MANAGEMENT OF PLACENTAL SITE TROPHOBLASTIC TUMORS

OBJECTIVE: To analyze the genetic background of tumors in patients wit h placental site trophoblastic tumors (PSTTs) and clinical outcome in patients treated for this rare variant of trophoblastic disease at a s ingle center. STUDY DESIGN: Analysis of all patients with PSTTs treate d at the Charing Cross Hospital between 1975 and 1995. RESULTS: We stu died the molecular genetics of a group of PSTTs using polymerase chain reaction allelotyping and GeneScan software. We were able to show, in the seven cases in which detailed molecular analysis was successful, that four of these PSTTs were from diploid, biparental pregnancies and three were androgenetic tumors following monospermic complete hydatid iform moles. For patients with PSTT localized to the uterus, the treat ment of choice is hysterectomy. The sensitivity of PSTT to current cyt otoxic chemotherapy is variable. Several patients have been cured usin g the etoposide, methotrexate, actinomycin D/cyclophosphamide, vincris tine schedule, but clinical impressions suggest that cisplatinum proba bly should be introduced into the chemotherapy schedule from the outse t in a schedule such as etoposide, cisplatin/etoposide, methotrexate, actinomycin D. CONCLUSION: PSTT is a very rate variant of gestational trophoblastic tumor, and its biologic behavior is clearly heterogeneou s. The treatment of choice for patients whose disease is limited to th e uterus is hysterectomy; for patients with more extensive or metastat ic disease, chemotherapy is indicated, but the clinical outcome is var iable. A long interval from the antecedent pregnancy to clinical prese ntation is a major adverse prognostic variable, and the outcome in pat ients whose last known pregnancy was > 2 years prior to presentation w ith PSTT is poor.