Radiation therapy with concurrent paclitaxel chemotherapy following surgery is an effective treatment for patients with high-risk endometrial cancer, according to a new study.
Endometrial cancer is the most common gynecologic malignancy. Patients with early stage disease are typically treated with surgery alone; however, patients with advanced endometrial cancer have higher instances of local or distant recurrence. Concurrent radiation and chemotherapy after surgery is used to reduce recurrence in patients with advanced disease. This study, published in the International Journal of Radiation Oncology • Biology • Physics (2014; doi:10.1016/j.ijrobp.2014.05.024), evaluated the efficacy and toxicity of concurrent chemoradiation with weekly paclitaxel in patients with stage III and IV endometrial cancer.
From January 2006 to March 2008, 57 patients from 20 institutions in Korea were included in the study. Patients eligible to participate in the study were age 20 to 80 years old, with a histologic diagnosis of International Federation of Gynecology and Obstetrics (FIGO) stage III or IV endometrioid adenocarcinoma with no history of prior surgery, chemotherapy, or radiation therapy for the treatment of other cancers. Of the 57 patients in this study, 12 patients (21.1%) had FIGO stage IIIA disease, 40 (70.1%) had FIGO stage IIIC disease, and five (8.8%) had FIGO stage IV disease. Fourteen patients (24.6%) had grade 1 tumors, 27 (47.3%) had grade 2 tumors, and 16 (28.1%) had grade 3 tumors.
Chemotherapy was suspended due to adverse toxic effects in two patients. Fifty-two patients were included in the study’s final analysis. Patients received follow-up for 5 years after surgery.
Severe toxicities observed during treatment were primarily hematologic toxicities. Of the 312 treatment cycles (52 patients received six cycles each), 52 episodes (16.7%) of grade 3 or 4 leukopenia were observed, and 35 episodes (11.2%) of grade 3 or 4 neutropenia were observed. Hematologic toxicity caused 98 cycles to be delayed 1 week, and a paclitaxel dose reduction was required for eight patients (15.3%) who experienced persistent neutropenia for more than 1 week.
Recurrent disease was found in 19 of the 52 patients (36.5%) in the final analysis. Eighteen patients (34.6%) experienced extrapelvic recurrence (lung, liver, bone, para-aortic, lymph node, or other sites). One patient (1.9%) had intrapelvic recurrence in the vaginal vault. The median time to the detection of recurrence was 12 months (range 3 to 24 months).
Survival data was available for all 52 patients included in the analysis. By the end of the 5-year follow-up period, nine patients (17.3%) had died of endometrial cancer. For all patients included in the study, the 5-year disease-free survival rate was 63.5%, and the overall survival rate was 82.7%.
“This study shows that concomitant radiation therapy and weekly paclitaxel chemotherapy is a reasonable treatment option for patients with advanced endometrial cancer that can reduce toxicity and reduce pelvic recurrence,” said Jae-Hoon Kim, MD, PhD, a co-author of the study, head of the department of obstetrics and gynecology at Gangnam Severance Hospital in Seoul, South Korea, and a professor in the Department of Obstetrics and Gynecology at Yonsei University College of Medicine in Seoul, South Korea.