Among women who have undergone surgery for high-intermediate risk endometrial cancer, vaginal brachytherapy is as effective as pelvic external beam radiotherapy in the prevention of vaginal recurrence and produces fewer side effects. These results were published in Lancet.
After surgery, additional treatment with radiation therapy can reduce the risk of locoregional cancer recurrence (recurrence in the vagina or pelvis) among women at higher risk of recurrence. Radiation therapy is often delivered by external beam radiation therapy to the pelvis, but this approach can result in side effects such as diarrhea.
Because the vagina is a common site of endometrial cancer recurrence, researchers conducted a study known as PORTEC-2 to compare vaginal brachytherapy to external beam radiation therapy among women with high-intermediate risk endometrial cancer. Vaginal brachytherapy involves the placement of radioactive material within the vagina. The hope was that vaginal brachytherapy would provide a similar level of cancer control as external beam radiation therapy, with fewer side effects.
The study enrolled 427 women from 19 Dutch radiation oncology centers. The women had Stage I or IIA high-intermediate risk endometrial cancer. After surgery, the women were assigned to receive radiation therapy with either pelvic external beam radiation therapy or vaginal brachytherapy. The primary outcome of interest was the rate of vaginal recurrence.
- Estimated five-year risk of vaginal recurrence was 1.8% among women treated with vaginal brachytherapy and 1.6% among women treated with external beam radiation therapy.
- Estimated five-year risk of vaginal or pelvic recurrence or both was 5.1% among women treated with vaginal brachytherapy and 2.1% among women treated with external beam radiation therapy.
- Overall and disease-free survivals were similar in the two groups.
- Rates of gastrointestinal side effects were lower among women treated with vaginal brachytherapy than among women treated with external beam radiation therapy (12.6% versus 53.8%).
The results indicate that vaginal brachytherapy is as effective as external beam radiation therapy at reducing the risk of vaginal recurrence, and also produces fewer side effects. The researchers conclude: “[Vaginal brachytherapy] should be the adjuvant treatment of choice for patients with endometrial carcinoma of high-intermediate risk.” These results do not apply to patients with high-risk or advanced disease.
 Nout RA, Smit VTHBM, Putter H et al. Vaginal brachytherapy versus pelvic external beam radiotherapy for patients with endometrial cancer of high-intermediate risk (PORTEC-2): an open-label, non-inferiority, randomised trial. Lancet. 2010;375:816-23.