Introduction Adjuvant treatment options for advanced-stage endometrial cancer include chemotherapy (CT) and radiation therapy (RT), but the optimal treatment strategy is currently under debate. The aim of this study is to investigate the utilization of adjuvant RT and CT in women with stage III endometrial cancer and the impact on overall survival (OS) and disease-free survival (DFS) of each of these treatment modalities.
Materials and Methods
A retrospective review was performed of 40 patients with Stage III endometrial cancer who received adjuvant treatment at University Clinic for Radiotherapy and Oncology between 2012 and 2015. Postoperative treatment was administered based on performance status and medical comorbidities. Chemotherapy regimens comprised of Carboplatin (AUC 5) and Paclitaxel (175 mg/m2), a 3-week interval for 6 cycles (chemotherapy alone) and 4 cycles (sequential arm). RT was initiated within 2 to 4 weeks from the date of completion of chemotherapy and was delivered using 3-D EBRT with a total dose of 50 Gy in 25 fractions, for 5 weeks with/without an additional 7 Gy prescribed at a depth of 0.5 cm from the vaginal surface. The primary end points were overall survival (OS) and disease-free survival (DFS). Combined radiotherapy and chemotherapy was compared with radiotherapy alone and chemotherapy alone.
Results The distribution of surgical stages is as follows: IIIA accounted for 60% (n=24), stage IIIB accounted for 9.8%(n=4) and stage IIIC accounted for 30% (n=12).
The median age was 65 years and median follow-up was 35.5 months.There were 40 patients who received adjuvant treatment, 10% (n=4) received chemotherapy alone, 27.5% (n=11) received radiotherapy alone, and 62.5% (n=25) received sequential combined chemotherapy followed by external beam radiotherapy with/without vaginal vault brachytherapy. Relapse occurred in 55 % (n=22) of the patients ( both local and distant recurrence -36.36% (n=8), local recurrence in 27.27% (n=6), distant relapse in 36.36% (n=8)). OS and DFS at 3 years for patients receiving combined CT and RT, adjuvant RT alone and adjuvant CT alone were 68.8%, 41.26%, and 37.57% (OS) and 58.03%, 33.08%, and 24.96% (DFS), respectively. Disease-free survival (DFS) and overall survival (OS) were significantly longer in patients treated with combined radiotherapy and chemotherapy than in those treated with chemotherapy (DFS: P = 0.0005; hazard ratio HR, 5.677; OS: P = 0.0143; HR, 4.289) or radiotherapy alone (DFS: P = 0.0137; HR, 2.482; OS: P = 0.0151; HR, 3.036).
In conclusion, combined adjuvant chemotherapy and radiotherapy may improve prognosis and survival in patients with Stage III endometrial cancer compared to either modality alone. High grade and presence of lymphovascular space invasion are risk factors associated with higher risk of recurrence and poor prognosis.