{"entity":{"id":"placental-site-trophoblastic-tumour","kind":"cancer","name":"Placental-site trophoblastic tumour and epithelioid trophoblastic tumour","aka":["PSTT","ETT","Intermediate trophoblastic tumours","Epithelioid trophoblastic tumour","Placental site trophoblastic tumor"],"tldr":"Placental-site and epithelioid trophoblastic tumours are the rare, slow-growing forms of gestational trophoblastic neoplasia, arising from the intermediate trophoblast cells that anchor the placenta rather than the hormone-producing cells behind choriocarcinoma. They make little hCG and respond poorly to chemotherapy, so hysterectomy comes first, with platinum chemotherapy when they have spread.","summary":"Placental-site trophoblastic tumour (PSTT) and epithelioid trophoblastic tumour (ETT) arise from the intermediate trophoblast of the implantation site and the chorion laeve respectively, cell types that produce human placental lactogen rather than large amounts of hCG. Both present, usually in women in their thirties, with abnormal bleeding or amenorrhoea months or years after a normal pregnancy, miscarriage or mole, with serum hCG only mildly raised or even normal and often with a high proportion of hCG-free beta subunit; ETT can sit in the cervix or lower uterine segment and mimic squamous cell carcinoma. Unlike choriocarcinoma, they infiltrate the myometrium slowly, spread by lymphatics as well as blood, and are relatively resistant to chemotherapy, so hCG cannot be relied on to track them and imaging matters more. The FIGO score does not apply; the prognostic factors are stage, an interval of more than four years since the causative pregnancy, deep myometrial invasion, high mitotic count and, for PSTT, the presence of metastases, with the long interval the single strongest predictor of death.\n\nHysterectomy is the treatment for disease confined to the uterus and cures the great majority; fertility-sparing resection is attempted only in exceptional cases with small, localised tumours and carries a risk of recurrence. Metastatic disease and tumours arising more than four years after the antecedent pregnancy are treated with multi-agent platinum-containing chemotherapy, most often EP-EMA or TP/TE, with surgical removal of residual disease, and high-dose chemotherapy with autologous stem cell rescue has been used for resistant cases; EMA-CO alone is inadequate. Because response is measured by imaging as much as by hCG, FDG-PET is used to define residual disease before and after surgery. Immune checkpoint inhibitors are being tried in resistant intermediate trophoblastic tumours because, like other trophoblastic tumours, they express PD-L1, and pembrolizumab has produced responses in case reports. Registration with a national trophoblastic disease centre is recommended for every case because expert pathology is needed to separate PSTT and ETT from exaggerated placental site reaction, placental site nodule and choriocarcinoma, each of which is managed differently.","asOf":"2026-09-18","wikipedia":"https://en.wikipedia.org/wiki/Placental_site_trophoblastic_tumor","links":[{"label":"NCCN Gestational Trophoblastic Neoplasia","url":"https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1489"},{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Placental_site_trophoblastic_tumor"}],"tags":["subtype-page","gynaecologic"],"related":["low-risk-gtn","high-risk-gtn","gestational-trophoblastic"],"cancers":[],"sections":[],"technologies":["histopathology-ihc","mri","ct","pet-ct","fertility-preservation","cytotoxic-chemotherapy","autologous-stem-cell-transplant"],"targets":[],"drugs":["etoposide","cisplatin","methotrexate","dactinomycin","paclitaxel","pembrolizumab"],"companies":[],"institutions":[],"pathways":[],"terms":["tumour-markers","lymphadenectomy"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":["paper-schmid-placental-site-trophoblastic-tumour-outcomes-lancet-2009","paper-froeling-pstt-ett-intensified-therapy-bjc-2019","paper-figo-cancer-report-gestational-trophoblastic-disease-ijgo-2021"],"journals":[],"dependsOn":[],"notes":[],"group":"gynaecologic","burden":"The