Stage I Ovarian Cancer
Patients diagnosed with Stage I ovarian cancer have cancer that is limited to the ovaries and has not spread to other pelvic or abdominal organs, lymph nodes or sites outside of the abdomen.
A variety of factors ultimately influence a patient’s decision to receive treatment of cancer. The purpose of receiving cancer treatment may be to improve symptoms through local control of the cancer, increase a patient’s chance of cure, or prolong a patient’s survival. The potential benefits of receiving cancer treatment must be carefully balanced with the potential risks of receiving cancer treatment.
The following is a general overview of the treatment of Stage I ovarian cancer. Circumstances unique to your situation and prognostic factors of your cancer may ultimately influence how these general treatment principles are applied. The information on this Web site is intended to help educate you about your treatment options and to facilitate a mutual or shared decision-making process with your treating cancer physician.
Most new treatments are developed in clinical trials. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Participation in a clinical trial may offer access to better treatments and advance the existing knowledge about treatment of this cancer. Clinical trials are available for most stages of cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. To ensure that you are receiving the optimal treatment of your cancer, it is important to stay informed and follow the cancer news in order to learn about new treatments and the results of clinical trials.
Stage I ovarian cancer is curable in the majority of patients with optimal surgical removal of the cancer. Despite surgical removal of the cancer, 5-20% of patients with Stage I ovarian cancer will experience a recurrence of their cancer. This is because some patients with Stage I cancer have microscopic cancer cells that have spread outside the ovary and therefore were not removed by surgery. Undetectable areas of cancer outside the ovary are referred to as micrometastases. The presence of these micrometastases causes the relapses that follow treatment with surgery alone. Following surgery, some patients may benefit from additional treatment with chemotherapy to further decrease the risk of cancer recurrence.
Because small amounts of cancer may have spread into the lymph nodes and were not removed during surgery, an effective treatment is needed to cleanse the body of micrometastases in order to improve a patient’s duration of survival and potential for cure. The delivery of cancer treatment following local treatment with surgery is referred to as “adjuvant” therapy and may include chemotherapy, radiation therapy and/or biologic therapy.
Following surgery, adjuvant chemotherapy for ovarian cancer is administered to decrease the risk of cancer recurrence. Chemotherapy typically involves the administration of one or more anti-cancer drugs following recovery from surgery. Some, but not all, clinical trials have demonstrated that adjuvant chemotherapy treatment for patients with Stage I ovarian cancer improves survival compared to treatment with surgery alone. Several factors may affect an individual’s decision regarding the type of primary chemotherapy to receive. Patients at a low risk of cancer recurrence may consider less aggressive therapy or may opt not to receive any additional treatment, whereas patients at a high risk of cancer recurrence may choose more aggressive therapies or participate in clinical studies evaluating innovative treatment strategies.
Low-Risk Stage I Ovarian Cancer
Patients with Stage I ovarian cancer are considered to be at low risk of cancer recurrence if the cancer appears to be of low or moderate grade (aggressiveness) under a microscope and no cancer cells were found in the abdominal fluid or on the surface of the ovary. Local treatment with surgery cures the majority of individuals with low-risk Stage I ovarian cancer. A few patients, however, will already have developed micrometastases.
Some women with low-risk Stage I ovarian cancer will not require chemotherapy. For women who do receive chemotherapy, however, treatment typically consists of a combination of paclitaxel and a platinum chemotherapy compound (Paraplatin® or Platinol®).
High-Risk Stage I Ovarian Cancer
Patients with Stage I ovarian cancer are considered high-risk if the cancer appears high-grade under the microscope, has a “clear cell” histology or if cancer cells were found in the abdominal fluid or on the surface of the ovary. Although local treatment with surgery cures the majority of individuals with high-risk Stage I ovarian cancer, up to 40% of patients may experience recurrence.
Some, but not all, clinical trials have shown a further reduction in cancer recurrence following adjuvant chemotherapy treatment in patients with high-risk Stage I ovarian cancer. Approximately 80% of patients with high-risk Stage I ovarian cancer treated with surgery and adjuvant chemotherapy will be alive and without evidence of cancer 5 years from surgery.
Before deciding to receive adjuvant chemotherapy treatment, women should ensure that they understand the answer to the following 3 questions:
- What is my prognosis (risk of cancer recurrence) without adjuvant chemotherapy treatment?
- How will my prognosis be improved with chemotherapy treatment?
- What are the risks of chemotherapy treatment?
When individuals with Stage I ovarian cancer elect to be treated with adjuvant chemotherapy, a treatment regimen must be selected. Clinical studies have demonstrated that the use of the chemotherapy agent paclitaxel combined with Platinol® (cisplatin) improves the outcome of patients with advanced ovarian cancers. More recently, clinical studies have also shown that another platinum compound, Paraplatin® (carboplatin), has fewer side effects than Platinol, but cures an equal number of patients. Although these paclitaxel-containing regimens have not been evaluated against other chemotherapy combinations specifically in patients with early-stage ovarian cancer, most doctors feel the superior experience with paclitaxel and Paraplatin® in advanced-stage ovarian cancer justifies its use in patients with high-risk early-stage cancer.
Although paclitaxel-Paraplatin® or paclitaxel-Platinol® are considered standard chemotherapy regimens for high-risk Stage I ovarian cancer, the optimal length of treatment has yet to be determined.
Strategies to Improve Treatment
The progress that has been made in the treatment of ovarian cancer has resulted from improved development of adjuvant chemotherapy treatments and doctor and patient participation in clinical studies. Future progress in the treatment of ovarian cancer will result from continued participation in appropriate studies. Currently, there are several areas of active exploration aimed at improving the treatment of Stage I ovarian cancer.
Supportive Care: Supportive care refers to treatments designed to prevent and control the side effects of cancer and its treatment. Side effects not only cause patients discomfort, but also may prevent the optimal delivery of therapy at its planned dose and schedule. In order to achieve optimal outcomes from treatment and improve quality of life, it is imperative that side effects resulting from cancer and its treatment are appropriately managed. For more information, go to Managing Side Effects.
Refinement of Treatment Regimens: Paclitaxel can be administered to patients using a variety of differing doses and schedules. Paclitaxel had been commonly administered in the hospital over a course of 24 hours. Paclitaxel is now often given over 3-hour infusions on an outpatient basis. Determining the optimal schedule and dose for paclitaxel administration is still an active area of investigation. Current clinical trials are testing whether 2 months (3 cycles) of chemotherapy is as effective as 4 months (6 cycles) of chemotherapy. Patients should discuss the potential risks and benefits of these regimens with their doctor.
Evaluation of Adjuvant Chemotherapy: Since some, but not all, clinical trials have demonstrated improved survival with adjuvant chemotherapy treatment in patients with Stage I ovarian cancer, there remains controversy concerning the necessity of treating all women. Clinical trials are currently ongoing to compare modern adjuvant chemotherapy treatment regimens to no additional therapy in women with low-risk Stage I ovarian cancer.