Although early-stage endometrioid adenocarcinoma typically has a good prognosis, some patients have high-risk disease and would benefit from adjuvant chemotherapy and/or radiation therapy. In this article, Dr Alexander B. Olawaiye reviews his process for selecting adjuvant therapy in this patient population.

The most common form of endometrial cancer, endometrioid adenocarcinoma, is divided into low grade (grades 1 and 2) and high grade (grade 3). To determine whether a patient with early-stage grades 1 and 2 endometrioid adenocarcinoma requires adjuvant therapy, we evaluate them for uterine intermediate- and high-risk factors. These include the extent of myometrial invasion, whether the tumor is confined to the endometrium, and the presence of lymphovascular space invasion. Another risk factor that is not tumor related is the patient’s age. I would recommend adjuvant therapy for a 50-year-old woman with many risk factors and a 70-year-old woman with any risk factor because of the contribution of advanced age to the risk of recurrence.

In general, for patients with early-stage, high-risk endometrioid adenocarcinoma, if we decide to use adjuvant chemotherapy, we generally use carboplatin and paclitaxel. There are established guidelines and results from many randomized trials, including the PORTEC-1, GOG-99, PORTEC-2, PORTEC-3, and GOG-249 studies, to guide the selection of adjuvant radiation therapy. One thing that is clear from these trials is that the prolongation of overall survival has never been demonstrated, but there were progression-free survival advantages in many of them. I would use adjuvant radiation therapy in a patient who has not had surgical nodal staging but has high-risk uterine-related factors, and I would refer them for external beam radiation therapy rather than vaginal brachytherapy in this particular setting.

The PORTEC-2 study was done in a high-/intermediate-risk group of patients and showed no difference in benefit with using adjuvant external beam radiation vs vaginal brachytherapy, but the toxicity of external beam radiation therapy was much higher. Because the therapeutic benefit is not different in a patient with high-/intermediate-risk endometrioid adenocarcinoma, I would prioritize vaginal brachytherapy over external beam radiation therapy in appropriately selected patients.

GOG-249 looked at whether the addition of chemotherapy to radiation therapy would add benefit to the adjuvant therapy of patients with early-stage endometrial cancer vs radiation therapy alone. The results showed that there was no difference between treating with adjuvant radiation therapy alone or treating with adjuvant radiation therapy plus chemotherapy. So, the choice of adjuvant therapy is at the discretion of the doctor.