Ovarian Cancer Treatments: What You Should Know
Good news: Researchers are making real progress in ovarian cancer treatment that is "complex, dynamic, and exciting," says Ursula Matulonis, M.D., director and chief of the Division of Gynecologic Oncology at Dana-Farber Cancer Institute and professor of medicine at Harvard Medical School. "Our understanding of ovarian cancer has led to notable improved outcomes and treatments."
Here, Dr. Matulonis shares more about treating ovarian cancer, a disease diagnosed in approximately 22,440 women each year.
There are five different types of ovarian cancer
Ovarian cancer isn't just one disease, says Dr. Matulonis. It can be "split" into roughly five subsets based on the pathology of the cancer, with the most common type, more than 75 percent, being high-grade serous carcinoma. Approximately 22 percent of patients with high-grade serous cancer have some underlying BRCA1 or BRCA2 gene, and more than 50 percent of these cancers have some underlying DNA repair defect.
How BRCA and other mutations affect ovarian cancer treatment
Specific inherited mutations, like BRCA, that lead to ovarian cancer can either occur within the patient (called germline) or only within their cancer (called somatic or acquired mutations), Dr. Matulonis says. At diagnosis, these mutations make you most susceptible to platinum-based chemotherapy because of little "breaks" in the DNA or genetic code.
High-grade serous cancer treatment
High-grade serous cancers can relapse and become more resistant to chemotherapy, says Dr. Matulonis. Drugs called poly-ADP-ribose polymerase (PARP) inhibitors have transformed treatment in this subtype, especially for people with inherited gene mutations, by blocking the PARP enzyme that cells normally use to repair DNA damage. PARP inhibitors are approved for recurrent ovarian cancer as maintenance following response to platinum chemotherapy and BRCA-mutated cancer treatment.
Low-grade serous cancer treatment
"These cells look different from high-grade serous under the microscope," Dr. Matulonis says. "They have more chemo insensitivity and possess that 'Achilles heel' or weakness of having underlying DNA repair problems. That means they can also be more sensitive to hormonal therapies, such as drugs like aromatase inhibitors, used to treat breast cancer." This type of cancer is considered a rare tumor, occurring in approximately 10 percent of cases.
Three other sub-types of ovarian cancer
Mucinous tumors are another type of ovarian cancer, says Dr. Matulonis, and they’re less responsive to chemotherapy than other ovarian cancers. Clear cell cancer, on the other hand, is "chemo-insensitive," meaning it's more receptive to chemo. Lastly, both high- and low-grade endometrioid cancers in the ovaries are often associated with endometriosis, as are clear cell tumors.
The process of ovarian cancer treatment
A diagnosis of ovarian cancer is made by biopsy. Traditionally, this is followed by surgery called debulking, performed by a gynecologic oncologist. Next comes six cycles of chemotherapy, usually with carboplatin and paclitaxel.
Another, newer option is a type of therapy called neoadjuvant chemotherapy; this may be recommended to "shrink" the tumor pre-surgery, followed by more chemotherapy. "This is utilized in women who have advanced stage 3 or 4 cancer," Dr. Matulonis says. Radiation therapy is not usually used for ovarian cancer.
More on new ovarian treatments: Biologics
There are other new treatments for ovarian cancer available, Dr. Matulonis says. For example, biologic agents such as bevacizumab can be combined with carboplatin/paclitaxel in newly diagnosed patients. Biologic agents employ the body's immune system to fight cancer cells. These antivascular agents shut down blood vessels that "feed" cancers during a process called angiogenesis.
Recurring ovarian cancer: Things to know
More than 80 percent of patients with advanced stage ovarian cancer will have a recurrence of their primary cancer. In recurrent cancer, chemotherapy, anti-angiogenic agents, and PARP inhibitors are used, and immunological therapies are currently being tested, she says. Recurrence doesn't usually have symptoms, and it’s detected by presence of the CA125 anti-cancer antigen in the blood.
What you can do to be proactive about ovarian cancer
Surprisingly, perhaps, the number of women diagnosed with ovarian cancer hasn't changed much in the past 10 years, Dr. Matulonis says. "We don't have an early detection test. We do have a preventative test if someone is diagnosed with a germline BRCA mutation. If a woman is found to have that, she may undergo prophylactic surgery to remove the ovaries and fallopian tubes as well as consideration of mastectomies. That doesn't reduce risk to zero, but it does greatly reduce risk."
Genetic testing for BRCA mutations can help your family
That genetic testing can be crucial, says Dr. Matulonis. "I recommend genetic testing for any woman with ovarian cancer, regardless of age, family history, or type of ovarian cancer. We now know that there are at least 11 genes that can contribute to ovarian cancer, including BRCA1 and BRCA2. Someone who's diagnosed can help family members and that can then drive treatment."
Making smart and efficient decisions about ovarian cancer treatment
All major decisions around treatment should be made with your gynecologic oncologist, ideally at an academic medical center, Dr. Matulonis says. "But a person diagnosed cannot waste time," she says. "If surgery and chemotherapy are complete, you should be followed in a place that understands this cancer and its treatment if it recurs. An academic medical center will also have access to clinical trials that offer the newest treatments and procedures."