Clinicopathologic and survival results in serous endometrium carcinoma and subgroup analysis for mixed serous and pure serous histology

OBJECTIVE: To review the clinicopathologic and survival outcomes of patients with serous endometrial cancer (EC) and to investigate subgroup analysis based on pure serous and mixed serous EC subtypes. MATERIAL AND METHODS: Patients who underwent EC surgery between 2002 and 2014 and who were reported as serous EC were enrolled in the study. All patients were diagnosed as having serous EC or mixed serous EC with serous component higher than 10% based on the postoperative pathology report. RESULTS: A total of 93 patients were analyzed. The median disease-free and overall survival (OS) durations were 49.6 and 32.2 months, respectively. Forty-three patients (46.2%) relapsed and 35 patients (37.6%) died. The histologic type was pure serous EC in 52 (55.9%) and mixed EC in 41 (44.9%) patients. There was no statistical difference between the pure serous and mixed serous groups in terms of age, International Federation of Gynecology and Obstetrics stage, lymphadenectomy, lymph node metastasis or adjuvant therapy combinations. Twenty-nine (55.8%) patients in the pure serous group and 14 (34.1%) in the mixed serous group hade recurrence (p=0.038). Twenty-five (48.1%) patients in the pure serous group and 10 (24.4%) in the mixed serous group died (p=0.034). In the pure serous group, the mean disease-free and OS durations were shorter than in the mixed serous group (59 vs. 81 months and 73 vs. 95 months, log-rank p=0.055 and 0.041, respectively). Histologic type was a significant prognostic factor on recurrence and OS in the univariate analysis (Hazard ratio: 2.404, 95% Confidence interval: 1.01-5.71; 2.027, respectively), but not in the multivariate analysis, which included disease stage and age of the patients. CONCLUSION: Compared with pure serous and mixed serous endometrium cancer groups, primary surgical treatments, clinicopathologic features and adjuvant treatments were similar, but there was a survival difference. Patients with pure serous cancer had a worse prognosis. However histology was not an independent factor for survival.