Ovarian Cancer Research
What is new in ovarian cancer research and treatment?
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.
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.
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 isn’t known whether the outcomes of these women have been improved compared with women who haven't undergone screening.
A test called OVA1 is meant to be used in women who have an ovarian tumor. It measures the levels of 4 proteins in the blood. 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 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.
Some women with epithelial ovarian cancer have normal levels of the tumor marker CA125. In these women, the only way to tell if treatment is working (or to see if the cancer has come back) is to do imaging studies (like CT scans). Experts have found that in many women with ovarian cancer, the blood level of a protein called HE4 is increased. If you have ovarian cancer and a normal CA125 level, your doctor may decide to check the HE4 level. If it is high, it can be used instead of CA125 to guide 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. Studies are also looking at using targeted therapy drugs to fight ovarian cancer.
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 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, monoclonal antibodies that specifically recognize and attack ovarian cancer cells are being developed. These antibodies are man-made versions of the antibodies our bodies make to fight infection. They can be designed to home in on certain sites on the cancer cell. Farletuzumab is a monoclonal antibody that is directed against a protein on the surface of ovarian cancer cells. It has shown promise in treating ovarian cancer in early studies. Another monoclonal antibody being studied in ovarian cancer is called catumaxomab. It binds to a protein that is in some cancer cells and some immune system cells. When it is administered into the abdominal cavity, it can help treat fluid build up (ascites) that can occur when cancer is present.
Consolidation therapy -- treatment following first line therapy to prevent recurrence -- is being tested in clinical trials. Some of these trials are using chemotherapy, growth factor inhibitors and monoclonal antibodies. Studies are on-going.
Information provided by the American Cancer Society