rarest forms of gestational trophoblastic neoplasia, a few percent of cases, presenting months to years after a pregnancy with bleeding and only modestly raised hCG; most are cured by hysterectomy, but metastatic disease is chemoresistant.","subtypes":["Placental-site trophoblastic tumour confined to the uterus (stage I; hysterectomy)","Epithelioid trophoblastic tumour of the uterus or cervix (hysterectomy)","Metastatic placental-site or epithelioid trophoblastic tumour (platinum-based chemotherapy and surgery)","Intermediate trophoblastic tumour arising more than four years after the causative pregnancy (worst prognosis)","Mixed trophoblastic tumours with choriocarcinoma components"],"biomarkers":["Serum hCG (low or normal; high hCG-free beta subunit fraction)","Human placental lactogen by immunohistochemistry (PSTT) and p63 (ETT)","Interval since the antecedent pregnancy (over four years predicts poor outcome)","Stage, depth of myometrial invasion and mitotic count","Genotyping to confirm gestational origin and identify the causative pregnancy","FDG-PET/CT for residual or metastatic disease"],"standardOfCare":[{"setting":"Diagnosis","approach":"Expert pathology with immunohistochemistry (human placental lactogen, p63, Ki-67) and genotyping; pelvic MRI, chest CT and FDG-PET; registration with a trophoblastic disease centre.","refs":["histopathology-ihc","mri","ct","pet-ct","tumour-markers"],"guideline":{"version":"NCCN Guidelines: Gestational Trophoblastic Neoplasia","url":"https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1489"}},{"setting":"Disease confined to the uterus","approach":"Total hysterectomy with ovarian preservation; pelvic node sampling considered; fertility-sparing local resection only in exceptional cases with close follow-up.","refs":["fertility-preservation","lymphadenectomy"],"guideline":{"version":"NCCN Guidelines: Gestational Trophoblastic Neoplasia","url":"https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1489"}},{"setting":"Metastatic disease or interval over four years","approach":"Multi-agent platinum-based chemotherapy (EP-EMA or TP/TE) with resection of residual disease; EMA-CO alone is insufficient.","refs":["etoposide","cisplatin","methotrexate","dactinomycin","paclitaxel","cytotoxic-chemotherapy"],"guideline":{"version":"NCCN Guidelines: Gestational Trophoblastic Neoplasia","url":"https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1489"}},{"setting":"Resistant disease","approach":"Surgical excision of chemoresistant deposits; high-dose chemotherapy with autologous stem cell rescue in selected cases; pembrolizumab in trials or on a case basis.","refs":["autologous-stem-cell-transplant","pembrolizumab","pet-ct"],"guideline":{"version":"NCCN Guidelines: Gestational Trophoblastic Neoplasia","url":"https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1489"}},{"setting":"Follow-up","approach":"Clinical review with hCG and imaging, because hCG alone can miss recurrence; prolonged surveillance for late relapse.","refs":["tumour-markers","mri"],"guideline":{"version":"NCCN Guidelines: Gestational Trophoblastic Neoplasia","url":"https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1489"}}],"stateOfArt":["Hysterectomy cures most women with disease confined to the uterus.","The interval from the causative pregnancy is recognised as the key prognostic factor.","Platinum-based regimens and surgery salvage a proportion of metastatic cases."],"history":[{"year":1976,"title":"Kurman, Scully and Norris describe placental-site trophoblastic tumour","refs":[]},{"year":1998,"title":"Shih