Stage I Uterine Cancer
Patients diagnosed with Stage I uterine cancer have cancer that has not spread outside the uterus.
Stage IA is cancer confined to the inner layer of cells of the uterus (endometrium). Stage IB is cancer that invades less than one half of the muscle wall of the uterus. Stage IC is cancer that invades more than one half of the muscle wall of the uterus.
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 uterine 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 uterine cancer is curable with surgery alone for the majority of patients. Optimal treatment may require additional therapeutic approaches in selected situations. Thus, it is important for patients to be treated at a medical center that can offer multi-modality treatment from gynecologic oncologists and radiation oncologists.
The standard treatment for stage I uterine cancer is a total abdominal hysterectomy (removal of the uterus) and bilateral salpingo-oophorectomy (removal of the fallopian tubes and ovaries) with or without removal of the pelvic and para-aortic lymph nodes. Despite complete surgical resection of all cancer, 5-20% of patients will experience recurrence of their cancer. This is because some patients with stage I cancer have microscopic cancer cells, called micrometastases, that have spread outside the uterus and therefore were not removed by surgery. These cancer cells cannot be detected with any of the currently available tests. The presence of these micrometastases causes relapses that follow treatment with surgery alone. Following surgery, some patients may benefit from additional treatment (adjuvant therapy) to decrease the risk of cancer recurrence. There is a progressive increase in local and distant cancer recurrences in patients with stage IA, IB and IC disease and in patients with well, moderately and poorly differentiated cancers following treatment with surgery alone. To learn more about surgery, go to Surgery & Uterine Cancer.
Adjuvant therapy is the delivery of cancer treatment following local treatment with surgery and may include chemotherapy, radiation therapy and/or biologic therapy. Although it is still being evaluated in clinical trials, many patients with stage IB and IC uterine cancer are often treated with adjuvant radiation therapy. When the uterus is surgically removed, the cut ends of the vagina are surgically sewn together forming a “vaginal cuff”. The vaginal cuff is a common site of local cancer recurrence following treatment with surgery alone. The goal of radiation therapy is to eradicate any remaining cancer cells after surgery. Adjuvant radiation therapy may consist of brachytherapy and/or external beam radiation. Women with stage I uterine cancer treated with surgery and postoperative radiation therapy have a 5-year survival of 80-90% and a local cancer recurrence rate of only 4-8%.
Adjuvant External Beam Radiation Therapy: External beam radiation therapy (EBRT) is given via machines called linear accelerators, which produce high-energy external radiation beams that penetrate the tissues and deliver the radiation dose deep into the areas where the cancer resides.
A large clinical trial that involved 715 women with stage I uterine cancer compared treatment with surgery alone or treatment with surgery followed by adjuvant external beam radiation therapy. These women had deep invasion of the muscle wall of the uterus and/or had high-grade (more aggressive) types of cancer. The cancer recurrence rates were 4% for patients treated with surgery and radiation and 14% for patients treated with surgery alone. Survival rates, however, were 81% for treatment with surgery and adjuvant radiation therapy and 85% for surgery alone. Although patients treated with surgery and radiation experienced fewer cancer recurrences, patients treated with surgery alone survived longer. This is because there were more side effects in women treated with radiation therapy. The doctors concluded that postoperative radiation therapy reduced local recurrences of cancer following surgery for stage I uterine cancer, but did not improve survival.
Adjuvant Brachytherapy: Brachytherapy treatment involves the placement of a radioactive isotope into the vagina and may have fewer side effects than external beam radiation. Brachytherapy delivers radiation therapy at a very high dose rate in 3 weekly treatments to the “vaginal cuff” region. Brachytherapy without external beam radiation therapy has been used to prevent local recurrences after surgery. In a clinical trial that involved 102 women with stage IB and IC uterine cancer who were treated with brachytherapy following surgery, cancer recurrences occurred in 7% of women, 4% of which were local recurrences. Of the 3 local recurrences, only one occurred in the vaginal cuff. The survival at 5 years was 84%. Brachytherapy alone appeared very effective for preventing local cancer recurrences without the major side effects associated with external beam radiation.
Researchers in Florida have also evaluated outcomes of 396 women with stage I uterine cancer treated with hysterectomy, lymph node dissection and brachytherapy. Following treatment, 5-year survival was 100% for patients with stage IA cancer, 97% for patients with stage IB cancer and 93% for patients with stage IC cancer. All cancer recurrences occurred at distant sites that would not have been treated in an external beam radiation field. These studies suggest that brachytherapy alone is as effective for the treatment of stage I uterine cancer as external beam radiation therapy.
However, since these clinical trials did not directly compare brachytherapy to brachytherapy plus hysterectomy, it remains unknown whether hysterectomy plus brachytherapy definitely improves survival compared to surgery alone. This is because treatment of a local cancer recurrence in patients initially treated with surgery can be accomplished with additional surgery and/or radiation. A strategy utilizing initial treatment with surgery alone followed by additional surgery or radiation therapy only for the 5-20% of patients who experience a local cancer recurrence would spare the majority of women with stage IB and IC uterine cancer from radiation treatment. For patients who do not receive radiation therapy, frequent examinations are necessary because 5-20% of patients will experience a local cancer recurrence following treatment with surgery alone. It is important to detect recurrences early.
Strategies to Improve Treatment
The progress that has been made in the treatment of stage I uterine cancer has resulted from the development of multi-modality treatments and doctor and patient participation in clinical trials. Future progress in the treatment of stage I uterine cancer will result from continued participation in appropriate clinical trials. Currently, there are several areas of active exploration aimed at improving the treatment of uterine 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 Supportive Care.
Improved Staging: Undetected spread of cancer can lead to under-treatment of uterine cancer. One method for detecting the spread of cancer is examination of cells floating free in the peritoneum (pelvis). This is done by injecting a salt solution into the abdomen, allowing it to mix thoroughly and then removing it for examination under the microscope. However, it is sometimes difficult to distinguish normal cells from cancer cells when using this method.
Monoclonal antibodies are proteins that can locate cancer cells and bind to them, thereby enabling the pathologist to better distinguish cancer cells from normal cells. The use of monoclonal antibodies to identify cancer cells in the peritoneum may improve the accuracy of staging and help identify patients requiring more aggressive treatment.
Trials of Adjuvant Chemotherapy: There has been significant progress in the identification of patients with stage I uterine cancer that are likely to experience cancer recurrence after treatment with surgery. Radiation therapy prevents some but not all local cancer recurrences, but does not prevent any recurrences outside the radiation field. Clinical trials are ongoing to evaluate the use of adjuvant chemotherapy in patients at a high risk of cancer recurrence.
Primary Treatment with Hormonal Therapy: Research indicates that uterine cancers that are more differentiated (lower grade) respond to hormonal treatment. Historically, hormonal therapy drugs have been used to decrease symptoms in women with advanced or recurrent uterine cancer. More recentl, hormonal therapy has been used to treat some younger women with well-differentiated stage I uterine cancer in order to avoid hysterectomy.
In one study, 29 women (17 with atypical hyperplasia and 12 with well-differentiated uterine cancer) were treated with hormonal therapy consisting of one of the progestin drugs. The results indicated that 16 of the 17 women with atypical hyperplasia and 9 of the 12 women with well-differentiated uterine cancer experienced regression of their disease. The average time to produce complete regression was 9 months. At an average follow-up of 40 months, all patients were alive without evidence of progressive cancer. Treatment of atypical hyperplasia and well-differentiated carcinoma of the uterus with progestins may be a safe alternative to hysterectomy in women under the age of 40.