The use of brachytherapy (radioactive implants) after surgery for stage I endometrial cancer appears to help prevent cancer recurrences in the area of the uterus, according to a new study by Arizona researchers. This finding offers hope for an effective alternative to external-beam radiation therapy for women with this disease.
Cancer of the endometrium is characterized by the presence of cancer cells in the lining of the uterus, or womb. Treatment options depend on many factors, including the stage (extent of disease at diagnosis) of disease. Stage IA endometrial cancer is defined as cancer that is confined to the inner layer of cells of the uterus. Stage IB is described as cancer that involves less than one half of the muscle wall of the uterus. Stage IC is cancer that involves more than one half of the muscle wall of the uterus, but is confined to this area. The standard primary treatment of stage IA-IC cancers of the endometrium is surgery to remove the uterus (called total abdominal hysterectomy) as well as the ovaries and fallopian tubes (called bilateral salpingo-oophorectomy). As part of the surgical removal of the uterus, the upper ends of the vagina are sewn together, forming what is the vaginal cuff. In cases in which there is a recurrence (return) of the cancer later, it often occurs in the vaginal cuff.
To help prevent a recurrence of cancer, some women with stage I endometrial cancer may receive radiation therapy or chemotherapy after surgery (called adjuvant therapy); however, the role of such therapy is still under study. There is a progressive increase in the risk for recurrence of endometrial cancer after surgery for patients with stage IA, IB, and IC disease, making adjuvant therapy potentially beneficial. However, thus far studies on adjuvant radiation therapy have been inconclusive. In 1 study, external-beam radiation therapy (radiation emitted from an external machine) and brachytherapy (placement of radioactive implants in or near the cancer) were found to decrease the likelihood of a cancer recurrence in the uterus; however, the added therapy did not improve survival. Further studies are needed to determine the value of such adjuvant therapies, especially because the treatment of patients who have a recurrence after surgery alone is often successful, while those who have a recurrence after adjuvant radiation therapy often do not respond as well to further treatment. In addition, external-beam radiation therapy can cause significant side effects in some persons. Overall, the 5-year survival rate for women with stage I endometrial cancer who undergo surgery and adjuvant radiation therapy is 80 to 90%, with a 4 to 8% incidence of cancer recurrence in the uterus.
Researchers in Arizona treated 102 women who underwent surgery for stage IB and IC cancer of the endometrium. After surgery, all patients received 3 weekly treatments of high-dose brachytherapy, with placement of the radioactive implants in the vaginal cuff. The results showed that 7% of the patients experienced a recurrence of cancer, with only 4% occurring in the area of the uterus. Of the 3 cancer recurrences in area of the uterus, only 1 occurred in the vaginal cuff. After 5 years, 84% of the women were alive. No major side effects were observed.
These researchers concluded that adjuvant brachytherapy appears to be well tolerated and highly effective in preventing cancer recurrences in the area of the uterus in women with stage IB and IC endometrial cancers. Further studies are needed to compare this regimen directly to that of surgery followed by external-beam radiation therapy and other adjuvant therapies. These findings do offer the hope that women with stage I endometrial cancer can be spared the side effects of external-beam radiation therapy. Persons who have this type of disease may wish to talk with their doctor about the risks and benefits of participating in a clinical trial (research study) in which high-dose brachytherapy or another promising new adjuvant therapy is being studied. Sources of information on ongoing clinical trials include clinical trials listing services provided by the National Cancer Institute (cancer.gov). (International Journal of Radiation Oncology and Biologic Physics, Vol 46, No 2, pp 417-425, 2000).