Concurrent Chemoradiation versus Radiotherapy Alone in Adjuvant Setting for High-Risk Endometrial Carcinoma

Background: For endometrial carcinoma, the main surgical treatment is total hysterectomy and bilateral salpingo-oophorectomy. Women with high-risk endometrial cancer have a relatively higher recurrence rates and poor prognosis following hysterectomy alone. Therefore, pelvic external beam radiotherapy has been the standard adjuvant treatment for these patients. This is a prospective study on patients with high-risk endometrial cancer evaluating the benefit of adding concurrent weekly paclitaxel with adjuvant radiotherapy, versus radiotherapy alone.
Methods: Eligible patients were randomized to Arm A; Concurrent chemotherapy with radiotherapy [CCRT], and Arm B; External beam pelvic radiotherapy alone [RTH]. Pelvic radiotherapy was 50.4Gy over 28 fractions, and chemotherapy course was weekly paclitaxel (50mg/m2) for 5 weeks. Patients were evaluated for treatment related toxicities, disease failures and survival.
Results: Seventy-one patients met the eligibility criteria of study protocol; 34 patients received CCRT; and 37 patients received RTH alone. The median age at time of diagnosis is 66 years. Regarding to tumor staging; 47% were Stage Ib, and other patients were stage II or III. Grade 3 toxicity were more in CCRT arm, and no grade 4 toxicity were recorded. The most common events were diarrhea and hematological affection. No significant difference in acute toxicities between treatment groups; except for hematological affection with concurrent paclitaxel [p=0.025]. Ten patients [14%] had a treatment failure; treatment failures are more in RTH group, but without statistical significance [p-value =0.51]. Estimated 2-years OS was around 86% with no statistical significance between both treatment arms [p-value = 0.83], and estimated 2-years DFS was; 83.2% for CCRT arm and 77.1% for RTH arm, with no statistical significance [p-value = 0.48].
Conclusion: Adding concurrent paclitaxel to pelvic radiotherapy in high-risk endometrial cancer patient is safe and tolerable, and tends to decrease treatment failures, even though this not translated to OS nor DFS improvement.