Placental-Site Gestational Trophoblastic Tumor Treatment
Given the rarity of this tumor, reports of therapeutic results are confined to relatively small case series with accrual extending for very long time periods. Therefore, few reliable comparisons among surgical approaches or chemotherapeutic regimens can be made. Nevertheless, there are distinctions in underlying biology between placental-site gestational trophoblastic tumors (PSTTs) and the other gestational trophoblastic tumors—particularly resistance to chemotherapy—that justify specific treatment strategies, such as the following:
- Tumors confined to the uterus (Féderation Internationale de Gynécologie et d'Obstétrique [FIGO] Stage I).
Hysterectomy is the treatment of choice.[1,2] In a relatively large retrospective population-based consecutive case series of 62 women with PSTT, 33 had disease confined to the uterus and were treated with hysterectomy (n = 17) or with hysterectomy plus chemotherapy (n = 16). Overall survival at 10 years was virtually identical between the two groups (90% and 91%, respectively). There was only one recurrence in the surgery group and two in the combination therapy group.[Level of evidence 3iDii] There is little evidence to guide the optimal extent of surgery (e.g., lymph node resection or oophorectomy).
- Tumors with extrauterine spread to genital structures (FIGO stage II).
Complete resection with or without adjuvant chemotherapy. Because the relapse rate is high after surgery and overall mortality in patients is high, adjuvant multiple-agent chemotherapy should be considered.[1,2][Level of evidence 3iDii] However, the impact of adjuvant therapy on overall mortality is uncertain.
- Metastatic tumors (FIGO stages III and IV).
Polyagent chemotherapy. A variety of regimens have been used, with no direct comparisons to determine whether one is superior. Some of the regimens include the following:[1,2]
In part because of the inherent chemoresistance of PSTTs, resection of tumors is often considered in addition to chemotherapy regimens used for high-risk gestational trophoblastic neoplasias. In retrospective series, adjuvant surgery, such as hysterectomy, excision of lung metastases, or removal of obstructing abdominal lesions, has been associated with favorable disease control. However, it is not clear as to what component of the favorable outcomes is attributable to the surgery versus patient selection factors.[2,3][Level of evidence 3iiiDii]