Medically reviewed by Dr. C.H. Weaver M.D. Medical Editor (08/2018)
Stage I ovarian cancer is limited to the ovaries and has not spread to other pelvic or abdominal organs, lymph nodes or sites outside of the abdomen. Each person with ovarian cancer is unique, and the specific characteristics of your condition will determine how it is managed.
Stage I ovarian cancer is curable in the majority of patients with optimal surgical removal of the cancer and systemic therapy. 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. Following surgery, some patients may benefit from additional systemic therapy to further decrease the risk of cancer recurrence.
Adjuvant Systemic Therapy
The delivery of cancer treatment following local treatment with surgery is referred to as “adjuvant” therapy and may include chemotherapy, precision cancer medicines, radiation therapy and/or immunotherapy.
Adjuvant chemotherapy is administered to decrease the risk of cancer recurrence following recovery from surgery because 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. For women who do receive chemotherapy, however, treatment typically consists of a combination of platinum and taxane chemotherapy regimen.
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. Up to 40% of patients with high risk stage I cancer may experience recurrence so chemotherapy is routinely administered. Approximately 80% of patients with high-risk stage I ovarian cancer treated with surgery and adjuvant chemotherapy survive without evidence of cancer 5 years from surgery and chemotherapy treatment.
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?
Strategies to Improve Treatment
The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. In addition to continued development of chemotherapy treatment regimens active investigation aimed at improving the treatment of early stage ovarian cancer includes the following:
Development of Precision Cancer Medicines: Research is ongoing to develop new medications that specifically target cancer cells in clinical trials. These trials typically require a sample of the cancer or liquid biopsy to be available in order to evaluate for biomarkers. Patients should learn about options to participate in these trials prior to surgery in order to ensure that cancer tissue is obtained correctly. Learn more about development of precision cancer medicines for treatment of ovarian cancer.
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.