Women diagnosed with ovarian cancer have a variety of treatment options, including surgery, chemotherapy, hormone therapy, targeted therapy, immunotherapy and radiation. Most often, patients receive combinations of these treatments.
When a woman is first diagnosed with ovarian cancer, the treatment program corresponds to the cancer’s stage. More advanced cancers generally require more aggressive treatments.
Ovarian cancer treatment can be fine-tuned based on information about the patient and her tumor’s molecular characteristics. It is known that germline (hereditary) mutations in BRCA1 and BRCA2 genes increase the risk of developing ovarian cancer. The standard of care is to test for mutations in these genes whenever a woman is diagnosed with ovarian cancer – even if there is no family history. If her test is positive, drugs called PARP inhibitors can be effective in treating her cancer or used in maintenance to keep the cancer from coming back.
In addition, Tumor Profiles – diagnostic tests that identify the molecular characteristics of each patient’s tumor – can inform treatment decisions. National Comprehensive Cancer Network (NCCN) guidelines recommend that all patients obtain tumor testing for mutations in BRCA 1/2 and another genomic biomarker called homologous recombination deficiency (HRD) because positive results suggest benefit from treatment with PARP inhibitors. If there is a recurrence, testing for a biomarker called microsatellite instability (MSI) is also recommended, particularly for women who have cancers with clear cell and endometrioid histology. A positive MSI test suggests benefit from treatment with an immune checkpoint inhibitor.
Here are the most common treatment options:
- Surgery is conducted to diagnose (confirm that it is cancer), stage (determine how far it has spread) and remove as much tumor as possible. This is called debulking the tumor. In most cases, surgeons remove the uterus, ovaries and fallopian tubes and take samples (or biopsies) from the surface of other tissues inside the pelvic and abdominal cavities. Unfortunately, surgery rarely gets all of the cancer, which means patients must have additional treatments.
- Chemotherapy damages tumor DNA to foster cell death or interferes with other important cellular mechanisms. Tumor cells are particularly susceptible to this damage since they divide more often than most normal cells. Unfortunately, the DNA in normal cells can also be damaged. Chemotherapy is a systemic treatment, which means it is infused through the blood and goes throughout the body. Most ovarian cancers are treated with a platinum compound to damage DNA, such as carboplatin, and a taxane to interfere with cell division, such as paclitaxel (Taxol).
- Radiation therapy (also called radiotherapy) uses high doses of radiation to kill cancer cells. Radiation is more targeted than chemotherapy, which can be an advantage or a disadvantage. Though it may do less systemic damage, it could also miss some of the cancer. It is most often used palliatively to shrink tumors when they are causing painful symptoms.
- Because hormones can stimulate growth in some ovarian cancers, there are a number of therapies designed to prevent tumors from being triggered by them. For example, tamoxifen, which is more often used to treat breast cancer, can be used to block estrogen activity in tumor cells. Other drugs, like letrozole (Femara) reduce estrogen production. Such estrogen-blocking therapy is often used for a type of ovarian cancer called Low Grade Serous.
- Targeted therapies work by hitting specific proteins and enzymes that help tumors survive and grow. Bevacizumab (Avastin) targets a protein called Vascular Endothelial Growth Factor (VEGF), which stimulates the growth of blood vessels to help feed growing tumors. Poly ADP Ribose Polymerase (PARP) inhibitors, such as olaparib (Lynparza), niraparib (Zejula) and rucaparib (Rubraca), interfere with DNA repair mechanisms. The goal is to increase the amount of DNA damage in tumor cells so that they die.