Does the Increased Rate of Serous Component (≤25% vs. >25%) Increase Recurrence in Endometrial Cancer With Serous Plus Endometrioid Histology?

Objective: The aim of the study is to investigate the effect of increasing serous component ratio on survival in endometrium cancer patients with serous plus endometrioid histology.

Methods: The study cases included 33 patients who underwent surgery for endometrial cancer and had serous plus endometrioid carcinoma based on the pathology report between 2005 and 2014. Univariate Cox regression analysis was used for evaluation of the effects of age, stage, lymphadenectomy, serous component ratio, lymphovascular space invasion, depth of myometrial invasion, and tumour size criteria on disease-free survival (DFS) and overall survival (OS).

Results: Median age was 63.0 years (range 45-81), and median follow-up duration was 54 months (range 13-144). Serous component ratio was less than 25% in 18 patients (55%) and more than 25% in 15 patients (45%). The rate of recurrence, DFS and OS were similar in the two groups (P = 0.695, P = 0.238, P = 0.134, respectively). Twenty-five patients (76%) were stage 1-2; 8 patients were (24%) stage 3-4. We evaluated the relationships of age, stage, lymphadenectomy, serous component ratio, lymphovascular invasion, myometrial invasion depth, and tumour size criteria with DFS and OS by univariate Cox regression analysis. Among these criteria, only the stage was detected to be in a significant relationship with DFS and OS (log rank test P < 0.001 and P = 0.01).

Conclusion: This study supported that the most important prognostic factor in patient with serous plus endometrioid histology is the stage of the cancer. Patients with a serous component ratio of less than 25% had similar recurrence and mortality rates to those with more than 25%.