and Kurman define epithelioid trophoblastic tumour","refs":[]},{"year":2009,"title":"Charing Cross series identifies an interval of over four years as the strongest predictor of death","refs":[]},{"year":2017,"title":"Pembrolizumab responses reported in resistant trophoblastic tumours including intermediate types","refs":["pembrolizumab"]}],"pipeline":["pembrolizumab"],"openProblems":["Numbers are too small for any trial; all treatment rests on registry series.","hCG is an unreliable marker, so recurrence can be missed.","Chemotherapy has limited activity and no targeted therapy exists.","Fertility-sparing surgery is rarely safe, which weighs heavily on young women."],"parent":"gestational-trophoblastic"},"route":"/cancers/placental-site-trophoblastic-tumour/","neighbours":{"cancer":[{"id":"gestational-trophoblastic","kind":"cancer","name":"Gestational trophoblastic neoplasia","route":"/cancers/gestational-trophoblastic/"},{"id":"high-risk-gtn","kind":"cancer","name":"High-risk gestational trophoblastic neoplasia (FIGO score 7 or more, including ultra-high-risk)","route":"/cancers/high-risk-gtn/"},{"id":"low-risk-gtn","kind":"cancer","name":"Low-risk gestational trophoblastic neoplasia (FIGO score 0 to 6)","route":"/cancers/low-risk-gtn/"}],"technology":[{"id":"autologous-stem-cell-transplant","kind":"technology","name":"Autologous stem cell transplant (high-dose therapy)","route":"/technologies/autologous-stem-cell-transplant/"},{"id":"ct","kind":"technology","name":"CT (computed tomography)","route":"/technologies/ct/"},{"id":"cytotoxic-chemotherapy","kind":"technology","name":"Cytotoxic chemotherapy","route":"/technologies/cytotoxic-chemotherapy/"},{"id":"histopathology-ihc","kind":"technology","name":"Histopathology & immunohistochemistry","route":"/technologies/histopathology-ihc/"},{"id":"mri","kind":"technology","name":"MRI","route":"/technologies/mri/"},{"id":"fertility-preservation","kind":"technology","name":"Oncofertility and fertility preservation","route":"/technologies/fertility-preservation/"},{"id":"pet-ct","kind":"technology","name":"PET/CT","route":"/technologies/pet-ct/"}],"drug":[{"id":"cisplatin","kind":"drug","name":"Cisplatin","route":"/drugs/cisplatin/"},{"id":"dactinomycin","kind":"drug","name":"Dactinomycin (actinomycin D)","route":"/drugs/dactinomycin/"},{"id":"etoposide","kind":"drug","name":"Etoposide","route":"/drugs/etoposide/"},{"id":"methotrexate","kind":"drug","name":"Methotrexate","route":"/drugs/methotrexate/"},{"id":"paclitaxel","kind":"drug","name":"Paclitaxel / nab-paclitaxel","route":"/drugs/paclitaxel/"},{"id":"pembrolizumab","kind":"drug","name":"Pembrolizumab","route":"/drugs/pembrolizumab/"}],"term":[{"id":"lymphadenectomy","kind":"term","name":"Lymphadenectomy (lymph node dissection)","route":"/terms/lymphadenectomy/"},{"id":"tumour-markers","kind":"term","name":"Tumour markers (CEA, LDH, chromogranin, thyroglobulin)","route":"/terms/tumour-markers/"}],"paper":[{"id":"paper-figo-cancer-report-gestational-trophoblastic-disease-ijgo-2021","kind":"paper","name":"FIGO Cancer Report 2021: diagnosis and management of gestational trophoblastic disease","route":"/key-papers/paper-figo-cancer-report-gestational-trophoblastic-disease-ijgo-2021/"},{"id":"paper-froeling-pstt-ett-intensified-therapy-bjc-2019","kind":"paper","name":"Intensified therapies improve survival and identification of novel prognostic factors for placental-site and epithelioid trophoblastic tumours","route":"/key-papers/paper-froeling-pstt-ett-intensified-therapy-bjc-2019/"},{"id":"paper-schmid-placental-site-trophoblastic-tumour-outcomes-lancet-2009","kind":"paper","name":"Prognostic markers and long-term outcome of placental-site trophoblastic tumours: a retrospective observational study","route":"/key-papers/paper-schmid-placental-site-trophoblastic-tumour-outcomes-lancet-2009/"}]}}