tested for mesothelin antibodies in the blood of 109 infertile women, 28 diagnosed with ovarian cancer, 24 with benign ovarian tumours or cysts, and 152 who were healthy.

Significant numbers of antibodies were found in women with premature ovarian failure, ovulatory problems and unexplained infertility, as well as those with ovarian cancer.

They were not found in women with the condition endometriosis, healthy women, or women with benign disease.

The findings are published in the online issue of the journal Cancer Epidemiology Biomarkers & Prevention.

Precisely how the antibodies are related to ovarian cancer is still unclear. The scientists still have to answer the question of whether the molecules are a reaction to or a cause of the disease.

Prof Luborsky said: “We think that antibodies may arise in response to very early abnormal changes in ovarian tissue that may or may not progress to malignancy, depending on additional triggering events.

“Or, alternatively, antibodies may bind to normal cells in the ovary, causing dysfunction and leading to infertility - and, in a subpopulation of women, to the development of ovarian cancer.”

Earlier this month scientists from the Institute of Cancer Research identified a rare genetic fault that raises a woman’s risk of developing ovarian cancer six-fold.

The discovery, described as a “landmark”, may provide another route to early diagnostic tests and could also lead to new personalised treatments.

New national guidelines published earlier this year called for GPs to carry out simple blood tests which check for signs of the illness to allow faster diagnosis and referral for specialist treatment.

A third of sufferers currently wait more than six months for an accurate diagnosis of the condition which is the UK’s fourth biggest cancer killer in women.

The test to measure the level of a protein called CA125 should be given to women particularly those aged over 50 if they have persistent symptoms of bloating, feeling full quickly, lower abdominal pain and needing to urinate urgently or frequently.

Based on these results, women should each then be offered an ultrasound scans of their abdomen and pelvis.