Clinical Characteristics and Risk Factors Analysis for the Recurrence of Pelvic Endodermal Sinus Tumors

Background: This study investigated the clinicopathological characteristics and factors influencing the recurrence of pelvic endodermal sinus tumor. Methods: Fifty-four cases were retrospectively analyzed from at the Zhejiang Cancer Hospital. Imaging and serological indicators were used to determine whether disease recurred, to evaluate progression-free survival, and to compare the influence of related factors on disease recurrence. SPSS 19.0 software was used for statistical analysis. Statistical significance was defined as p < 0.05. Results: The median age at initial treatment was 21 years (range, 11–52 years). Six patients had extragonadal endodermal sinus tumor, and four had histological features of endodermal sinus tumor combined with embryonal carcinoma. Thirty-nine patients underwent fertility-preserving surgery, 18 patients had a childbearing history, and eight patients had residual tumor after initial treatment. Twenty-six patients had a tumor diameter of more than 15 cm, and 30 patients had a serum α‑fetoprotein level greater than 10,000 ng/mL before initial management. The median follow-up time was 47.5 months (range, 14–212 months). During follow-up, 15 patients experience recurrence, with a recurrence rate of 27.8% and a 5-year PFS rate of 61.1%. In univariate analysis, the International Federation of Gynecology and Obstetrics stage (stage III-IV VS. I-II; HR= 10.054 p<0.001), residual tumor (yes VS. no for the first surgery; HR=5.014 p=0.001), histological features (endodermal sinus tumor combined with embryonal carcinoma VS. endodermal sinus tumor; HR=4.130 p=0.018), and use of platinum-based chemotherapy (courses≥3 VS. courses<3; HR= 0.188 p=0.004) were independent factors influencing recurrence; age, childbearing history, tumor site, tumor size, and serum α-fetoprotein level before initial management did not affect recurrence. In multivariate analysis, only stage was an independent risk factor for progression-free survival（stage III-IV VS. I-II; HR=6.923 p=0.019）. Conclusions: Stage is a prognostic factor for recurrence of pelvic endodermal sinus tumor. The first surgery should remove the tumor as completely as possible, and initial treatment should require a sufficient dose and full course of platinum-based chemotherapy, which may reduce the recurrence rate. Patients with endodermal sinus tumor and embryonal carcinoma may have increased susceptibility of recurrence.