Ovarian cancer may affect women of any age group, although it is more common in post-menopausal women. The type of ovarian cancer which occurs in adults is usually of the "epithelial" variety, a term which refers to the fact that this tumor starts in the surface epithelial covering of the ovary. Other types of ovarian tumors may develop, depending upon which type of cell gives rise to the cancer. For instance, younger women may develop ovarian "germ cell" tumors (which start in young cells similar to the eggs contained within the ovary), and older women may develop ovarian stromal cell tumors (like granulosa cell cancer) which start in the supporting tissue (stroma) contained within the ovary. It is important to distinguish between these various types of ovarian tumors, since the treatment approach may differ. In the following information, the term "ovarian cancer" will be used to describe the most common type of tumor seen in adults (namely, the epithelial variety).
Approximately 1 in 70 women will develop epithelial ovarian cancer each year in the United States, translating into about 27,000 new patients per year. Factors which are associated with lower risk of ovarian cancer include a history of birth control pill use, pregnancy, or breast feeding. The most important factor associated with increased risk for developing this tumor is a strong family history of ovarian and/or breast cancer, especially if these diseases occur at a young age and involve close family members (like a mother or sister, also known as "first degree relatives"). If you have a strong family history of these kinds of cancers, you may wish to take advantage of genetic counseling opportunities in your area (see section below entitled "Inheritance and Ovarian Cancer"). However, it is important to realize that most patients who develop ovarian cancer have no obvious risk factors.
Unfortunately, many patients with ovarian cancer experience no early warning signs. This is because the tumor may spread beyond the ovary to involve other areas within the pelvis and abdomen at a time when it is too small to be detected by the pelvic examination. Occasionally, the tumor is detected at an early stage by pelvic exam (see below for staging), sometimes in the setting of pelvic pain. More commonly, however, patients with ovarian cancer come to medical attention because of abdominal discomfort and bloating (often due to the presence of tumor outside of the ovary).
Once a pelvic mass is discovered by exam, your physician may order special tests such as a pelvic ultrasound to further evaluate the mass. If the ultrasound confirms the possibility of an ovarian tumor, a surgical procedure (oftentimes an exploratory laparotomy) is often performed to remove the mass for examination by the pathologist. If the mass appears to be malignant, it may be necessary to perform removal of the ovaries and fallopian tubes ("bilateral salpingo-oophorectomy") and removal of the uterus ("hysterectomy"). If the tumor has extended beyond the ovary to involve other sites in the pelvis and abdomen, an attempt is made to remove as much tumor as possible ("debulking"). This is done because patients who have only small amounts of tumor remaining tend to respond more favorably to post-operative treatments such as chemotherapy. During the operation, the surgeon may take small amounts of tissue from many different areas of the abdomen and pelvis ("biopsies") in order to determine the exact locations of the tumor. This will help to determine your tumor stage and guide further treatment decisions.
Patients may be diagnosed with one of four different stages of ovarian cancer
Approximately 30% of patients will be diagnosed with stage I or II tumors, and 70% of patients will have stages III or IV disease. Most patients with epithelial ovarian cancer have tumors that cannot be completely removed by surgery alone. Even in situations where all of the obvious tumor has been removed, there are often microscopic areas of tumor remaining which can grow back again if not treated. That is why the majority of patients with ovarian cancer will require some form of chemotherapy after the operation in an attempt to destroy any remaining tumor cells. Under rare circumstances, certain patients with early stage disease may not require further treatment. However, only your oncologist can advise you as to whether this approach is appropriate for your situation.
The present standard of care for treatment of patients who are felt to be appropriate candidates for post-operative chemotherapy is a combination of two kinds of chemotherapy agents. One kind is called the "taxanes" and includes drugs such as Taxol™ (paclitaxel) and Taxotere™ (docetaxel). The other kind is called "platinum" analogs and includes drugs such as carboplatin and cisplatin. A commonly used regimen is comprised of Taxol™ and carboplatin, often administered intravenously in the outpatient clinic once every 3 weeks for a total of 6 treatments (also known as "cycles"). Other combinations which have been used include Taxotere™ and carboplatin, or Taxol™ and cisplatin. These all represent active regimens, and the ultimate choice depends upon your physician's preference, as well as whether you are participating in a clinic trial (see below). You should discuss the details of chemotherapy, including side effects, with your physician.
Over 70% of patients who receive chemotherapy will experience a beneficial reduction in the size of residual tumor, oftentimes associated with a drop in the level of a blood test known as CA-125. CA-125 is a substance made by ovarian cancer cells, and its blood level drops as the tumor is destroyed. Unfortunately, many (but not all) patients experience regrowth of their tumor at some point in the future. At that time, retreatment with additional chemotherapy is often required, although obtaining good control of the tumor may be more difficult. This is due to the fact that recurrent tumors develop a certain amount of resistance to the effects of chemotherapy (a condition known as "drug resistance"). Several options are available for managing recurrent ovarian cancer, including retreatment with taxanes or platinum agents, or the use of different agents such as tamoxifen, topotecan, Doxil™, or etoposide. Your oncologist is in the best position to decide which of these agents would be most appropriate for your situation.
The realization that many patients with ovarian cancer experience recurrence of their tumor has lead to the need for better treatment approaches. In this regard, clinical trials testing new treatments for ovarian cancer may be available for patients who wish to participate and who meet the eligibility criteria. It is important to remember, however, that there is currently (as of March 1999) no treatment approach for patients with newly-diagnosed disease that is convincingly better than the standard chemotherapy described above. That is why clinical trials are called "investigational." Nevertheless, new treatments which are studied in the setting of clinical trials may eventually prove to be better than standard approaches. You or your physician may wish to discuss the possibility of clinical trial participation with our staff, who would be happy to assist you. Also, an excellent web site which further describes the importance of clinical trial participation may be found at the following address: http://cancertrials.nci.nih.gov/.