Ovarian cancer test on its way?
Ovarian cancer is the fifth most diagnosed cancer among Canadian women, accounting for about four per cent of all new cancer cases each year.
It also is the fifth leading cause of cancer death for women in Canada, accounting for about five per cent of deaths, despite being very treatable in the early stages.
The high death rate is because ovarian cancer is rarely diagnosed before it spreads beyond the ovaries. Symptoms of ovarian cancer are vague – abdominal bloating, nausea, indigestion, gas, constipation, diarrhea or frequent urination, unusual fatigue, unexplained weight loss or shortness of breath – and often missed by patients and doctors.
But now a genetic test may be able to identify women who are likely to get ovarian cancer, before they do.
The search for genetic link
Researchers at the Oregon Health & Science University Cancer Institute knew that although some women do not have mutations in the genes responsible for these cancers, they still had a strong family history of ovarian and/or breast cancer.
They believed that there must be a genetic component that could be tracked. nd it appears that they were right.
In the study the team collected samples of ovarian tissue (with permission) from 22 patients – women who were undergoing benign gynecological diseases, ovarian cancer patients, and from women at high risk of ovarian cancer who were having their ovaries removed as a preventative measure.
There were women at high risk of developing ovarian cancer due to a family history of breast and ovarian cancer, and a control group of women with no family history of the cancer in the study.
Lack of protein
What the researchers found was that women at high risk of ovarian cancer have a low level of a protein known as FANCD2. Normally this protein protects DNA and helps repair broken chromosomes. But cells from the ovary in at-risk women were unable to be repaired. So well before cancers developed, the cells from the ovary were at high risk of developing cancer-causing mutations.
This means it may be possible to develop a screening method involving minor surgery.
“Once this method is fully developed, we will be able to tell a young woman who has a family history of ovarian or breast cancer, but who wants to have children, whether she is at risk or not, without removing her ovary,” says lead researcher Tanja Pejovic, M.D., Ph.D., associate professor of obstetrics and gynecology, OHSU School of Medicine, and one of the founding members of the Center for Reproductive Malignancies of the OHSU Cancer Institute.
The study “”Cytogenetic Instability in Ovarian Epithelial Cells From Women at Risk of Ovarian Cancer,” was published in the September 15, 2006 issue of the journal Cancer Research. Pejovic says that the next step is to apply her findings in a large multi-institute study.