Role of adjuvant therapy in stage IIIC2 endometrial cancer.

Objective: The role of the different types of adjuvant treatments in endometrial cancer with para-aortic node metastases is unclear. The aim of this study was to report oncologic outcomes after adjuvant therapy in patients with stage IIIC2 endometrial cancer.

Methods: This retrospective single-institution study assessed patients with stage IIIC2 endometrial cancer who underwent primary surgery from January 1984 to December 2014. All patients had hysterectomy (±salpingo-oophorectomy) plus lymphadenectomy (para-aortic nodes, ±pelvic nodes). We included all patients with stage III endometrial cancer and documented para-aortic lymph node metastases (International Federation of Obstetrics and Gynecologists stage IIIC2). We excluded patients who did not provide consent, who had synchronous cancer, or who underwent neoadjuvant chemotherapy. Follow-up was restricted to the first 5 years post-operatively. Cox proportional hazards models, with age as the time scale, was used to evaluate associations of risk factors with disease-free survival and overall survival.

Results: Among 105 patients with documented adjuvant therapy, external beam radiotherapy was administered to 25 patients (24%), chemotherapy to 24 (23%), and a combination (chemotherapy and external beam radiotherapy) to 56 (53%) patients. Most patients receiving chemotherapy and external beam radiotherapy (80%) had chemotherapy first. The majority of relapses had a distant component (31/46, 67%) and only one patient had an isolated para-aortic recurrence. Non-endometrioid subtypes had poorer disease-free survival (HR 2.57; 95% CI 1.38 to 4.78) and poorer overall survival (HR 2.00; 95% CI 1.09 to 3.65) compared with endometrioid. Among patients with endometrioid histology (n=60), chemotherapy and external beam radiotherapy improved disease-free survival (HR 0.22; 95% CI 0.07 to 0.71) and overall survival (HR 0.28; 95% CI 0.09 to 0.89) compared with chemotherapy or external beam radiotherapy alone. Combination therapy did not improve prognosis for patients with non-endometrioid histology (n=45).

Conclusions: In our cohort of patients with stage IIIC2 endometrioid endometrial cancer, those receiving chemotherapy and external beam radiotherapy had improved survival compared with patients receiving chemotherapy or external beam radiotherapy alone. However, the prognosis of patients with non-endometrioid endometrial cancer remained poor, regardless of the adjuvant therapy administered. Distant recurrences were the most common sites of failure.