Impact of adjuvant therapy on oncologic outcomes in uterine-confined clear cell carcinoma of the endometrium

Objectives

To determine the impact of adjuvant therapy on oncologic outcomes in patients with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage IA, IB, or II endometrial clear cell carcinoma (ECCC).

Methods

We conducted a retrospective review at 4 international institutions. Patients with newly diagnosed clinical stage I or II disease of either clear cell or mixed histology with a clear cell component treated between 01/01/2000–12/31/2015 were included. Oncologic outcomes were assessed for patients based on adjuvant treatment received, including chemotherapy, radiation, or chemotherapy with radiation.

Results

Of 125 patients identified and analyzed, 77 (61.6%) had clear cell histology and 118 (94.4%) had stage I disease. Median age at diagnosis was 65 years (range, 33–91). All patients underwent hysterectomy, bilateral salpingo-oophorectomy, and lymph node assessment. Twenty-five patients (20.0%) underwent surgical management alone and 100 (80.0%) received adjuvant therapy: 20 (16.0%) received postoperative chemotherapy, 47 (37.6%) received postoperative radiation, and 33 (26.4%) received postoperative chemotherapy with radiation. Median follow-up was 88.4 months (range, <1–234). Progression-free survival (PFS) or overall survival (OS) did not significantly differ between surgery alone and type of adjuvant therapy (P = 0.18 and P = 0.56, respectively). Patients with mixed ECCC did not have a survival advantage over those with pure ECCC (5-year PFS rate, 85.0% vs 82.7%, P = 0.77; 5-year OS rate, 88.3% vs 91.2%, P = 0.94).

Conclusions

Receipt of adjuvant therapy in surgically staged I/II ECCC did not appear to offer a survival advantage over observation alone. Adjuvant therapy in early-stage ECCC with consideration of molecular classification should be evaluated.