Clinicopathologic characteristics of placental site trophoblastic tumors

Objective: This study was aimed at analyzing the clinicopathological features and treatment of patients with placental site trophoblastic tumor (PSTT) in Shanghai, China, and to investigate high-risk factors for metastasis and relapse. Methods: Thirteen patients with placental site trophoblastic tumors who received treatment in the Obstetrics and Gynecology Hospital Affiliated with Fudan University in Shanghai, China, between Jan 2002 and July 2014 were reviewed. The cases were divided into two groups: confined and non-confined (CG and NCG, respectively). CG included patients in stage I without evidence of recurrence during the follow-up, whereas NCG included advanced stage or stage I with recurrent lesions. The clinical data, treatment and prognosis were collected from medical records. Results: The median age of the patients with placental site trophoblastic tumors was approximately 30.1 years. Gravidity ranged from 1 to 4 pregnancies. Antecedent pregnancies included term deliveries, abortions and complete molar pregnancies. The average time interval from antecedent pregnancy was 7.7 months. Irregular vaginal bleeding was the most common presentation. Most patients had a plasma hCG level less than 500 mIU/ml. All patients received either laparoscopically assisted vaginal hysterectomy or total abdominal hysterectomy. Patients in the NCG group were treated with combined chemotherapy such as EMA-CO or EP-EMA to achieve remission. No difference was observed in the expression of hPL, inhibin-α, p53 or the Ki-67 labeling index between the CG and NCG groups. However, there were statistically significant differences of age (≥ 35 years), gravidity (> 2), tumor size (≥ 30 mm) and myometrial invasion depth (≥ 1/2) in the NCG group (P = 0.002, 0.002, 0.015 and 0.024, respectively). Conclusions: This study showed that patient age, gravidity, tumor size and myometrial invasion depth might be predictors for metastasis and recurrence of PSTT. Surgery and combined chemotherapy are suggested in patients with those high-risk factors.