Risk factors and causes

Scientists continue to study the genes responsible for familial ovarian cancer. This research is beginning to yield clues about how these genes normally work and how disrupting their action can lead to cancer. This information eventually is expected to lead to new drugs for preventing and treating familial ovarian cancer.

Research in this area has already led to better ways to detect high-risk genes and assess a woman's ovarian cancer risk. A better understanding of how genetic and hormonal factors (such as oral contraceptive use) interact may also lead to better ways to prevent ovarian cancer.

Prevention

New information about how much BRCA1 and BRCA2 gene mutations increase ovarian cancer risk is helping women make practical decisions about prevention. For example, mathematical models have been developed that help estimate how many years of life an average woman with a BRCA mutation might gain by having both ovaries and fallopian tubes removed to prevent a cancer from developing. A recent study showed that fallopian tube cancers develop in women with BRCA gene mutations more often than doctors had previously suspected. However, it is important to remember that although doctors can predict the average outcome of a group of many women, it is still impossible to accurately predict the outcome for any individual woman.

Other studies are testing new drugs for ovarian cancer risk reduction

Researchers are constantly looking for clues such as lifestyle, diet, and medicines that may alter the risk of ovarian cancer.

Early detection

Accurate methods for detecting ovarian cancer early could have a great impact on the cure rate. Researchers are testing new ways to screen women for ovarian cancer, and a national repository for blood and tissue samples from ovarian cancer patients is being established to aid in these studies. One method being tested is looking at the pattern of proteins in the blood (called proteomics) to find ovarian cancer early.

From time to time, lab companies have marketed unproven tests to look for early ovarian cancer. Because these tests had not yet been shown to help find early cancer, the FDA told the companies to stop selling them. So far, this occurred with 2 different tests looking at protein patterns: OvaSure and OvaCheck. Both were taken off the market at the request of the FDA.

Two large studies of screening have recently been completed. One was in the United States, and the other was in the United Kingdom. Both studies looked at using the CA-125 blood test along with ovarian (transvaginal) ultrasound to find ovarian cancer. These studies have found early cancers in some women. But it is not known whether the outcomes of these women have been improved compared with women who haven't undergone screening.

Diagnosis

A new test called OVA1 has recently been approved by the FDA. It measures the levels of 4 proteins in the blood of women who have an ovarian tumor. The levels of these proteins, when looked at together, are used to put women with tumors into 2 categories -- low risk and high risk. The women who are labeled low risk are not likely to have their tumor be cancer. The women who are called high risk are more likely to have a cancer, and so should have surgery performed by a specialist (a gynecologic oncologist). This test is NOT a screening test - it is only meant for use in women who have an ovarian tumor.

Treatment

Treatment research includes testing the value of currently available methods as well as developing new approaches to treatment.

New chemotherapy combinations that may help cancers resistant to current treatments are constantly being investigated.

For cancers to grow, blood vessels must develop to nourish the cancer cells. This process is called angiogenesis. Drugs have been developed that are useful in stopping cancer growth by preventing new blood vessels from forming. One drug, called bevacizumab (Avastin) has been able to shrink or slow the growth of advanced ovarian cancers. Trials to see if bevacizumab works even better when given along with chemotherapy have shown good results in terms of shrinking (or stopping the growth of) tumors. But there have been problems with patients developing holes in the bowel wall (perforations) during treatment. This complication can be fatal. Experts are still studying the safest way to give this drug with other chemotherapy.

Other targeted therapies are being studied including inhibitors of growth factors, which stimulate the growth of the cancer cells.

Poly(ADP-ribose) polymerases (PARPs) are enzymes that have been recently recognized as key regulators of cell survival and cell death. Drugs that inhibit PARP-1 help fight cancers in caused by mutations in BRCA1 and BRCA2. These drugs may make cancers in women without BRCA mutations more sensitive to radiation therapy and some kinds of chemotherapy (methylating agents and topoisomerase I inhibitors). Clinical trials are in progress to determine whether these drugs will improve outcomes for ovarian cancers that develop in women without BRCA mutations.

Another approach is to develop tumor vaccines that program the immune system to better recognize cancer cells. Also, antibodies that specifically recognize and attack ovarian cancer cells are being developed. Perhaps some or all of these approaches along with chemotherapy will lead to cures for this disease.

Consolidation therapy -- treatment following first line therapy to prevent recurrence -- is undergoing clinical trials. Some of these trials are using chemotherapy, growth factor inhibitors and monoclonal antibodies. Monoclonal antibodies are like the antibodies our bodies make to fight infection. These, however, are made in the laboratory and are directed against specific sites on the cancer cell. Studies are on-going.

Last Medical Review: 08/27/2009
Last Revised: 08/27/2009